Biomathematics

General object of present experiments. The fact that the human body ad-justs itself to low environmental temperatures chiefly by constriction of the peripheral blood vessels, and to high atmospheric temperatures chiefly by increased secretion of sweat has long been a truism of physiology. We know 1, that physical regulation through constriction or dilatation of vessels is essentially a change in conductivity over the gradient between environ-mental and internal body temperature (Kleiber, 1932, Burton, 1934); and 2, that various segments of the body play relatively different roles in the elimination of heat (Maddock and Coller, 1933; Freeman, 1934). It has generally been assumed that insensible evaporative loss for subjects at rest is a roughly constant proportion of the total heat loss within the zone of thermal neutrality (Soderstrom and DuBois, 1917; Benedict and Root, 1926), provided the hydration of the body is normal (Manchester, 1931), the subjects not pathological (Lazlo and Schurmeyer, 1931), the humidity constant (Wiley and Newburgh, 1931), and the subjects in a post-absorp-

@article{doi101152ajplegacy193712011,
    author = "Winslow, C.‐E. A. and Herrington, L. P. and Gagge, A. P.",
    title = "PHYSIOLOGICAL REACTIONS OF THE HUMAN BODY TO VARYING ENVIRONMENTAL TEMPERATURES",
    year = "1937",
    journal = "American Journal of Physiology-Legacy Content",
    abstract = "General object of present experiments. The fact that the human body ad-justs itself to low environmental temperatures chiefly by constriction of the peripheral blood vessels, and to high atmospheric temperatures chiefly by increased secretion of sweat has long been a truism of physiology. We know 1, that physical regulation through constriction or dilatation of vessels is essentially a change in conductivity over the gradient between environ-mental and internal body temperature (Kleiber, 1932, Burton, 1934); and 2, that various segments of the body play relatively different roles in the elimination of heat (Maddock and Coller, 1933; Freeman, 1934). It has generally been assumed that insensible evaporative loss for subjects at rest is a roughly constant proportion of the total heat loss within the zone of thermal neutrality (Soderstrom and DuBois, 1917; Benedict and Root, 1926), provided the hydration of the body is normal (Manchester, 1931), the subjects not pathological (Lazlo and Schurmeyer, 1931), the humidity constant (Wiley and Newburgh, 1931), and the subjects in a post-absorp-",
    url = "https://doi.org/10.1152/ajplegacy.1937.120.1.1",
    doi = "10.1152/ajplegacy.1937.120.1.1",
    openalex = "W2336773552"
}

A presentation of an hypothesis to explain the great increase in size, the bipedal posture and the sudden disappearance of the giant reptiles, with an interpretation of their death in terms of the fatal susceptibility of present-day reptiles to temperatures in excess of 45⚬ C. and the known thermal limit of 45⚬ C. for most metazoans. While positive geological evidence for lethal high temperatures is not available, indirect evidence suggests the possibility of extreme heat in circum-equatorial regions, which may have been comparable in intensity to the low temperature extremes which left their evidence in glaciation. If such an explanation is acceptable, the devices of feathers and fur may have evolved originally as a protection of skin and body from excessive insolation, rather than to conserve a probably negligible internal heat. The eventual development of effective internal heat production in conjunction with the previously supplied insulation, may have come as a response to the ebbing heat waves and thus have produced the comparatively efficient homoiotherms of to-day. It is proposed that for accuracy and clarity the term "ectotherm" with the subtypes "heliotherm" and "thigmotherm" be substituted for "poikilotherm," and that "endotherm" be substituted for "homoiotherm." When considered from the viewpoint of the organic requirements of heat, there appears to be a definite progression away from the vagaries of thigmothermism through the adoption of heliothermism, with eventual stabilization by endothermism.

@article{doi101086280921,
    author = "Cowles, Raymond B.",
    title = "Additional Implications of Reptilian Sensitivity to High Temperatures",
    year = "1940",
    journal = "The American Naturalist",
    abstract = {A presentation of an hypothesis to explain the great increase in size, the bipedal posture and the sudden disappearance of the giant reptiles, with an interpretation of their death in terms of the fatal susceptibility of present-day reptiles to temperatures in excess of 45⚬ C. and the known thermal limit of 45⚬ C. for most metazoans. While positive geological evidence for lethal high temperatures is not available, indirect evidence suggests the possibility of extreme heat in circum-equatorial regions, which may have been comparable in intensity to the low temperature extremes which left their evidence in glaciation. If such an explanation is acceptable, the devices of feathers and fur may have evolved originally as a protection of skin and body from excessive insolation, rather than to conserve a probably negligible internal heat. The eventual development of effective internal heat production in conjunction with the previously supplied insulation, may have come as a response to the ebbing heat waves and thus have produced the comparatively efficient homoiotherms of to-day. It is proposed that for accuracy and clarity the term "ectotherm" with the subtypes "heliotherm" and "thigmotherm" be substituted for "poikilotherm," and that "endotherm" be substituted for "homoiotherm." When considered from the viewpoint of the organic requirements of heat, there appears to be a definite progression away from the vagaries of thigmothermism through the adoption of heliothermism, with eventual stabilization by endothermism.},
    url = "https://doi.org/10.1086/280921",
    doi = "10.1086/280921",
    openalex = "W2045166601"
}

Insulation measurements on raw skins from 16 arctic and 16 tropical mammals are given. There is, as would be expected, a good correlation between the thickness of the fur and the insulation. The smaller arctic mammals (weasels, lemmings) have much less insulation than the larger and overlap many of the tropical forms. From the size of a fox to the size of a moose there is no correlation between insulation and body size, they all have about the same insulation per surface area. When submerged in ice water, seal blubber retains about the same good insulation, as compared with measurements taken in 0° C. air. In the polar bear, heat transfer through the fur increases 25-50 times when submerged, because of complete wetting of the skin surface and absence of blubber. The beaver is slightly better off when submerged, as it retains an insulating layer of air in the fur next to the skin.

@article{doi1023071538740,
    author = "Scholander, P. F. and Walters, Vladimir and Hock, Raymond J. and Irving, Laurence",
    title = "BODY INSULATION OF SOME ARCTIC AND TROPICAL MAMMALS AND BIRDS",
    year = "1950",
    journal = "Biological Bulletin",
    abstract = "Insulation measurements on raw skins from 16 arctic and 16 tropical mammals are given. There is, as would be expected, a good correlation between the thickness of the fur and the insulation. The smaller arctic mammals (weasels, lemmings) have much less insulation than the larger and overlap many of the tropical forms. From the size of a fox to the size of a moose there is no correlation between insulation and body size, they all have about the same insulation per surface area. When submerged in ice water, seal blubber retains about the same good insulation, as compared with measurements taken in 0° C. air. In the polar bear, heat transfer through the fur increases 25-50 times when submerged, because of complete wetting of the skin surface and absence of blubber. The beaver is slightly better off when submerged, as it retains an insulating layer of air in the fur next to the skin.",
    url = "https://doi.org/10.2307/1538740",
    doi = "10.2307/1538740",
    openalex = "W1952779397"
}

@article{armitage1955biomathematics,
    author = "Armitage, P.",
    title = "BIOMATHEMATICS",
    year = "1955",
    journal = "BMJ",
    url = "https://doi.org/10.1136/bmj.1.4905.90-b",
    doi = "10.1136/bmj.1.4905.90-b",
    number = "4905",
    pages = "90-90",
    volume = "1"
}

@article{kendall1955biomathematics,
    author = "Kendall, M. G. and Smith, Cedric A. B.",
    title = "Biomathematics.",
    year = "1955",
    journal = "Biometrika",
    url = "https://doi.org/10.2307/2333448",
    doi = "10.2307/2333448",
    number = "1/2",
    pages = "271",
    volume = "42"
}

@article{doi101086physzool29130152379,
    author = "Dawson, William R. and Bartholomew, George A.",
    title = "Relation of Oxygen Consumption to Body Weight, Temperature, and Temperature Acclimation in Lizards Uta stansburiana and Sceloporus occidentalis",
    year = "1956",
    journal = "Physiological Zoology",
    url = "https://doi.org/10.1086/physzool.29.1.30152379",
    doi = "10.1086/physzool.29.1.30152379",
    openalex = "W2287930977"
}

@article{doi101038scientificamerican0459105,
    author = "Bogert, Charles M.",
    title = "How Reptiles Regulate their Body Temperature",
    year = "1959",
    journal = "Scientific American",
    url = "https://doi.org/10.1038/scientificamerican0459-105",
    doi = "10.1038/scientificamerican0459-105",
    openalex = "W2013754659"
}

ABSTRACT The natural internal temperature gradients during flight were reproduced in various medium and large insects by mounting freshly killed specimens in a wind tunnel and heating them with a high-frequency electric current. The heat flow from the flight muscles to other parts of the body and from the body were investigated. Comparison of dead and living insects showed that most of the heat transfer within the body is by conduction; circulation of the haemolymph during flight contributes little to the heat flow. The temperature excess is high throughout the pterothorax in a large insect; where there are no subcutaneous air sacs it is only about 10% less at the surface of the pterothorax than at the centre. Only about 5-15% of the heat generated in the flight muscles is conducted to the prothorax, head, abdomen and appendages, which remain near the temperature of the air. Usually not more than 10-15% of the heat escapes from the pterothorax by long-wave radiation in a large insect flying under a clear sky. Smaller insects lose relatively more of their heat by radiation. Radiation increases with the insect’s temperature but it is never sufficient to give much protection against overheating. Ordinarily 60-80% of the heat is dissipated from the surface of the pterothorax by convection. In convection from a naked insect the relationships between heat loss, the surface temperature excess, size, and wind speed are nearly the same as in convection from a smooth cylinder or sphere, if allowance is made for turbulence in the air flow over the insect. In dragonflies and denuded bees and moths heated in proportion to their pterothoracic volumes in a constant wind, the temperature excess was proportional to the 1·3-1·5 power of the average diameter of the pterothorax. The coats of hair on bumble-bees, hawk moths, and noctuid moths are excellent insulators against convective heat loss. At normal flying speeds they increase the temperature excess by 50-100% or more--in a large hawk moth probably by at least 8 or 9° C. The insulating value of a coat depends mostly on its density and on the size of the insect, and less on the length of the hair. In dragonflies the pterothorax is insulated nearly as effectively by the subcutaneous air sacs.

@article{doi101242jeb371186,
    author = "Church, N. S.",
    title = "Heat Loss and the Body Temperatures of Flying Insects",
    year = "1960",
    journal = "Journal of Experimental Biology",
    abstract = "ABSTRACT The natural internal temperature gradients during flight were reproduced in various medium and large insects by mounting freshly killed specimens in a wind tunnel and heating them with a high-frequency electric current. The heat flow from the flight muscles to other parts of the body and from the body were investigated. Comparison of dead and living insects showed that most of the heat transfer within the body is by conduction; circulation of the haemolymph during flight contributes little to the heat flow. The temperature excess is high throughout the pterothorax in a large insect; where there are no subcutaneous air sacs it is only about 10\% less at the surface of the pterothorax than at the centre. Only about 5-15\% of the heat generated in the flight muscles is conducted to the prothorax, head, abdomen and appendages, which remain near the temperature of the air. Usually not more than 10-15\% of the heat escapes from the pterothorax by long-wave radiation in a large insect flying under a clear sky. Smaller insects lose relatively more of their heat by radiation. Radiation increases with the insect’s temperature but it is never sufficient to give much protection against overheating. Ordinarily 60-80\% of the heat is dissipated from the surface of the pterothorax by convection. In convection from a naked insect the relationships between heat loss, the surface temperature excess, size, and wind speed are nearly the same as in convection from a smooth cylinder or sphere, if allowance is made for turbulence in the air flow over the insect. In dragonflies and denuded bees and moths heated in proportion to their pterothoracic volumes in a constant wind, the temperature excess was proportional to the 1·3-1·5 power of the average diameter of the pterothorax. The coats of hair on bumble-bees, hawk moths, and noctuid moths are excellent insulators against convective heat loss. At normal flying speeds they increase the temperature excess by 50-100\% or more--in a large hawk moth probably by at least 8 or 9° C. The insulating value of a coat depends mostly on its density and on the size of the insect, and less on the length of the hair. In dragonflies the pterothorax is insulated nearly as effectively by the subcutaneous air sacs.",
    url = "https://doi.org/10.1242/jeb.37.1.186",
    doi = "10.1242/jeb.37.1.186",
    openalex = "W2913503931"
}

@article{openalexw195142154,
    author = "Hemmingsen, Axel M. and Hemmingsen, Edvard A. and Hemmingsen, Sean M.",
    title = "Energy metabolism as related to body size and respiratory surfaces, and its evolution",
    year = "1960",
    journal = "Medical Entomology and Zoology",
    openalex = "W195142154"
}

@article{doi101086physzool36330152307,
    author = "Bartholomew, George A. and Tucker, Vance A.",
    title = "Control of Changes in Body Temperature, Metabolism, and Circulation by the Agamid Lizard, Amphibolurus barbatus",
    year = "1963",
    journal = "Physiological Zoology",
    url = "https://doi.org/10.1086/physzool.36.3.30152307",
    doi = "10.1086/physzool.36.3.30152307",
    openalex = "W2327944913"
}

@article{doi101038204355a0,
    author = "Mackay, R. Stuart",
    title = "Galapagos Tortoise and Marine Iguana Deep Body Temperatures Measured by Radio Telemetry",
    year = "1964",
    journal = "Nature",
    url = "https://doi.org/10.1038/204355a0",
    doi = "10.1038/204355a0",
    openalex = "W1966725475"
}

@article{doi101086physzool37330152398,
    author = "Heath, James E.",
    title = "Head-Body Temperature Differences in Horned Lizards",
    year = "1964",
    journal = "Physiological Zoology",
    url = "https://doi.org/10.1086/physzool.37.3.30152398",
    doi = "10.1086/physzool.37.3.30152398",
    openalex = "W2290233138"
}

@article{doi101086physzool37430152753,
    author = "Bartholomew, George A. and Tucker, Vance A.",
    title = "Size, Body Temperature, Thermal Conductance, Oxygen Consumption, and Heart Rate in Australian Varanid Lizards",
    year = "1964",
    journal = "Physiological Zoology",
    url = "https://doi.org/10.1086/physzool.37.4.30152753",
    doi = "10.1086/physzool.37.4.30152753",
    openalex = "W2255952903",
    references = "doi101086281295, doi101086physzool29130152379, doi101086physzool31230155383, doi101086physzool33230152297, doi101086physzool36330152307, doi101086physzool36330152308, doi101098rstb19030001, openalexw195142154"
}

@article{brattstrom1965body,
    author = "Brattstrom, Bayard H.",
    title = "Body Temperatures of Reptiles",
    year = "1965",
    journal = "American Midland Naturalist",
    url = "https://doi.org/10.2307/2423461",
    doi = "10.2307/2423461",
    number = "2",
    openalex = "W2018686700",
    pages = "376",
    volume = "73",
    references = "doi101038scientificamerican0459105, doi101086physzool34230152688, doi101086physzool36330152307, doi101111j155856461949tb00021x, doi101111j155856461961tb03132x, doi101126science122315873, doi101126science1353504670, doi1023071441115, doi1023071932171, doi1023071948638, openalexw1892056552"
}

The range of temperatures preferred by each species appears to be critically adjusted to a level compatible with the maximum tolerable temerature for the testes. However, continuous exposures even to preferred temperatures may be detrimental to both reproductive and somatic tissues. Loss of appetite and weight at high temperatures indicates a general systemic disorder, and spermatogenic failure may result from this rather than from heat per se. The lizards' use of high temperatures is evidently restricted by both systemic and reproductive heat sensitivities.

@article{doi1023071440991,
    author = "Licht, Paul",
    title = "The Relation between Preferred Body Temperatures and Testicular Heat Sensitivity in Lizards",
    year = "1965",
    journal = "Copeia",
    abstract = "The range of temperatures preferred by each species appears to be critically adjusted to a level compatible with the maximum tolerable temerature for the testes. However, continuous exposures even to preferred temperatures may be detrimental to both reproductive and somatic tissues. Loss of appetite and weight at high temperatures indicates a general systemic disorder, and spermatogenic failure may result from this rather than from heat per se. The lizards' use of high temperatures is evidently restricted by both systemic and reproductive heat sensitivities.",
    url = "https://doi.org/10.2307/1440991",
    doi = "10.2307/1440991",
    openalex = "W2312515487",
    references = "doi101086281249"
}

ABSTRACT Oxygen consumption, stroke volume, heart rate and the difference in oxygen contents of arterial and venous blood (AV difference) were measured in the resting iguana at body temperatures of 20, 30 and 38° C. Oxygen consumption increased by a factor of 4·4 as temperature changed from 20 to 38° C. This increase was accomplished by a decrease in stroke volume by a factor of 0·5, and increases in heart rate and A V difference by factors of 4-1 and 2-2, respectively. During activity increases in oxygen consumption at a given temperature were accompanied by increases in heart rate and A V difference, but stroke volume did not change consistently. The percentage saturation of arterial blood with oxygen in the iguana may differ in the right and left systemic arches. In some lizards, both arches carried equally saturated blood, but in others the left arch carried blood containing less oxygen than the right arch. An hypothesis is presented concerning the function of the double systemic arches and incompletely divided ventricles of lizards. These structures may be a device for permitting increased cardiac output associated with thermoregulation to bypass the lungs while maintaining a supply of well-oxygenated blood to the head. Data on oxygen capacity, percentage saturation of blood with oxygen, haematocrit and pH of iguana blood are included in this study. This study was supported by a National Science Foundation Postdoctoral Fellowship. I am indebted to Prof. W. R. Dawson, who provided laboratory facilities and advice to make this study possible.

@article{doi101242jeb44177,
    author = "Tucker, Vance A.",
    title = "Oxygen Transport by the Circulatory System of the Green Iguana (Iguana Iguana) at Different Body Temperatures",
    year = "1966",
    journal = "Journal of Experimental Biology",
    abstract = "ABSTRACT Oxygen consumption, stroke volume, heart rate and the difference in oxygen contents of arterial and venous blood (AV difference) were measured in the resting iguana at body temperatures of 20, 30 and 38° C. Oxygen consumption increased by a factor of 4·4 as temperature changed from 20 to 38° C. This increase was accomplished by a decrease in stroke volume by a factor of 0·5, and increases in heart rate and A V difference by factors of 4-1 and 2-2, respectively. During activity increases in oxygen consumption at a given temperature were accompanied by increases in heart rate and A V difference, but stroke volume did not change consistently. The percentage saturation of arterial blood with oxygen in the iguana may differ in the right and left systemic arches. In some lizards, both arches carried equally saturated blood, but in others the left arch carried blood containing less oxygen than the right arch. An hypothesis is presented concerning the function of the double systemic arches and incompletely divided ventricles of lizards. These structures may be a device for permitting increased cardiac output associated with thermoregulation to bypass the lungs while maintaining a supply of well-oxygenated blood to the head. Data on oxygen capacity, percentage saturation of blood with oxygen, haematocrit and pH of iguana blood are included in this study. This study was supported by a National Science Foundation Postdoctoral Fellowship. I am indebted to Prof. W. R. Dawson, who provided laboratory facilities and advice to make this study possible.",
    url = "https://doi.org/10.1242/jeb.44.1.77",
    doi = "10.1242/jeb.44.1.77",
    openalex = "W2345293171"
}

Lizards (Tiliqua scincoides) regulated their internal body temperature by moving back and forth between 15 degrees and 45 degrees C environments to maintain colonic and brain temperatures between 30 degrees and 37 degrees C. A pair of thermodes were implanted across the preoptic region of the brain stem, and a reentrant tube for a thermocouple was implanted in the brain stem. Heating the brain stem to 41 degrees C activated the exit response from the hot environment at a colonic temperature 1 degrees to 2 degrees C lower than normal, whereas cooling the brain stem to 25 degrees C delayed the exit from the hot environment until the colonic temperature was 1 degrees to 2 degrees C higher than normal. The behavioral thermoregulatory responses of this ectotherm appear to be activated by a combination of hypothalamic and other body temperatures.

@article{doi101126science15637791260,
    author = "Hammel, H. T. and Caldwell, Fred T. and Abrams, Robert M.",
    title = "Regulation of Body Temperature in the Blue-Tongued Lizard",
    year = "1967",
    journal = "Science",
    abstract = "Lizards (Tiliqua scincoides) regulated their internal body temperature by moving back and forth between 15 degrees and 45 degrees C environments to maintain colonic and brain temperatures between 30 degrees and 37 degrees C. A pair of thermodes were implanted across the preoptic region of the brain stem, and a reentrant tube for a thermocouple was implanted in the brain stem. Heating the brain stem to 41 degrees C activated the exit response from the hot environment at a colonic temperature 1 degrees to 2 degrees C lower than normal, whereas cooling the brain stem to 25 degrees C delayed the exit from the hot environment until the colonic temperature was 1 degrees to 2 degrees C higher than normal. The behavioral thermoregulatory responses of this ectotherm appear to be activated by a combination of hypothalamic and other body temperatures.",
    url = "https://doi.org/10.1126/science.156.3779.1260",
    doi = "10.1126/science.156.3779.1260",
    openalex = "W2074614729"
}

An exponential relation exists between standard energy metabolism and body weight in organisms that is described by the generalized equation: Metabolic Rate = a (Body Weight) b (a) where a and b are empirically derived constants.This equation can be rewritten in the more convenient logarithmic form: log Metabolic Rate = log a + b log Body Weight (b) recognizable as a mathematical expression of a straight line.Hemmingsen (1950, 1960) has reviewed the relation of energy metabolism to body size in all organisms, and argues that a b-value of 0.75 best describes the existing data for unicellular organisms, plants, poikilothermal and homeothermal animals.However, the observed limits of b are 0.63-1.0among individual groups (Zeuthen, 1953, and others).Despite recent increased interest in avian bioenergetics, a definitive statement concerning the relationship between metabolic rate and body weight in birds has been lacking.Several formulas for this relationship have been presented.Brody and Proctor (1932) fitted the following equation to data on avian body weight and metabolism: log M = log 89 + 0.64 log W (c) where M is in kcal/day and W is in kilograms.This expression, in which the regression coefficient (b) of 0.64 differs markedly from those obtained from mammals (0.73-0.76) by Brody and Proctor (1932), Kleiber (1932, 1947), Benedict (1938), and Brody (1945), has been generally accepted for birds until recently.King and Farner (1961) have commented that "on theoretical grounds there seems to be no reason to believe a priori that the relationship of metabolic rate and body weight should be very different in the homoiotherm classes."With many more metabolic values than were available previously, King and Farner re-analyzed the relationship, using more rigorous criteria for including data in their computations.They obtained the following equation: log M = log 74.3 + 0.744 log W * 0.074.(d) King and Farner believe that this equation is superior to that of Brody and Proctor (1932) in predicting the metabolic rates of birds weighing more than 0.1 kg.However, they concluded that it does not adequately portray the metabolism-weight relationship for smaller birds.Equation (d) is statistically indistinguishable from Kleiber' s (1947) equation for mammals, and it is therefore doubtful that the metabolism-weight relationship for birds weighing more than 0.1 kg really differs from that in mammals.King and Farner (1961) discuss the possibility that the avian relationship may be curvilinear in the lower ranges of body weight, since small birds have higher metabolic rates than predicted by their equation.Virtually all of the small birds (< 0.1 kg) are passerines, whereas all but two of the species weighing more than 0.1 kg belong to other orders.Dawson and Lasiewski have suggested (see Lasiewski, 1963; Lasiewski et al., 1964) that passerines as a group show the same weight-regression coefficient as nonpasserines, but have a higher metabolism per unit weight than nonpasserines of comparable size.Documentation of this suggestion required additional data on large passerines and small nonpasserines.Now that these are available, it is

@article{doi1023071366368,
    author = "Lasiewski, Robert C. and Dawson, William R.",
    title = "A Re-Examination of the Relation between Standard Metabolic Rate and Body Weight in Birds",
    year = "1967",
    journal = "Ornithological Applications",
    abstract = {An exponential relation exists between standard energy metabolism and body weight in organisms that is described by the generalized equation: Metabolic Rate = a (Body Weight) b (a) where a and b are empirically derived constants.This equation can be rewritten in the more convenient logarithmic form: log Metabolic Rate = log a + b log Body Weight (b) recognizable as a mathematical expression of a straight line.Hemmingsen (1950, 1960) has reviewed the relation of energy metabolism to body size in all organisms, and argues that a b-value of 0.75 best describes the existing data for unicellular organisms, plants, poikilothermal and homeothermal animals.However, the observed limits of b are 0.63-1.0among individual groups (Zeuthen, 1953, and others).Despite recent increased interest in avian bioenergetics, a definitive statement concerning the relationship between metabolic rate and body weight in birds has been lacking.Several formulas for this relationship have been presented.Brody and Proctor (1932) fitted the following equation to data on avian body weight and metabolism: log M = log 89 + 0.64 log W (c) where M is in kcal/day and W is in kilograms.This expression, in which the regression coefficient (b) of 0.64 differs markedly from those obtained from mammals (0.73-0.76) by Brody and Proctor (1932), Kleiber (1932, 1947), Benedict (1938), and Brody (1945), has been generally accepted for birds until recently.King and Farner (1961) have commented that "on theoretical grounds there seems to be no reason to believe a priori that the relationship of metabolic rate and body weight should be very different in the homoiotherm classes."With many more metabolic values than were available previously, King and Farner re-analyzed the relationship, using more rigorous criteria for including data in their computations.They obtained the following equation: log M = log 74.3 + 0.744 log W * 0.074.(d) King and Farner believe that this equation is superior to that of Brody and Proctor (1932) in predicting the metabolic rates of birds weighing more than 0.1 kg.However, they concluded that it does not adequately portray the metabolism-weight relationship for smaller birds.Equation (d) is statistically indistinguishable from Kleiber' s (1947) equation for mammals, and it is therefore doubtful that the metabolism-weight relationship for birds weighing more than 0.1 kg really differs from that in mammals.King and Farner (1961) discuss the possibility that the avian relationship may be curvilinear in the lower ranges of body weight, since small birds have higher metabolic rates than predicted by their equation.Virtually all of the small birds (< 0.1 kg) are passerines, whereas all but two of the species weighing more than 0.1 kg belong to other orders.Dawson and Lasiewski have suggested (see Lasiewski, 1963; Lasiewski et al., 1964) that passerines as a group show the same weight-regression coefficient as nonpasserines, but have a higher metabolism per unit weight than nonpasserines of comparable size.Documentation of this suggestion required additional data on large passerines and small nonpasserines.Now that these are available, it is},
    url = "https://doi.org/10.2307/1366368",
    doi = "10.2307/1366368",
    openalex = "W2335031573",
    references = "doi101152physrev1947274511, openalexw195142154"
}

Macrophage polarization refers to how macrophages have been activated at a given point in space and time. Polarization is not fixed, as macrophages are sufficiently plastic to integrate multiple signals, such as those from microbes, damaged tissues, and...Read More

@article{doi101146annurevph30030168003233,
    author = "Hammel, H. T. and Pierce, JH",
    title = "Regulation of Internal Body Temperature",
    year = "1968",
    journal = "Annual Review of Physiology",
    abstract = "Macrophage polarization refers to how macrophages have been activated at a given point in space and time. Polarization is not fixed, as macrophages are sufficiently plastic to integrate multiple signals, such as those from microbes, damaged tissues, and...Read More",
    url = "https://doi.org/10.1146/annurev.ph.30.030168.003233",
    doi = "10.1146/annurev.ph.30.030168.003233",
    openalex = "W2174431287",
    references = "doi101002jcp1030570302, doi1010160010406x65903208, doi101086physzool35330152807, doi101111j155856461961tb03132x, doi1023071441115"
}

@article{doi101152ajplegacy197021941104,
    author = "Taylor, CR and Schmidt‐Nielsen, Knut and Raab, JL",
    title = "Scaling of energetic cost of running to body size in mammals",
    year = "1970",
    journal = "American Journal of Physiology-Legacy Content",
    url = "https://doi.org/10.1152/ajplegacy.1970.219.4.1104",
    doi = "10.1152/ajplegacy.1970.219.4.1104",
    openalex = "W2107249086",
    references = "doi101007bf01661859, doi1010160010406x70910066, doi101038scientificamerican056970, doi101111j174817161961tb02232x, doi101152jappl1963182367, doi101152jappl196520119, doi103733hilgv06n11p315, openalexw1562852527, openalexw195142154, openalexw2566063334"
}

@article{smith1970biomathematics,
    author = "Smith, C. A. B. and Bartlett, M. S.",
    title = "Biomathematics.",
    year = "1970",
    journal = "Journal of the Royal Statistical Society. Series A (General)",
    url = "https://doi.org/10.2307/2343821",
    doi = "10.2307/2343821",
    number = "1",
    pages = "101",
    volume = "133"
}

@article{edwards1972biomathematics,
    author = "Edwards, J. H.",
    title = "Biomathematics",
    year = "1972",
    journal = "Journal of Medical Genetics",
    url = "https://doi.org/10.1136/jmg.9.4.485",
    doi = "10.1136/jmg.9.4.485",
    number = "4",
    pages = "485.1-485",
    volume = "9"
}

@article{groth1972biomathematics,
    author = "Groth, Torgny",
    title = "Biomathematics",
    year = "1972",
    journal = "Computer Programs in Biomedicine",
    url = "https://doi.org/10.1016/0010-468x(72)90021-9",
    doi = "10.1016/0010-468x(72)90021-9",
    number = "4",
    pages = "322",
    volume = "2"
}

@article{spotila1973a,
    author = "Spotila, James R. and Lommen, Paul W. and Bakken, George S. and Gates, David M.",
    title = "A Mathematical Model for Body Temperatures of Large Reptiles: Implications for Dinosaur Ecology",
    year = "1973",
    journal = "The American Naturalist",
    url = "https://doi.org/10.1086/282842",
    doi = "10.1086/282842",
    number = "955",
    openalex = "W1999252436",
    pages = "391-404",
    volume = "107",
    references = "doi1010160010406x65903208, doi1010160010406x7090592x, doi101086281249, doi101086282714, doi101086physzool36330152307, doi101086physzool37330152398, doi101111j155856461949tb00021x, doi101111j155856461968tb03995x, doi1023071948545, openalexw1892056552"
}

@misc{spotila1973a1,
    author = "Spotila, J. R. et al",
    title = "A mathematical model for body temperatures of large reptiles",
    year = "1973",
    howpublished = "Implications for dinosaur ecology: American Naturalist, v. 107, p. 391-404",
    note = "talkorigins\_source = {true}; raw\_reference = {Spotila, J. R. et al., 1973, A mathematical model for body temperatures of large reptiles: Implications for dinosaur ecology: American Naturalist, v. 107, p. 391-404.}"
}

@article{vitt1974body,
    author = "Vitt, Laurie J.",
    title = "Body Temperatures of High Latitude Reptiles",
    year = "1974",
    journal = "Copeia",
    url = "https://doi.org/10.2307/1443034",
    doi = "10.2307/1443034",
    number = "1",
    openalex = "W2333183033",
    pages = "255",
    volume = "1974"
}

@incollection{bartlett1975biomathematics,
    author = "Bartlett, M. S.",
    title = "Biomathematics",
    year = "1975",
    booktitle = "Probability, Statistics and Time",
    url = "https://doi.org/10.1007/978-94-009-5889-0\_5",
    doi = "10.1007/978-94-009-5889-0\_5",
    pages = "72-97"
}

@incollection{dawson1975on,
    author = "Dawson, William R.",
    title = "On the Physiological Significance of the Preferred Body Temperatures of Reptiles",
    year = "1975",
    booktitle = "Ecological Studies",
    url = "https://doi.org/10.1007/978-3-642-87810-7\_25",
    doi = "10.1007/978-3-642-87810-7\_25",
    openalex = "W2050769086",
    pages = "443-473",
    references = "brattstrom1965body, doi101086physzool36330152307, doi101086physzool37330152398, doi101086physzool37430152753, doi101111j109636421961tb00220x, doi101113jphysiol2014280446, doi101126science122315873, doi101126science15838041050, doi1023071948545, openalexw1892056552, openalexw2983381470"
}

@book{machin1976biomathematics,
    author = "Machin, David",
    title = "Biomathematics",
    year = "1976",
    url = "https://doi.org/10.1007/978-1-349-02554-1",
    doi = "10.1007/978-1-349-02554-1"
}

A simple energy budget equation is developed to yield a bioenergetics model designed to simulate fish growth. Parameters for the model are estimated from the literature for application to yellow perch (Perca flavescens) and walleye (Stizostedion vitreum vitreum). Simulations are presented that demonstrate model output as functions of body size, activity level, ration level, food quality, and environmental temperature. Sensitivity analyses identify the importance of food consumption, activity, and excretion as biological processes represented in the parameters. On the basis of temperature conditions in selected lakes and specified feeding levels, simulations are presented to quantify the importance of year-to-year variation of temperature in determining growth. In heterothermal systems, temperature selection by percids can have a significant effect on growth. For walleye on fixed rations, annual growth can vary from zero to twofold increments due entirely to differences in summer temperatures. Variations in food quality have lesser effects. Key words: Perca, Stizostedion, bioenergetics model, growth, sensitivity, simulations

@article{doi101139f77258,
    author = "Kitchell, James F. and Stewart, Donald J. and Weininger, David",
    title = "Applications of a Bioenergetics Model to Yellow Perch (Perca flavescens) and Walleye (Stizostedion vitreum vitreum)",
    year = "1977",
    journal = "Journal of the Fisheries Research Board of Canada",
    abstract = "A simple energy budget equation is developed to yield a bioenergetics model designed to simulate fish growth. Parameters for the model are estimated from the literature for application to yellow perch (Perca flavescens) and walleye (Stizostedion vitreum vitreum). Simulations are presented that demonstrate model output as functions of body size, activity level, ration level, food quality, and environmental temperature. Sensitivity analyses identify the importance of food consumption, activity, and excretion as biological processes represented in the parameters. On the basis of temperature conditions in selected lakes and specified feeding levels, simulations are presented to quantify the importance of year-to-year variation of temperature in determining growth. In heterothermal systems, temperature selection by percids can have a significant effect on growth. For walleye on fixed rations, annual growth can vary from zero to twofold increments due entirely to differences in summer temperatures. Variations in food quality have lesser effects. Key words: Perca, Stizostedion, bioenergetics model, growth, sensitivity, simulations",
    url = "https://doi.org/10.1139/f77-258",
    doi = "10.1139/f77-258",
    openalex = "W1988326917"
}

We discuss seasonal variation in thermoregulatory behavior and its consequences on body temperature for 12 species of diurnal lizards in the southern Kalahari semidesert of Africa and also evaluate several methods of attempting to document thermoregulatory behavior using a descriptive data base. Lizards vary time of activity among seasons, which limits the variation in ambient conditions actually experienced. Ground—dwelling lizards and probably arboreal lizards move nonrandomly with respect to sun and shade; thus the percentage of lizards in sun in inversely proportional to air temperature. Arboreal lizards shift to higher perches at midday in summer and to logs or ground in winter thus decreasing and increasing incident heat loads, respectively. Both juveniles and adults of 3 species, only juveniles of 2 species, and only adults in 1 species are active in winter: both adults and juveniles of 6 species brumate [= hibernate]. Mean body temperature (T b) varies within days and among months and is positively correlated with corresponding mean air temperature (T a) in almost all species. Nonetheless, correlation and regression analysis suggests that thermoregulatory behaviors reduce the impact of variations in ambient conditions on Kalahari lizards. The mean T b of different species reflect evolutionary relationships. In summer, mean T b is proportional to the percentage of lizards in sun and with the tendency of lizards to be active only in summer. Thus, lizards with inferred low optimal temperatures are active during more months of the year.

@article{doi1023071936926,
    author = "Huey, Raymond B. and Pianka, Eric R.",
    title = "Seasonal Variation in Thermoregulatory Behavior and Body Temperature of Diurnal Kalahari Lizards",
    year = "1977",
    journal = "Ecology",
    abstract = "We discuss seasonal variation in thermoregulatory behavior and its consequences on body temperature for 12 species of diurnal lizards in the southern Kalahari semidesert of Africa and also evaluate several methods of attempting to document thermoregulatory behavior using a descriptive data base. Lizards vary time of activity among seasons, which limits the variation in ambient conditions actually experienced. Ground—dwelling lizards and probably arboreal lizards move nonrandomly with respect to sun and shade; thus the percentage of lizards in sun in inversely proportional to air temperature. Arboreal lizards shift to higher perches at midday in summer and to logs or ground in winter thus decreasing and increasing incident heat loads, respectively. Both juveniles and adults of 3 species, only juveniles of 2 species, and only adults in 1 species are active in winter: both adults and juveniles of 6 species brumate [= hibernate]. Mean body temperature (T b) varies within days and among months and is positively correlated with corresponding mean air temperature (T a) in almost all species. Nonetheless, correlation and regression analysis suggests that thermoregulatory behaviors reduce the impact of variations in ambient conditions on Kalahari lizards. The mean T b of different species reflect evolutionary relationships. In summer, mean T b is proportional to the percentage of lizards in sun and with the tendency of lizards to be active only in summer. Thus, lizards with inferred low optimal temperatures are active during more months of the year.",
    url = "https://doi.org/10.2307/1936926",
    doi = "10.2307/1936926",
    openalex = "W2074094096",
    references = "doi1023071441115"
}

@article{busack1978body,
    author = "Busack, Stephen D.",
    title = "Body Temperatures and Live Weights of Five Spanish Amphibians and Reptiles",
    year = "1978",
    journal = "Journal of Herpetology",
    url = "https://doi.org/10.2307/1563420",
    doi = "10.2307/1563420",
    number = "2",
    openalex = "W2312769734",
    pages = "256",
    volume = "12"
}

@article{doi1023071443592,
    author = "Kluge, Arnold G. and d’A. Bellairs, A. and Cox, C. Barry",
    title = "Morphology and Biology of Reptiles",
    year = "1978",
    journal = "Copeia",
    url = "https://doi.org/10.2307/1443592",
    doi = "10.2307/1443592",
    openalex = "W1993113799"
}

Rectal body temperatures (BTs) of tuataras (Sphenodon punctatus) and of endemic, ovoviviparous gekkonid lizards—mainly Hoplodactylus maculatus (= H. pacificus) and Heteropholis manukanus —were taken together with ambient temperatures during early summer 1970 in areas of central New Zealand. The results, combined with earlier data, enable a number of conclusions to be drawn. (a) The preferred body temperature of heliotherm reptiles is best deduced from the mode of rectal BTS taken in the field, but that of non‐heliotherms, when unimodal, from the median or mean. (b) Among Gekkonoidea, specific thermal relations are highly variable in several ways. (c) Sphenodon foraged on cool nights at BTs of 10.5–12.5°c, yet basked in the forest by day at BTs up to 24°C; in pasture it apparently basks within the burrow entrance. (d) Similarly, H. maculatus foraged at night at BTs of 10–13°C, but by day thermoregulated at BTs up to 33°C by ‘indirect basking’ (under thin cover) or ‘protected basking’ (in crevices penetrated by solar radiation). The average BT of females was 2°C higher than that of males, presumably because many females were gravid. (e) H. manukanus is (tertiarily) diurnal, and thermoregulated by basking up to a BT of 31 °C. Towards evening it apparently cooled down voluntarily. (f) Whereas a high daytime BT probably assists digestion in nocturnal foragers, a voluntary low night‐time BT in diurnal reptiles may help to conserve energy.

@article{werner1978observations,
    author = "Werner, Y. L. and Whitaker, A. H.",
    title = "Observations and comments on the body temperatures of some New Zealand reptiles",
    year = "1978",
    journal = "New Zealand Journal of Zoology",
    abstract = "Rectal body temperatures (BTs) of tuataras (Sphenodon punctatus) and of endemic, ovoviviparous gekkonid lizards—mainly Hoplodactylus maculatus (= H. pacificus) and Heteropholis manukanus —were taken together with ambient temperatures during early summer 1970 in areas of central New Zealand. The results, combined with earlier data, enable a number of conclusions to be drawn. (a) The preferred body temperature of heliotherm reptiles is best deduced from the mode of rectal BTS taken in the field, but that of non‐heliotherms, when unimodal, from the median or mean. (b) Among Gekkonoidea, specific thermal relations are highly variable in several ways. (c) Sphenodon foraged on cool nights at BTs of 10.5–12.5°c, yet basked in the forest by day at BTs up to 24°C; in pasture it apparently basks within the burrow entrance. (d) Similarly, H. maculatus foraged at night at BTs of 10–13°C, but by day thermoregulated at BTs up to 33°C by ‘indirect basking’ (under thin cover) or ‘protected basking’ (in crevices penetrated by solar radiation). The average BT of females was 2°C higher than that of males, presumably because many females were gravid. (e) H. manukanus is (tertiarily) diurnal, and thermoregulated by basking up to a BT of 31 °C. Towards evening it apparently cooled down voluntarily. (f) Whereas a high daytime BT probably assists digestion in nocturnal foragers, a voluntary low night‐time BT in diurnal reptiles may help to conserve energy.",
    url = "https://doi.org/10.1080/03014223.1978.10428324",
    doi = "10.1080/03014223.1978.10428324",
    number = "2",
    openalex = "W2010642507",
    pages = "375-393",
    volume = "5",
    references = "brattstrom1965body, doi101111j155856461949tb00021x, doi101126science11282807, doi1023071440766, doi1023071441872, doi1023072405558, openalexw1892056552, openalexw2114241797, openalexw2560671010, openalexw389884042"
}

@article{doi101016s0003347282801371,
    author = "Hertz, Paul and Huey, Raymond B. and Nevo, Eviatar",
    title = "Fight versus flight: Body temperature influences defensive responses of lizards",
    year = "1982",
    journal = "Animal Behaviour",
    url = "https://doi.org/10.1016/s0003-3472(82)80137-1",
    doi = "10.1016/s0003-3472(82)80137-1",
    openalex = "W2019659419"
}

Four functional categories are denned to embrace the range of locomotor diversity of aquatic vertebrates; (1) body/caudal fin (BCF) periodic propulsion where locomotor movements repeat, as occurs in cruising and sprint swimming; (2) BCF transient propulsion where kinematics are brief and non-cylic, as occurs in fast-starts and powered turns; (3) median and paired fin (MPF) propulsion, with very diverse fin kinematics, used in slow swimming and precise maneuver; (4) occasional propulsion or “non-swimming.” Specialization in any one of these categories compromises performance in one or more of the others, thereby reducing locomotor diversity and hence behavioral options. Food characteristics influencing the role of locomotion in search and capture are; (1) distribution in space and/or time and (2) evasive capabilities. BCF periodic swimmers take food that is widely dispersed in space/time; BCF transient swimmers consume locally abundant evasive items and MPF swimmers consume non-evasive food in structurally complex habitats. Locomotor specialists under-utilize smaller food items in exposed habitats. This resource is exploited by smaller fish, which are locomotor generalists because of predation pressures. For such locomotor generalists, locomotor adaptations for food capture are of diminished importance and other adaptations such as suction and protrusible jaws in fish are common.

@article{doi101093icb241107,
    author = "Webb, Paul W.",
    title = "Body Form, Locomotion and Foraging in Aquatic Vertebrates",
    year = "1984",
    journal = "American Zoologist",
    abstract = "Four functional categories are denned to embrace the range of locomotor diversity of aquatic vertebrates; (1) body/caudal fin (BCF) periodic propulsion where locomotor movements repeat, as occurs in cruising and sprint swimming; (2) BCF transient propulsion where kinematics are brief and non-cylic, as occurs in fast-starts and powered turns; (3) median and paired fin (MPF) propulsion, with very diverse fin kinematics, used in slow swimming and precise maneuver; (4) occasional propulsion or “non-swimming.” Specialization in any one of these categories compromises performance in one or more of the others, thereby reducing locomotor diversity and hence behavioral options. Food characteristics influencing the role of locomotion in search and capture are; (1) distribution in space and/or time and (2) evasive capabilities. BCF periodic swimmers take food that is widely dispersed in space/time; BCF transient swimmers consume locally abundant evasive items and MPF swimmers consume non-evasive food in structurally complex habitats. Locomotor specialists under-utilize smaller food items in exposed habitats. This resource is exploited by smaller fish, which are locomotor generalists because of predation pressures. For such locomotor generalists, locomotor adaptations for food capture are of diminished importance and other adaptations such as suction and protrusible jaws in fish are common.",
    url = "https://doi.org/10.1093/icb/24.1.107",
    doi = "10.1093/icb/24.1.107",
    openalex = "W1984834887",
    references = "doi1023072530028"
}

A nonequilibrium heat-transfer model is used to calculate the extreme range of body temperatures available to ectotherms of different masses. At about 1 kg a transition occurs in the amplitudes imposed on a terrestrial ectotherm's potential range in body temperature by the daily cycling of the thermal environment. Animals smaller than 1 kg can choose a wide range of temperatures, whereas animals larger than 1 kg experience smaller ranges in Tb. The range in Tb that small insects experience is limited by the range in Ta, which, however, can be large in the boundary layer of perching surfaces. Data from the literature indicate that ectotherms in the range of sizes from 0.01 to 1 kg have limited ranges of Tb (about 30⚬ C). The model predicts that it could be as large as 55⚬ C, 15⚬ C greater than the range of lethal temperatures of reptiles. That the observed range is only about half of that predicted reaffirms our understanding of the importance of behavioral thermoregulation for these animals. Body size appears to limit the range of available Tb of ectotherms larger than 10 kg. The model is also used to calculate how much higher Tb could be than Ta for an animal exposed to high solar radiation and to low wind speed. For dry-skinned ectotherms, the difference increases about 4.5⚬ C for each 10-fold increase in body mass. For example, the maximum difference between Tb and Ta is 3⚬ C for a 10-6 kg ectotherm but 30⚬ C for a 1-kg ectotherm. Data from the literature generally support the quantitative predictions of the model. The size of a terrestrial ectotherm will determine which behavioral options are useful for controling Tb. Small insects (10 mg) cannot elevate Tb above Ta but they can control Tb by spatial movements. Ectotherms smaller than 1 kg can heat quickly to temperatures at which they can be active when the thermal environment is suitable for only short periods each day. When conditions are extreme these opportunists must retreat quickly. Because of their thermal inertia, ectotherms larger than 10 kg have a smaller range of body temperatures from which to choose. If the mean operative temperatures are appropriate, however, large ectotherms can use their thermal inertia to be active over longer time periods during the day and in more extreme environments for the same range of body temperature than can smaller animals.

@article{doi101086284330,
    author = "Stevenson, R. D.",
    title = "Body Size and Limits to the Daily Range of Body Temperature in Terrestrial Ectotherms",
    year = "1985",
    journal = "The American Naturalist",
    abstract = "A nonequilibrium heat-transfer model is used to calculate the extreme range of body temperatures available to ectotherms of different masses. At about 1 kg a transition occurs in the amplitudes imposed on a terrestrial ectotherm's potential range in body temperature by the daily cycling of the thermal environment. Animals smaller than 1 kg can choose a wide range of temperatures, whereas animals larger than 1 kg experience smaller ranges in Tb. The range in Tb that small insects experience is limited by the range in Ta, which, however, can be large in the boundary layer of perching surfaces. Data from the literature indicate that ectotherms in the range of sizes from 0.01 to 1 kg have limited ranges of Tb (about 30⚬ C). The model predicts that it could be as large as 55⚬ C, 15⚬ C greater than the range of lethal temperatures of reptiles. That the observed range is only about half of that predicted reaffirms our understanding of the importance of behavioral thermoregulation for these animals. Body size appears to limit the range of available Tb of ectotherms larger than 10 kg. The model is also used to calculate how much higher Tb could be than Ta for an animal exposed to high solar radiation and to low wind speed. For dry-skinned ectotherms, the difference increases about 4.5⚬ C for each 10-fold increase in body mass. For example, the maximum difference between Tb and Ta is 3⚬ C for a 10-6 kg ectotherm but 30⚬ C for a 1-kg ectotherm. Data from the literature generally support the quantitative predictions of the model. The size of a terrestrial ectotherm will determine which behavioral options are useful for controling Tb. Small insects (10 mg) cannot elevate Tb above Ta but they can control Tb by spatial movements. Ectotherms smaller than 1 kg can heat quickly to temperatures at which they can be active when the thermal environment is suitable for only short periods each day. When conditions are extreme these opportunists must retreat quickly. Because of their thermal inertia, ectotherms larger than 10 kg have a smaller range of body temperatures from which to choose. If the mean operative temperatures are appropriate, however, large ectotherms can use their thermal inertia to be active over longer time periods during the day and in more extreme environments for the same range of body temperature than can smaller animals.",
    url = "https://doi.org/10.1086/284330",
    doi = "10.1086/284330",
    openalex = "W2063920976",
    references = "doi1010079781468499179, doi101007bf00379617, doi1010160022519376900631, doi101016s0006349576857116, doi101038scientificamerican0459105, doi10106313128494, doi101126science18441401001, doi1023071934960, doi1023071936926, doi1023071937714, doi1023071948545, spotila1973a"
}

A series of simple heat-transfer models (termed the basic, conduction, physiological, and wet-skin models) is derived to examine a large number of behavioral and physiological mechanisms that are used by terrestrial ectotherms to control body temperature (Tb; table 1). The models reaffirm two generalizations: (1) in environments where solar radiation is available, behavioral mechanisms may provide a range of Tb's that is many times greater than the range in Tb's that results from physiological adjustments; and (2) among behavioral mechanisms, the times of seasonal and daily activity appear to be the most critical in determining Tb. Furthermore, microhabitat selection is more important than postural adjustments for controlling Tb. The models calculate Tb as the sum of air temperature (Ta) and the body-air temperature difference (Td). The direct effects of body size are expressed as functions of Td. Many behavioral mechanisms can then be expressed as some fraction of Td. The models (eqs. 3, 6, 8, 11), in combination with table 2 and the Smithsonian tables (List 1966), allow one to quickly estimate the effects of many environmental variables and behavioral and physiological mechanisms on Tb.

@article{doi101086284423,
    author = "Stevenson, R. D.",
    title = "The Relative Importance of Behavioral and Physiological Adjustments Controlling Body Temperature in Terrestrial Ectotherms",
    year = "1985",
    journal = "The American Naturalist",
    abstract = "A series of simple heat-transfer models (termed the basic, conduction, physiological, and wet-skin models) is derived to examine a large number of behavioral and physiological mechanisms that are used by terrestrial ectotherms to control body temperature (Tb; table 1). The models reaffirm two generalizations: (1) in environments where solar radiation is available, behavioral mechanisms may provide a range of Tb's that is many times greater than the range in Tb's that results from physiological adjustments; and (2) among behavioral mechanisms, the times of seasonal and daily activity appear to be the most critical in determining Tb. Furthermore, microhabitat selection is more important than postural adjustments for controlling Tb. The models calculate Tb as the sum of air temperature (Ta) and the body-air temperature difference (Td). The direct effects of body size are expressed as functions of Td. Many behavioral mechanisms can then be expressed as some fraction of Td. The models (eqs. 3, 6, 8, 11), in combination with table 2 and the Smithsonian tables (List 1966), allow one to quickly estimate the effects of many environmental variables and behavioral and physiological mechanisms on Tb.",
    url = "https://doi.org/10.1086/284423",
    doi = "10.1086/284423",
    openalex = "W2092101527",
    references = "doi1023071441115, doi1023071942256, openalexw2983381470"
}

Journal Article Interspecific allometry of population density in mammals and other animals: the independence of body mass and population energy-use Get access JOHN DAMUTH JOHN DAMUTH 1Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington D.C. 20560, U.S.A Search for other works by this author on: Oxford Academic Google Scholar Biological Journal of the Linnean Society, Volume 31, Issue 3, July 1987, Pages 193–246, https://doi.org/10.1111/j.1095-8312.1987.tb01990.x Published: 28 June 2008 Article history Received: 23 October 1986 Accepted: 30 January 1987 Published: 28 June 2008

@article{doi101111j109583121987tb01990x,
    author = "Damuth, John",
    title = "Interspecific allometry of population density in mammals and other animals: the independence of body mass and population energy-use",
    year = "1987",
    journal = "Biological Journal of the Linnean Society",
    abstract = "Journal Article Interspecific allometry of population density in mammals and other animals: the independence of body mass and population energy-use Get access JOHN DAMUTH JOHN DAMUTH 1Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington D.C. 20560, U.S.A Search for other works by this author on: Oxford Academic Google Scholar Biological Journal of the Linnean Society, Volume 31, Issue 3, July 1987, Pages 193–246, https://doi.org/10.1111/j.1095-8312.1987.tb01990.x Published: 28 June 2008 Article history Received: 23 October 1986 Accepted: 30 January 1987 Published: 28 June 2008",
    url = "https://doi.org/10.1111/j.1095-8312.1987.tb01990.x",
    doi = "10.1111/j.1095-8312.1987.tb01990.x",
    openalex = "W2152454003",
    references = "doi101086283547, doi101086284330, doi1023072937268"
}

We question the widespread assumption that body size and age are strongly correlated in adult amphibians and reptiles. Data for the smooth newt (Triturus vulgaris) suggest that growth rate prior to the age of first breeding is a much more significant source of variance in body size than age. A review of the data available for amphibians and reptiles suggests that this is true for the majority of species. Four methods for determining age are discussed and we conclude that only two of them, skeletochronology and mark-recapture, are reliable. We argue that female choice in anurans that favours larger males may not, as has frequently been suggested, mean that females mate with older males, but with males that have shown rapid juvenile growth. It is widely assumed that amphibians and reptiles show indeterminate growth and that body size and age are therefore posi- tively correlated (Duellman and Trueb, 1985). This assumption has formed the ba- sis of various evolutionary hypotheses, for example, that, if female anurans show a mating preference for larger males, they will mate with older males whose ability to survive a long time may have some her- itable basis (Howard, 1978; Halliday, 1983a, b; Duellman and Trueb, 1985). In this pa- per, we review the evidence that body size and age are correlated in adult amphibians and reptiles, critically evaluate four meth- ods that have been used to estimate age, and discuss the extent to which hypotheses that assume a size-age correlation are ten- able.

@article{doi1023071564148,
    author = "Halliday, Tim and Verrell, Paul A.",
    title = "Body Size and Age in Amphibians and Reptiles",
    year = "1988",
    journal = "Journal of Herpetology",
    abstract = "We question the widespread assumption that body size and age are strongly correlated in adult amphibians and reptiles. Data for the smooth newt (Triturus vulgaris) suggest that growth rate prior to the age of first breeding is a much more significant source of variance in body size than age. A review of the data available for amphibians and reptiles suggests that this is true for the majority of species. Four methods for determining age are discussed and we conclude that only two of them, skeletochronology and mark-recapture, are reliable. We argue that female choice in anurans that favours larger males may not, as has frequently been suggested, mean that females mate with older males, but with males that have shown rapid juvenile growth. It is widely assumed that amphibians and reptiles show indeterminate growth and that body size and age are therefore posi- tively correlated (Duellman and Trueb, 1985). This assumption has formed the ba- sis of various evolutionary hypotheses, for example, that, if female anurans show a mating preference for larger males, they will mate with older males whose ability to survive a long time may have some her- itable basis (Howard, 1978; Halliday, 1983a, b; Duellman and Trueb, 1985). In this pa- per, we review the evidence that body size and age are correlated in adult amphibians and reptiles, critically evaluate four meth- ods that have been used to estimate age, and discuss the extent to which hypotheses that assume a size-age correlation are ten- able.",
    url = "https://doi.org/10.2307/1564148",
    doi = "10.2307/1564148",
    openalex = "W1969955693",
    references = "doi101111j109636421961tb00220x, doi101139z79216"
}

Nocturnal geckos are active with body temperatures Tb that are low and variable relative to those of diurnal lizards. If the physiology of geckos is evolutionarily adapted to these low and variable Tb's, then the physiology of geckos should function best at relatively low and variable temperatures. We tested a specific prediction of this hypothesis by comparing the thermal dependence of sprint speed of nocturnal geckos versus diurnal lizards. In fact, optimal temperatures and performance breadths for sprinting of several geckos (Coleonyx brevis, C. variegatus, Hemidactylus frenatus, H. turcicus, Lepidodactylus lugubris) do not differ substantially from those of diurnal lizards from other families. As a result geckos normally forage at night at Tb that should be suboptimal for sprinting. Potential evolutionary explanations (e.g., evolutionary inertia of thermal physiology, possible selection pressures favoring high optimal temperatures) for the similarity of the thermal dependence of sprinting of geckos and diurnal lizards are evaluated.

@article{doi101086physzool62230156181,
    author = "Huey, Raymond B. and Niewiarowski, Peter H. and Kaufmann, Jefferey S. and Herron, Jon C.",
    title = "Thermal Biology of Nocturnal Ectotherms: Is Sprint Performance of Geckos Maximal at Low Body Temperatures?",
    year = "1989",
    journal = "Physiological Zoology",
    abstract = "Nocturnal geckos are active with body temperatures Tb that are low and variable relative to those of diurnal lizards. If the physiology of geckos is evolutionarily adapted to these low and variable Tb's, then the physiology of geckos should function best at relatively low and variable temperatures. We tested a specific prediction of this hypothesis by comparing the thermal dependence of sprint speed of nocturnal geckos versus diurnal lizards. In fact, optimal temperatures and performance breadths for sprinting of several geckos (Coleonyx brevis, C. variegatus, Hemidactylus frenatus, H. turcicus, Lepidodactylus lugubris) do not differ substantially from those of diurnal lizards from other families. As a result geckos normally forage at night at Tb that should be suboptimal for sprinting. Potential evolutionary explanations (e.g., evolutionary inertia of thermal physiology, possible selection pressures favoring high optimal temperatures) for the similarity of the thermal dependence of sprinting of geckos and diurnal lizards are evaluated.",
    url = "https://doi.org/10.1086/physzool.62.2.30156181",
    doi = "10.1086/physzool.62.2.30156181",
    openalex = "W2269390473",
    references = "werner1978observations"
}

Species distribution models (SDMs) are numerical tools that combine observations of species occurrence or abundance with environmental estimates. They are used to gain ecological and evolutionary insights and to predict distributions across landscapes,...Read More

@article{doi101146annureves20110189000525,
    author = "LaBarbera, Michael",
    title = "Analyzing Body Size as a Factor in Ecology and Evolution",
    year = "1989",
    journal = "Annual Review of Ecology and Systematics",
    abstract = "Species distribution models (SDMs) are numerical tools that combine observations of species occurrence or abundance with environmental estimates. They are used to gain ecological and evolutionary insights and to predict distributions across landscapes,...Read More",
    url = "https://doi.org/10.1146/annurev.es.20.110189.000525",
    doi = "10.1146/annurev.es.20.110189.000525",
    openalex = "W2162076213",
    references = "doi101086404940, doi101111j1469185x1966tb01624x, doi101111j155856461949tb00010x, doi101111j155856461973tb05912x, doi101139e83050, doi1023072412740, doi1023072527939"
}

Comparisons of size and body weight were made between common toads, Bufo bufo, from two geographically close (27 km) but separated populations (Portland; Purbeck) in Dorset, S. England between 1982 and 1985.Significant differences were found in the length and weight of males and females, both between years at each site and between sites and showed that the Purbeck toads were both heavier (23%) for any given body length and longer (17 %) than the Portland toads.Within a site, the between year variation in the body weight of toads of the same body length was such that the heaviest toads weighed up to 14% more than the lightest toads.The body length of toads at both sites were compared with those from common toad populations in Wales and Europe.

@article{doi101163156853890x00555,
    author = "Reading, C. J.",
    title = "A comparison of size and body weights of common toads (Bufo bufo) from two sites in Southern England",
    year = "1990",
    journal = "Amphibia-Reptilia",
    abstract = "Comparisons of size and body weight were made between common toads, Bufo bufo, from two geographically close (27 km) but separated populations (Portland; Purbeck) in Dorset, S. England between 1982 and 1985.Significant differences were found in the length and weight of males and females, both between years at each site and between sites and showed that the Purbeck toads were both heavier (23\%) for any given body length and longer (17 \%) than the Portland toads.Within a site, the between year variation in the body weight of toads of the same body length was such that the heaviest toads weighed up to 14\% more than the lightest toads.The body length of toads at both sites were compared with those from common toad populations in Wales and Europe.",
    url = "https://doi.org/10.1163/156853890x00555",
    doi = "10.1163/156853890x00555",
    openalex = "W1989531673",
    references = "busack1978body, doi101163156853888x00369, doi1023071933495, doi1023072403172, doi1023072422665, doi1023073544148, doi1023074281, openalexw1539737010, openalexw2242820788"
}

An investigation of the relationship between the onset of sexual maturity, age and body size in common toads Bufo bufo was started in 1984 at a pond in southern England. During the toad breeding seasons of 1984 and 1985, 7259 common toad‘metamorphs’were captured and permanently marked so that if captured as adults their true age would be known. Although a very small proportion of males and females reached sexual maturity at ages of two and four years respectively, most did so much later and asynchronously. The body size of toads breeding for the first time was relatively constant for each sex and not correlated with age. The rational behind our understanding of the mechanism of female choice is discussed in the light of these results.

@article{doi101111j160005871991tb00658x,
    author = "Reading, C. J.",
    title = "The relationship between body length, age and sexual maturity in the common toad, Bufo bufo",
    year = "1991",
    journal = "Ecography",
    abstract = "An investigation of the relationship between the onset of sexual maturity, age and body size in common toads Bufo bufo was started in 1984 at a pond in southern England. During the toad breeding seasons of 1984 and 1985, 7259 common toad‘metamorphs’were captured and permanently marked so that if captured as adults their true age would be known. Although a very small proportion of males and females reached sexual maturity at ages of two and four years respectively, most did so much later and asynchronously. The body size of toads breeding for the first time was relatively constant for each sex and not correlated with age. The rational behind our understanding of the mechanism of female choice is discussed in the light of these results.",
    url = "https://doi.org/10.1111/j.1600-0587.1991.tb00658.x",
    doi = "10.1111/j.1600-0587.1991.tb00658.x",
    openalex = "W2152639987",
    references = "doi101163156853890x00555"
}

@article{warwick1991observations,
    author = "Warwick, Clifford",
    title = "Observations on disease-associated preferred body temperatures in reptiles",
    year = "1991",
    journal = "Applied Animal Behaviour Science",
    url = "https://doi.org/10.1016/0168-1591(91)90169-x",
    doi = "10.1016/0168-1591(91)90169-x",
    number = "4",
    openalex = "W1970624967",
    pages = "375-380",
    volume = "28",
    references = "doi101002jez1402410118, doi101002jmor1051500212, doi101016016815919090082o, doi101093icb293935, doi101093icb293973, doi101111j109636421986tb00646x, doi1023071444765, doi1023071445010"
}

Average field body temperatures of pregnant female Podarcis muralis (32.620C) were significantly lower than that of males and non-pregnant females (overall average: 33.740C). However, when tested in terrarium with a strong thermal gradient in a limited space, which represents a low-cost environment for thermoregulation, neither body temperature nor position in the thermal gradient differed among groups of sex and reproductive condition. Body temperatures selected in thermal gradient (overall average: 33.770C) was similar to those exhibited in the field by males and nonpregnant females. This means that low body temperature exhibited by pregnant females in the field is not a consequence of a change of the thermal preferences at this stage, but might be explained on the basis of constraints related to their reproductive condition. Pregnant females stay closer to the refuge and allow approach to a shorter distance than do males and non-pregnant females. Approach distance was partially explained by the distance to refuge, but even when the effects of the distance to refuge were removed by applying the residuals of the regression, the approach distance for pregnant females was significantly lower than for other individuals. This reflects the existence of a behavioural component of motion-less in addition to the tendency to remain closer to a shelter, and means a shift in the predator-avoidance tactic from flight to crypsis, presumably because effectiveness of the flight tactic would be reduced during pregnancy. The behavioural changes associated with pregnancy may preclude careful thermoregulation, as this requires frequent movements

@article{doi1023073544807,
    author = "Braña, F. and Braña, F.",
    title = "Shifts in Body Temperature and Escape Behaviour of Female Podarcis muralis during Pregnancy",
    year = "1993",
    journal = "Oikos",
    abstract = "Average field body temperatures of pregnant female Podarcis muralis (32.620C) were significantly lower than that of males and non-pregnant females (overall average: 33.740C). However, when tested in terrarium with a strong thermal gradient in a limited space, which represents a low-cost environment for thermoregulation, neither body temperature nor position in the thermal gradient differed among groups of sex and reproductive condition. Body temperatures selected in thermal gradient (overall average: 33.770C) was similar to those exhibited in the field by males and nonpregnant females. This means that low body temperature exhibited by pregnant females in the field is not a consequence of a change of the thermal preferences at this stage, but might be explained on the basis of constraints related to their reproductive condition. Pregnant females stay closer to the refuge and allow approach to a shorter distance than do males and non-pregnant females. Approach distance was partially explained by the distance to refuge, but even when the effects of the distance to refuge were removed by applying the residuals of the regression, the approach distance for pregnant females was significantly lower than for other individuals. This reflects the existence of a behavioural component of motion-less in addition to the tendency to remain closer to a shelter, and means a shift in the predator-avoidance tactic from flight to crypsis, presumably because effectiveness of the flight tactic would be reduced during pregnancy. The behavioural changes associated with pregnancy may preclude careful thermoregulation, as this requires frequent movements",
    url = "https://doi.org/10.2307/3544807",
    doi = "10.2307/3544807",
    openalex = "W2326841672",
    references = "openalexw2478193195"
}

Abstract This paper summarises evidence for low rates of annual reproductive output (no. of offspring or eggs/female/yr) in New Zealand reptiles. Tuatara (Sphenodon spp.) and the geckos Hoplodactylus maculatus and H. duvaucelii are cold‐adapted, nocturnal, and long‐lived, with evidence in at least some populations of less‐than‐annual reproduction. Annual reproductive output estimated for three tuatara populations ranges from 1.27 to 2.28 eggs/ female/yr. New Zealand geckos produce ≤2 offspring/female/yr. Hoplodactylus maculatus in the Macraes‐Middlemarch region of Central Otago produces only about 0.85 offspring/female/yr, as a consequence of biennial reproduction and clutch sizes that are often less than two. The diurnal skinks Leiolopisma grande and L. otagense from the same region breed annually and have larger clutch sizes, so their annual reproductive output is higher (2.17 and 2.34 offspring/female/yr, respectively). Other wild populations of New Zealand skinks typically produce 1–5 offspring/female/yr. Unlike many species of oviparous geckos overseas, the viviparous New Zealand geckos do not produce multiple clutches per year, and this contributes to relatively low annual reproductive output in some species. Viviparous New Zealand skinks have similar annual reproductive output to viviparous skinks of similar body size from other parts of the world. Low annual reproductive output in New Zealand lizards thus appears to reflect, in part, responses to cool summer temperatures in association with a viviparous reproductive mode (geckos), as well as phylogenetic effects (colonisation by lineages of small clutch and body size, in geckos and skinks).

@article{doi1010800301422319949518005,
    author = "Cree, Alison",
    title = "Low annual reproductive output in female reptiles from New Zealand",
    year = "1994",
    journal = "New Zealand Journal of Zoology",
    abstract = "Abstract This paper summarises evidence for low rates of annual reproductive output (no. of offspring or eggs/female/yr) in New Zealand reptiles. Tuatara (Sphenodon spp.) and the geckos Hoplodactylus maculatus and H. duvaucelii are cold‐adapted, nocturnal, and long‐lived, with evidence in at least some populations of less‐than‐annual reproduction. Annual reproductive output estimated for three tuatara populations ranges from 1.27 to 2.28 eggs/ female/yr. New Zealand geckos produce ≤2 offspring/female/yr. Hoplodactylus maculatus in the Macraes‐Middlemarch region of Central Otago produces only about 0.85 offspring/female/yr, as a consequence of biennial reproduction and clutch sizes that are often less than two. The diurnal skinks Leiolopisma grande and L. otagense from the same region breed annually and have larger clutch sizes, so their annual reproductive output is higher (2.17 and 2.34 offspring/female/yr, respectively). Other wild populations of New Zealand skinks typically produce 1–5 offspring/female/yr. Unlike many species of oviparous geckos overseas, the viviparous New Zealand geckos do not produce multiple clutches per year, and this contributes to relatively low annual reproductive output in some species. Viviparous New Zealand skinks have similar annual reproductive output to viviparous skinks of similar body size from other parts of the world. Low annual reproductive output in New Zealand lizards thus appears to reflect, in part, responses to cool summer temperatures in association with a viviparous reproductive mode (geckos), as well as phylogenetic effects (colonisation by lineages of small clutch and body size, in geckos and skinks).",
    url = "https://doi.org/10.1080/03014223.1994.9518005",
    doi = "10.1080/03014223.1994.9518005",
    openalex = "W2008819460",
    references = "werner1978observations"
}

We monitored meteorological variables, daily and seasonal patterns of body temperature, corresponding operative temperatures, and microhabitat utilization by desert tortoises (Gopherus agassizii) during the 1991 and 1992 activity seasons of tortoises in the eastern Mojave desert.We studied tortoises in enclosures of natural habitat at the Desert Tortoise Conservation Center (DTCC) near Las Vegas, Nevada and a population of free-ranging tortoises in a field site adjacent to the DTCC.Air, ground and operative temperatures coincided with daily and monthly patterns of incident solar radiation.Variation in body temperature was primarily a consequence of microhabitat selection, principally use of burrows.During July-October, in the morning, body temperatures of tortoises in burrows were cooler than those of individuals on the surface.During midday, tortoises remained in burrows where body temperatures were cooler than extreme surface operative temperatures.While tortoises remained in burrows during much of the day, tortoises typically did not sleep in burrows at night.Microhabitat utilization was dictated by avoidance of extreme temperatures during midday, and microhabitat selection corresponded qualitatively to maintenance of energy and water balances.Effective conservation efforts to preserve habitat of desert tortoises will focus upon managing variables associated with integrity of burrows.

@article{doi1023071467069,
    author = "Zimmerman, Linda C. and O′Connor, Michael and Bulova, Susan J. and Spotila, James R. and Kemp, Stanley J. and Salice, Christopher J.",
    title = "Thermal Ecology of Desert Tortoises in the Eastern Mojave Desert: Seasonal Patterns of Operative and Body Temperatures, and Microhabitat Utilization",
    year = "1994",
    journal = "Herpetological Monographs",
    abstract = "We monitored meteorological variables, daily and seasonal patterns of body temperature, corresponding operative temperatures, and microhabitat utilization by desert tortoises (Gopherus agassizii) during the 1991 and 1992 activity seasons of tortoises in the eastern Mojave desert.We studied tortoises in enclosures of natural habitat at the Desert Tortoise Conservation Center (DTCC) near Las Vegas, Nevada and a population of free-ranging tortoises in a field site adjacent to the DTCC.Air, ground and operative temperatures coincided with daily and monthly patterns of incident solar radiation.Variation in body temperature was primarily a consequence of microhabitat selection, principally use of burrows.During July-October, in the morning, body temperatures of tortoises in burrows were cooler than those of individuals on the surface.During midday, tortoises remained in burrows where body temperatures were cooler than extreme surface operative temperatures.While tortoises remained in burrows during much of the day, tortoises typically did not sleep in burrows at night.Microhabitat utilization was dictated by avoidance of extreme temperatures during midday, and microhabitat selection corresponded qualitatively to maintenance of energy and water balances.Effective conservation efforts to preserve habitat of desert tortoises will focus upon managing variables associated with integrity of burrows.",
    url = "https://doi.org/10.2307/1467069",
    doi = "10.2307/1467069",
    openalex = "W4235602676",
    references = "doi1010160010406x7090592x"
}

Abstract We compared the escape behaviour of juvenile and adult Psammodromus algirus lizards, by using data of escape performance in the laboratory and field observations of escape behaviour. We specifically examined whether a differential escape response is a constraint of body size, or whether juveniles behave differently in order to maximize their escape possibilities taking into account their size-related speed limitations. In the laboratory, juvenile lizards were slower than adult lizards, and escaped during less time and to shorter distances, even when removing the effect of body size. In the field, juveniles allowed closer approaches and after a short flight usually did not hide immediately, but did so after successive short runs if the attack persists. Approach distance of juveniles was not affected by habitat, but initial and total flight distances were shorter in covered microhabitats. There was no significant effect of environmental temperature on approach and initial flight distances of juveniles. However, the total flight distances were significantly correlated with air temperatures.

@article{doi101163156853995x00685,
    author = "Martı́n, José and López, Pílar",
    title = "Escape Behaviour of Juvenile Psammodromus Algirus Lizards: Constraint of or Compensation for Limitations in Body Size?",
    year = "1995",
    journal = "Behaviour",
    abstract = "Abstract We compared the escape behaviour of juvenile and adult Psammodromus algirus lizards, by using data of escape performance in the laboratory and field observations of escape behaviour. We specifically examined whether a differential escape response is a constraint of body size, or whether juveniles behave differently in order to maximize their escape possibilities taking into account their size-related speed limitations. In the laboratory, juvenile lizards were slower than adult lizards, and escaped during less time and to shorter distances, even when removing the effect of body size. In the field, juveniles allowed closer approaches and after a short flight usually did not hide immediately, but did so after successive short runs if the attack persists. Approach distance of juveniles was not affected by habitat, but initial and total flight distances were shorter in covered microhabitats. There was no significant effect of environmental temperature on approach and initial flight distances of juveniles. However, the total flight distances were significantly correlated with air temperatures.",
    url = "https://doi.org/10.1163/156853995x00685",
    doi = "10.1163/156853995x00685",
    openalex = "W2085300178",
    references = "doi101111j160005871989tb00832x"
}

Body size is often assumed to represent the outcome of conflicting selection pressures of natural and sexual selection. Marine iguana (Amblyrhynchus cristatus) populations in the Galápagos exhibit 10-fold differences in body mass between island populations. There is also strong sexual size dimorphism, with males being about twice as heavy as females. To understand the evolutionary processes shaping body size in marine iguanas, we analyzed the selection differentials on body size in two island populations (max. male mass 900 g in Genovesa, 3500 g in Santa Fé). Factors that usually confound any evolutionary analysis of body sizes-predation, interspecific food competition, reproductive role division-are ruled out for marine iguanas. We show that, above hatchlings, mortality rates increased with body size in both sexes to the same extent. This effect was independent of individual age. The largest animals (males) of each island were the first to die once environmental conditions deteriorated (e.g., during El Niños). This sex-biased mortality was the result of sexual size dimorphism, but at the same time caused sexual size dimorphism to fluctuate. Mortality differed between seasons (selection differentials as low as -1.4) and acted on different absolute body sizes between islands. Both males and females did not cease growth when an optimal body size for survival was reached, as demonstrated by the fact that individual adult body size phenotypically increased in each population under favorable environmental conditions beyond naturally selected limits. But why did marine iguanas grow "too large" for survival? Due to lek mating, sexual selection constantly favored large body size in males (selection differentials up to +0.77). Females only need to reach a body size sufficient to produce surviving offspring. Thereafter, large body size of females was less favored by fertility selection than large size in males. Resulting from these different selection pressures on male and female size, sexual size dimorphism was mechanistically caused by the fact that females matured at an earlier age and size than males, whereafter they constantly allocated resources into eggs, which slowed growth. The observed allometric increase in sexual size dimorphism is explained by the fact that the difference between these selective processes becomes larger as energy abundance in the environment increases. Because body size is generally highly heritable, these selective processes are expected to lead to genetic differences in body size between islands. We propose a common-garden experiment to determine the influence of genetic factors and phenotypic reaction norms of final body size.

@article{doi1023072411166,
    author = "Wikelski, Martin and Trillmich, Fritz",
    title = "Body Size and Sexual Size Dimorphism in Marine Iguanas Fluctuate as a Result of Opposing Natural and Sexual Selection: An Island Comparison",
    year = "1997",
    journal = "Evolution",
    abstract = {Body size is often assumed to represent the outcome of conflicting selection pressures of natural and sexual selection. Marine iguana (Amblyrhynchus cristatus) populations in the Galápagos exhibit 10-fold differences in body mass between island populations. There is also strong sexual size dimorphism, with males being about twice as heavy as females. To understand the evolutionary processes shaping body size in marine iguanas, we analyzed the selection differentials on body size in two island populations (max. male mass 900 g in Genovesa, 3500 g in Santa Fé). Factors that usually confound any evolutionary analysis of body sizes-predation, interspecific food competition, reproductive role division-are ruled out for marine iguanas. We show that, above hatchlings, mortality rates increased with body size in both sexes to the same extent. This effect was independent of individual age. The largest animals (males) of each island were the first to die once environmental conditions deteriorated (e.g., during El Niños). This sex-biased mortality was the result of sexual size dimorphism, but at the same time caused sexual size dimorphism to fluctuate. Mortality differed between seasons (selection differentials as low as -1.4) and acted on different absolute body sizes between islands. Both males and females did not cease growth when an optimal body size for survival was reached, as demonstrated by the fact that individual adult body size phenotypically increased in each population under favorable environmental conditions beyond naturally selected limits. But why did marine iguanas grow "too large" for survival? Due to lek mating, sexual selection constantly favored large body size in males (selection differentials up to +0.77). Females only need to reach a body size sufficient to produce surviving offspring. Thereafter, large body size of females was less favored by fertility selection than large size in males. Resulting from these different selection pressures on male and female size, sexual size dimorphism was mechanistically caused by the fact that females matured at an earlier age and size than males, whereafter they constantly allocated resources into eggs, which slowed growth. The observed allometric increase in sexual size dimorphism is explained by the fact that the difference between these selective processes becomes larger as energy abundance in the environment increases. Because body size is generally highly heritable, these selective processes are expected to lead to genetic differences in body size between islands. We propose a common-garden experiment to determine the influence of genetic factors and phenotypic reaction norms of final body size.},
    url = "https://doi.org/10.2307/2411166",
    doi = "10.2307/2411166",
    openalex = "W2088796601",
    references = "doi1010160010406x65903208"
}

@article{doi10103827376,
    author = "Friedman, Jeffrey M. and Halaas, Jeffrey L.",
    title = "Leptin and the regulation of body weight in mammals",
    year = "1998",
    journal = "Nature",
    url = "https://doi.org/10.1038/27376",
    doi = "10.1038/27376",
    openalex = "W1631449371"
}

@misc{crossref1999biomathematics,
    title = "Biomathematics",
    year = "1999",
    url = "https://doi.org/10.1016/b978-0-444-50273-5.x5025-3",
    doi = "10.1016/b978-0-444-50273-5.x5025-3"
}

We discuss three aspects of the thermal biology of lacertid lizards. First, we provide an overview of the available data on field body temperatures (Tb), the thermal sensitivity of various performance functions and selected body temperatures in different species of lacertid lizards. We also briefly summarise information on the mechanisms of thermoregulation. Second, we discuss recent developments to estimate the »precision« of thermoregulation, and the contribution of distinct behavioural mechanisms. Finally, we revise available evidence for the existence of evolutionary adjustments of thermal characteristics in lacertid lizards. Existing studies have mainly dealt with within- and among-species differences in thermoregulatory behaviour (selected temperatures) and thermal physiology of adults (optimal temperatures, heating rates). Available data provide only limited evidence for clear-cut evolutionary shifts in thermal physiology characteristics along climatic gradients.

@article{openalexw602451413,
    author = "Castilla, Aurora M. and Damme, Raoul Van and Bauwens, Dirk",
    title = "Field body temperatures, mechanisms of thermoregulation and evolution of thermal characteristics in lacertid lizards",
    year = "1999",
    journal = "University of Zagreb University Computing Centre (SRCE)",
    abstract = "We discuss three aspects of the thermal biology of lacertid lizards. First, we provide an overview of the available data on field body temperatures (Tb), the thermal sensitivity of various performance functions and selected body temperatures in different species of lacertid lizards. We also briefly summarise information on the mechanisms of thermoregulation. Second, we discuss recent developments to estimate the »precision« of thermoregulation, and the contribution of distinct behavioural mechanisms. Finally, we revise available evidence for the existence of evolutionary adjustments of thermal characteristics in lacertid lizards. Existing studies have mainly dealt with within- and among-species differences in thermoregulatory behaviour (selected temperatures) and thermal physiology of adults (optimal temperatures, heating rates). Available data provide only limited evidence for clear-cut evolutionary shifts in thermal physiology characteristics along climatic gradients.",
    openalex = "W602451413",
    references = "doi101111j160005871989tb00832x, openalexw2478193195, warwick1991observations"
}

Complex organismal traits such as body size are influenced by innumerable selective pressures, making the prediction of evolutionary trajectories for those traits difficult. A potentially powerful way to predict fitness in natural systems is to study the composite response of individuals in terms of performance measures, such as foraging or reproductive performance. Once key performance measures are identified in this top-down approach, we can determine the underlying physiological mechanisms and gain predictive power over long-term evolutionary processes. Here we use marine iguanas as a model system where body size differs by more than one order of magnitude between island populations. We identified foraging efficiency as the main performance measure that constrains body size. Mechanistically, foraging performance is determined by food pasture height and the thermal environment, influencing intake and digestion. Stress hormones may be a flexible way of influencing an individual's response to low-food situations that may be caused by high population density, famines, or anthropogenic disturbances like oil spills. Reproductive performance, on the other hand, increases with body size and is mediated by higher survival of larger hatchlings from larger females and increased mating success of larger males. Reproductive performance of males may be adjusted via plastic hormonal feedback mechanisms that allow individuals to assess their social rank annually within the current population size structure. When integrated, these data suggest that reproductive performance favors increased body size (influenced by reproductive hormones), with an overall limit imposed by foraging performance (influenced by stress hormones). Based on our mechanistic understanding of individual performances we predicted an evolutionary increase in maximum body size caused by global warming trends. We support this prediction using specimens collected during 1905. We also show in a common-garden experiment that body size may have a genetic component in iguanids. This 'performance paradigm' allows predictions about adaptive evolution in natural populations.

@article{doi101093icb433376,
    author = "Wikelski, Martin",
    title = "Body Size, Performance and Fitness in Galapagos Marine Iguanas",
    year = "2003",
    journal = "Integrative and Comparative Biology",
    abstract = "Complex organismal traits such as body size are influenced by innumerable selective pressures, making the prediction of evolutionary trajectories for those traits difficult. A potentially powerful way to predict fitness in natural systems is to study the composite response of individuals in terms of performance measures, such as foraging or reproductive performance. Once key performance measures are identified in this top-down approach, we can determine the underlying physiological mechanisms and gain predictive power over long-term evolutionary processes. Here we use marine iguanas as a model system where body size differs by more than one order of magnitude between island populations. We identified foraging efficiency as the main performance measure that constrains body size. Mechanistically, foraging performance is determined by food pasture height and the thermal environment, influencing intake and digestion. Stress hormones may be a flexible way of influencing an individual's response to low-food situations that may be caused by high population density, famines, or anthropogenic disturbances like oil spills. Reproductive performance, on the other hand, increases with body size and is mediated by higher survival of larger hatchlings from larger females and increased mating success of larger males. Reproductive performance of males may be adjusted via plastic hormonal feedback mechanisms that allow individuals to assess their social rank annually within the current population size structure. When integrated, these data suggest that reproductive performance favors increased body size (influenced by reproductive hormones), with an overall limit imposed by foraging performance (influenced by stress hormones). Based on our mechanistic understanding of individual performances we predicted an evolutionary increase in maximum body size caused by global warming trends. We support this prediction using specimens collected during 1905. We also show in a common-garden experiment that body size may have a genetic component in iguanids. This 'performance paradigm' allows predictions about adaptive evolution in natural populations.",
    url = "https://doi.org/10.1093/icb/43.3.376",
    doi = "10.1093/icb/43.3.376",
    openalex = "W2124767268",
    references = "doi1010160010406x65903208"
}

The majority of ectotherms grow slower but mature at a larger body size in colder environments. This phenomenon has puzzled biologists because classic theories of life-history evolution predict smaller sizes at maturity in environments that retard growth. During the last decade, intensive theoretical and empirical research has generated some plausible explanations based on nonadaptive or adaptive plasticity. Nonadaptive plasticity of body size is hypothesized to result from thermal constraints on cellular growth that cause smaller cells at higher temperatures, but the generality of this theory is poorly supported. Adaptive plasticity is hypothesized to result from greater benefits or lesser costs of delayed maturation in colder environments. These theories seem to apply well to some species but not others. Thus, no single theory has been able to explain the generality of temperature-size relationships in ectotherms. We recommend a multivariate theory that focuses on the coevolution of thermal reaction norms for growth rate and size at maturity. Such a theory should incorporate functional constraints on thermal reaction norms, as well as the natural covariation between temperature and other environmental variables.

@article{doi101093icb446498,
    author = "Angilletta, Michael J.",
    title = "Temperature, Growth Rate, and Body Size in Ectotherms: Fitting Pieces of a Life-History Puzzle",
    year = "2004",
    journal = "Integrative and Comparative Biology",
    abstract = "The majority of ectotherms grow slower but mature at a larger body size in colder environments. This phenomenon has puzzled biologists because classic theories of life-history evolution predict smaller sizes at maturity in environments that retard growth. During the last decade, intensive theoretical and empirical research has generated some plausible explanations based on nonadaptive or adaptive plasticity. Nonadaptive plasticity of body size is hypothesized to result from thermal constraints on cellular growth that cause smaller cells at higher temperatures, but the generality of this theory is poorly supported. Adaptive plasticity is hypothesized to result from greater benefits or lesser costs of delayed maturation in colder environments. These theories seem to apply well to some species but not others. Thus, no single theory has been able to explain the generality of temperature-size relationships in ectotherms. We recommend a multivariate theory that focuses on the coevolution of thermal reaction norms for growth rate and size at maturity. Such a theory should incorporate functional constraints on thermal reaction norms, as well as the natural covariation between temperature and other environmental variables.",
    url = "https://doi.org/10.1093/icb/44.6.498",
    doi = "10.1093/icb/44.6.498",
    openalex = "W2178685873",
    references = "doi101016s0065250408602123, doi101016s0169534797010586, doi101016s0306456501000948"
}

Since the end of the 1980s there has been increasing evidence of worldwide amphibian declines in high-altitude regions. Moreover, amphibian conservation has so far mostly neglected the terrestrial habitat, which is essential for effective protection measures. We determined the location and quality of terrestrial habitats of common toads (Bufo bufo L., 1758) in a naturally fragmented alpine environment (Schlumsee, 1105 m a.s.l., Northern Calcareous Alps, Austria) characterized by a high diversity of available microhabitats. By radio-tracking 18 individuals during their post-spawning migration, we located terrestrial habitats 130–1000 m horizontally away from and 85–390 m above the breeding site. This is the first study to show vertical migration over several hundred metres in adult amphibians. Both adult and juvenile toads completed the migration within 2–7 weeks and, on their way to the summer habitat, climbed 45° scree slopes and ascended cliffs with slopes of up to 65°. Body condition indices were highest for individuals originating from the terrestrial summer habitat at the highest elevation, which is characterized by the highest vegetation diversity, a high abundance of food, and the highest insolation, probably allowing the toads to extend their activity period for food intake. Our study suggests that under demanding climatic conditions it can pay off for toads to undertake costly migrations to reach high-quality habitats. For amphibian conservation, high-value habitat patches need to be located and investigated to increase the effectiveness of protection measures.

@article{doi101139z05071,
    author = "Sztatecsny, Marc and Schabetsberger, Robert",
    title = "Into thin air: vertical migration, body condition, and quality of terrestrial habitats of alpine common toads, Bufo bufo",
    year = "2005",
    journal = "Canadian Journal of Zoology",
    abstract = "Since the end of the 1980s there has been increasing evidence of worldwide amphibian declines in high-altitude regions. Moreover, amphibian conservation has so far mostly neglected the terrestrial habitat, which is essential for effective protection measures. We determined the location and quality of terrestrial habitats of common toads (Bufo bufo L., 1758) in a naturally fragmented alpine environment (Schlumsee, 1105 m a.s.l., Northern Calcareous Alps, Austria) characterized by a high diversity of available microhabitats. By radio-tracking 18 individuals during their post-spawning migration, we located terrestrial habitats 130–1000 m horizontally away from and 85–390 m above the breeding site. This is the first study to show vertical migration over several hundred metres in adult amphibians. Both adult and juvenile toads completed the migration within 2–7 weeks and, on their way to the summer habitat, climbed 45° scree slopes and ascended cliffs with slopes of up to 65°. Body condition indices were highest for individuals originating from the terrestrial summer habitat at the highest elevation, which is characterized by the highest vegetation diversity, a high abundance of food, and the highest insolation, probably allowing the toads to extend their activity period for food intake. Our study suggests that under demanding climatic conditions it can pay off for toads to undertake costly migrations to reach high-quality habitats. For amphibian conservation, high-value habitat patches need to be located and investigated to increase the effectiveness of protection measures.",
    url = "https://doi.org/10.1139/z05-071",
    doi = "10.1139/z05-071",
    openalex = "W2000942048",
    references = "doi101163156853890x00555"
}

▪ Abstract Two consequences of terrestrial ectothermy (low energy needs and behavioral control of body temperatures) have had major consequences for the evolution of reptile life-history traits. For example, reproducing females can manipulate incubation temperatures and thus phenotypic traits of their offspring by retaining developing eggs in utero. This ability has resulted in multiple evolutionary transitions from oviparity to viviparity in cool-climate reptile populations. The spatial and temporal heterogeneity of operative temperatures in terrestrial habitats also has favored careful nest-site selection and a matching of embryonic reaction norms to thermal regimes during incubation (e.g., via temperature-dependent sex determination). Many of the life-history features in which reptiles differ from endothermic vertebrates—such as their small offspring sizes, large litter sizes, and infrequent reproduction—are direct consequences of ectothermy, reflecting freedom from heat-conserving constraints on body size and energy storage. Ectothermy confers immense flexibility, enabling a dynamic matching of life-history traits to local circumstances. This flexibility has generated massive spatial and temporal variation in life-history traits via phenotypic plasticity as well as adaptation. The diversity of life histories in reptiles can best be interpreted within a conceptual framework that views reptiles as low-energy, variable-temperature systems.

@article{doi101146annurevecolsys36102003152631,
    author = "Shine, Richard",
    title = "Life-History Evolution in Reptiles",
    year = "2005",
    journal = "Annual Review of Ecology Evolution and Systematics",
    abstract = "▪ Abstract Two consequences of terrestrial ectothermy (low energy needs and behavioral control of body temperatures) have had major consequences for the evolution of reptile life-history traits. For example, reproducing females can manipulate incubation temperatures and thus phenotypic traits of their offspring by retaining developing eggs in utero. This ability has resulted in multiple evolutionary transitions from oviparity to viviparity in cool-climate reptile populations. The spatial and temporal heterogeneity of operative temperatures in terrestrial habitats also has favored careful nest-site selection and a matching of embryonic reaction norms to thermal regimes during incubation (e.g., via temperature-dependent sex determination). Many of the life-history features in which reptiles differ from endothermic vertebrates—such as their small offspring sizes, large litter sizes, and infrequent reproduction—are direct consequences of ectothermy, reflecting freedom from heat-conserving constraints on body size and energy storage. Ectothermy confers immense flexibility, enabling a dynamic matching of life-history traits to local circumstances. This flexibility has generated massive spatial and temporal variation in life-history traits via phenotypic plasticity as well as adaptation. The diversity of life histories in reptiles can best be interpreted within a conceptual framework that views reptiles as low-energy, variable-temperature systems.",
    url = "https://doi.org/10.1146/annurev.ecolsys.36.102003.152631",
    doi = "10.1146/annurev.ecolsys.36.102003.152631",
    openalex = "W2136938707",
    references = "doi101007bf00344996, doi101007bf00346972, doi101086283547, doi101086285141, doi101086409470, doi101086410622, doi101098rspb19970181, doi1023071445695, doi1023073545800, doi10560219780801847806, openalexw1488067709, openalexw1525648878"
}

Agricultural land use may indirectly affect the body size of amphibians by altering the hydroperiods of nearby wetlands and influencing amphibian densities—both factors which can limit the larval and postmetamorphic growth rates of amphibians. We measured postmetamorphic body size for 4 species (Spea multiplicata, S. bombifrons, Bufo cognatus, Ambystoma tigrinum mavortium) and 3 age classes (metamorph, subadult, adult) of amphibians captured at playa wetlands surrounded by one of 2 general land-use types (cultivation, grassland) in the Southern High Plains. Sixteen playas (4 per land-use type in 1999 and 2000) were partially enclosed with drift fence and pitfall traps, and mass and snout-vent length (SVL) were measured from a subsample of captured individuals. Mass and SVL were 10–148% greater for amphibians captured at grassland wetlands than at cropland wetlands for most species and age classes. Mass and SVL also were 3–124% greater in 1999 than in 2000 for most species and age classes. We attribute differences in body size between land-use types to differences in the hydroperiods of the associated wetlands, and potentially to variation in the density of terrestrial conspecifics and aquatic predators. We attribute differences in body size between years to differences in rainfall. Body size is positively related to the probability of survival, reproduction, and evolutionary fitness in amphibians. Thus, if cultivation of landscapes surrounding wetlands negatively influences postmetamorphic body size of amphibians, restoration of native grasslands surrounding playa wetlands may help prevent local amphibian declines.

@article{doi1021930022541x20050690515ioluop20co2,
    author = "Gray, Matthew J. and Smith, Loren M.",
    title = "INFLUENCE OF LAND USE ON POSTMETAMORPHIC BODY SIZE OF PLAYA LAKE AMPHIBIANS",
    year = "2005",
    journal = "Journal of Wildlife Management",
    abstract = "Agricultural land use may indirectly affect the body size of amphibians by altering the hydroperiods of nearby wetlands and influencing amphibian densities—both factors which can limit the larval and postmetamorphic growth rates of amphibians. We measured postmetamorphic body size for 4 species (Spea multiplicata, S. bombifrons, Bufo cognatus, Ambystoma tigrinum mavortium) and 3 age classes (metamorph, subadult, adult) of amphibians captured at playa wetlands surrounded by one of 2 general land-use types (cultivation, grassland) in the Southern High Plains. Sixteen playas (4 per land-use type in 1999 and 2000) were partially enclosed with drift fence and pitfall traps, and mass and snout-vent length (SVL) were measured from a subsample of captured individuals. Mass and SVL were 10–148\% greater for amphibians captured at grassland wetlands than at cropland wetlands for most species and age classes. Mass and SVL also were 3–124\% greater in 1999 than in 2000 for most species and age classes. We attribute differences in body size between land-use types to differences in the hydroperiods of the associated wetlands, and potentially to variation in the density of terrestrial conspecifics and aquatic predators. We attribute differences in body size between years to differences in rainfall. Body size is positively related to the probability of survival, reproduction, and evolutionary fitness in amphibians. Thus, if cultivation of landscapes surrounding wetlands negatively influences postmetamorphic body size of amphibians, restoration of native grasslands surrounding playa wetlands may help prevent local amphibian declines.",
    url = "https://doi.org/10.2193/0022-541x(2005)069[0515:ioluop]2.0.co;2",
    doi = "10.2193/0022-541x(2005)069[0515:ioluop]2.0.co;2",
    openalex = "W2174163910",
    references = "doi101163156853890x00555"
}

Ontogenetic changes in color and pattern that are not directly related to reproduction are very common yet remain a poorly understood phenomenon. One example is conspicuous colors in the tails of fish, amphibians, and reptiles that fade out later in life. We suggest a novel hypothesis: conspicuous tail colors that appear only in juveniles compensate for an increased activity level, deflecting imminent attacks to the tail. We observed blue-tailed, newly hatched lizards (Acanthodactylus beershebensis) in the field and compared 5 behavioral parameters with those of older individuals that had already lost their neonate coloration. In addition, we explored whether tail displays, often assumed to direct a predator's attention to the tail, disappear with the color change. Striped blue-tailed hatchlings foraged more actively than 3-week-old juveniles, spent a longer time in open microhabitats, and performed deflective tail displays. In comparison, 2 other lacertids that do not undergo ontogenetic change did not switch to safer foraging when growing up. The results suggest that activity alteration may be a major factor affecting the ontogenetic color and pattern change. Active lizards that forage in open habitats increase their probability of attack by ambush predators. Conspicuous colors and deflection displays may shift attacks to the expendable tail, increasing the prey's overall probability of surviving attacks. The persistence of both striped body pattern and blue tail fits the active foraging period of neonates and hence may be appropriate for other species that display a conspicuous tail accompanied by a striped pattern.

@article{doi101093behecoarl023,
    author = "Hawlena, Dror and Boochnik, Rami and Abramsky, Zvika and Bouskila, Amos",
    title = "Blue tail and striped body: why do lizards change their infant costume when growing up?",
    year = "2006",
    journal = "Behavioral Ecology",
    abstract = "Ontogenetic changes in color and pattern that are not directly related to reproduction are very common yet remain a poorly understood phenomenon. One example is conspicuous colors in the tails of fish, amphibians, and reptiles that fade out later in life. We suggest a novel hypothesis: conspicuous tail colors that appear only in juveniles compensate for an increased activity level, deflecting imminent attacks to the tail. We observed blue-tailed, newly hatched lizards (Acanthodactylus beershebensis) in the field and compared 5 behavioral parameters with those of older individuals that had already lost their neonate coloration. In addition, we explored whether tail displays, often assumed to direct a predator's attention to the tail, disappear with the color change. Striped blue-tailed hatchlings foraged more actively than 3-week-old juveniles, spent a longer time in open microhabitats, and performed deflective tail displays. In comparison, 2 other lacertids that do not undergo ontogenetic change did not switch to safer foraging when growing up. The results suggest that activity alteration may be a major factor affecting the ontogenetic color and pattern change. Active lizards that forage in open habitats increase their probability of attack by ambush predators. Conspicuous colors and deflection displays may shift attacks to the expendable tail, increasing the prey's overall probability of surviving attacks. The persistence of both striped body pattern and blue tail fits the active foraging period of neonates and hence may be appropriate for other species that display a conspicuous tail accompanied by a striped pattern.",
    url = "https://doi.org/10.1093/beheco/arl023",
    doi = "10.1093/beheco/arl023",
    openalex = "W2135935675",
    references = "doi10108000222938400770131"
}

@misc{misra2006biomathematics,
    author = "Misra, J C",
    title = "Biomathematics",
    year = "2006",
    url = "https://doi.org/10.1142/5058",
    doi = "10.1142/5058"
}

ABSTRACT Aim To describe broad‐scale geographical patterns of body size for European and North American amphibian faunas and to explore possible processes underlying these patterns. Specifically, we propose a heat balance hypothesis, as both heat conservation and heat gain determine the heat balance of ectotherms, and test it along with five other hypotheses that have a possible influence on body size gradients: size dependence, migration ability, primary productivity, seasonality and water availability. Location Western Europe and North America north of Mexico. Methods We processed distribution maps for native amphibian species to estimate the mean body size in 110 × 110 km cells and calculated eight environmental predictors to explore the relationship between environmental gradients and the observed patterns. We used least squares regression modelling and model selection approaches based on information theory to evaluate the relative support for each hypothesis. Results We found consistent body size gradients and similar relationships to environmental variables within each amphibian group in Europe and North America. Annual potential evapotranspiration, a measure of environmental energy, was the strongest predictor of mean body size in both regions. However, the contrasting responses to ambient energy in each group resulted in opposite geographical patterns, i.e. anurans increased in size from high‐ to low‐energy areas in both continents and urodeles showed the opposite pattern. Main conclusions Our results support the heat balance hypothesis, suggesting that the thermoregulatory abilities of anurans would allow them to reach larger sizes in colder climates by optimizing the trade‐off between heating and cooling rates, whereas a lack of such strategies among urodele faunas would explain why these organisms tend to be smaller in cooler areas. These findings may also have implications for the role of climate warming on the global decline of amphibians.

@article{doi101111j14668238200700309x,
    author = "Olalla‐Tárraga, Miguel Á. and Rodrı́guez, Miguel Á.",
    title = "Energy and interspecific body size patterns of amphibian faunas in Europe and North America: anurans follow Bergmann's rule, urodeles its converse",
    year = "2007",
    journal = "Global Ecology and Biogeography",
    abstract = "ABSTRACT Aim To describe broad‐scale geographical patterns of body size for European and North American amphibian faunas and to explore possible processes underlying these patterns. Specifically, we propose a heat balance hypothesis, as both heat conservation and heat gain determine the heat balance of ectotherms, and test it along with five other hypotheses that have a possible influence on body size gradients: size dependence, migration ability, primary productivity, seasonality and water availability. Location Western Europe and North America north of Mexico. Methods We processed distribution maps for native amphibian species to estimate the mean body size in 110 × 110 km cells and calculated eight environmental predictors to explore the relationship between environmental gradients and the observed patterns. We used least squares regression modelling and model selection approaches based on information theory to evaluate the relative support for each hypothesis. Results We found consistent body size gradients and similar relationships to environmental variables within each amphibian group in Europe and North America. Annual potential evapotranspiration, a measure of environmental energy, was the strongest predictor of mean body size in both regions. However, the contrasting responses to ambient energy in each group resulted in opposite geographical patterns, i.e. anurans increased in size from high‐ to low‐energy areas in both continents and urodeles showed the opposite pattern. Main conclusions Our results support the heat balance hypothesis, suggesting that the thermoregulatory abilities of anurans would allow them to reach larger sizes in colder climates by optimizing the trade‐off between heating and cooling rates, whereas a lack of such strategies among urodele faunas would explain why these organisms tend to be smaller in cooler areas. These findings may also have implications for the role of climate warming on the global decline of amphibians.",
    url = "https://doi.org/10.1111/j.1466-8238.2007.00309.x",
    doi = "10.1111/j.1466-8238.2007.00309.x",
    openalex = "W2171800931",
    references = "doi1023071932171"
}

ABSTRACT Aim Body size is instrumental in influencing animal physiology, morphology, ecology and evolution, as well as extinction risk. I examine several hypotheses regarding the influence of body size on lizard evolution and extinction risk, assessing whether body size influences, or is influenced by, species richness, herbivory, island dwelling and extinction risk. Location World‐wide. Methods I used literature data and measurements of museum and live specimens to estimate lizard body size distributions. Results I obtained body size data for 99% of the world's lizard species. The body size–frequency distribution is highly modal and right skewed and similar distributions characterize most lizard families and lizard assemblages across biogeographical realms. There is a strong negative correlation between mean body size within families and species richness. Herbivorous lizards are larger than omnivorous and carnivorous ones, and aquatic lizards are larger than non‐aquatic species. Diurnal activity is associated with small body size. Insular lizards tend towards both extremes of the size spectrum. Extinction risk increases with body size of species for which risk has been assessed. Main conclusions Small size seems to promote fast diversification of disparate body plans. The absence of mammalian predators allows insular lizards to attain larger body sizes by means of release from predation and allows them to evolve into the top predator niche. Island living also promotes a high frequency of herbivory, which is also associated with large size. Aquatic and nocturnal lizards probably evolve large size because of thermal constraints. The association between large size and high extinction risk, however, probably reflects a bias in the species in which risk has been studied.

@article{doi101111j14668238200800414x,
    author = "Meiri, Shai",
    title = "Evolution and ecology of lizard body sizes",
    year = "2008",
    journal = "Global Ecology and Biogeography",
    abstract = "ABSTRACT Aim Body size is instrumental in influencing animal physiology, morphology, ecology and evolution, as well as extinction risk. I examine several hypotheses regarding the influence of body size on lizard evolution and extinction risk, assessing whether body size influences, or is influenced by, species richness, herbivory, island dwelling and extinction risk. Location World‐wide. Methods I used literature data and measurements of museum and live specimens to estimate lizard body size distributions. Results I obtained body size data for 99\% of the world's lizard species. The body size–frequency distribution is highly modal and right skewed and similar distributions characterize most lizard families and lizard assemblages across biogeographical realms. There is a strong negative correlation between mean body size within families and species richness. Herbivorous lizards are larger than omnivorous and carnivorous ones, and aquatic lizards are larger than non‐aquatic species. Diurnal activity is associated with small body size. Insular lizards tend towards both extremes of the size spectrum. Extinction risk increases with body size of species for which risk has been assessed. Main conclusions Small size seems to promote fast diversification of disparate body plans. The absence of mammalian predators allows insular lizards to attain larger body sizes by means of release from predation and allows them to evolve into the top predator niche. Island living also promotes a high frequency of herbivory, which is also associated with large size. Aquatic and nocturnal lizards probably evolve large size because of thermal constraints. The association between large size and high extinction risk, however, probably reflects a bias in the species in which risk has been studied.",
    url = "https://doi.org/10.1111/j.1466-8238.2008.00414.x",
    doi = "10.1111/j.1466-8238.2008.00414.x",
    openalex = "W2090111574",
    references = "doi10108000222938400770131, openalexw1545181283"
}

@article{doi101016jtree201103005,
    author = "Gardner, Janet L. and Peters, Anne and Kearney, Michael and Joseph, Leo and Heinsohn, Robert",
    title = "Declining body size: a third universal response to warming?",
    year = "2011",
    journal = "Trends in Ecology \& Evolution",
    url = "https://doi.org/10.1016/j.tree.2011.03.005",
    doi = "10.1016/j.tree.2011.03.005",
    openalex = "W1983501589",
    references = "doi101016jygcen200804017, doi101146annurevecolsys110308120159, doi1023071948545"
}

Most ectothermic organisms mature at smaller body sizes when reared in warmer conditions. This phenotypically plastic response, known as the "temperature-size rule" (TSR), is one of the most taxonomically widespread patterns in biology. However, the TSR remains a longstanding life-history puzzle for which no dominant driver has been found. We propose that oxygen supply plays a central role in explaining the magnitude of ectothermic temperature-size responses. Given the much lower oxygen availability and greater effort required to increase uptake in water vs. air, we predict that the TSR in aquatic organisms, especially larger species with lower surface area-body mass ratios, will be stronger than in terrestrial organisms. We performed a meta-analysis of 1,890 body mass responses to temperature in controlled experiments on 169 terrestrial, freshwater, and marine species. This reveals that the strength of the temperature-size response is greater in aquatic than terrestrial species. In animal species of ∼100 mg dry mass, the temperature-size response of aquatic organisms is 10 times greater than in terrestrial organisms (-5.0% °C(-1) vs. -0.5% °C(-1)). Moreover, although the size response of small (<0.1 mg dry mass) aquatic and terrestrial species is similar, increases in species size cause the response to become increasingly negative in aquatic species, as predicted, but on average less negative in terrestrial species. These results support oxygen as a major driver of temperature-size responses in aquatic organisms. Further, the environment-dependent differences parallel latitudinal body size clines, and will influence predicted impacts of climate warming on food production, community structure, and food-web dynamics.

@article{doi101073pnas1210460109,
    author = "Forster, Jack and Hirst, Andrew G. and Atkinson, David",
    title = "Warming-induced reductions in body size are greater in aquatic than terrestrial species",
    year = "2012",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = {Most ectothermic organisms mature at smaller body sizes when reared in warmer conditions. This phenotypically plastic response, known as the "temperature-size rule" (TSR), is one of the most taxonomically widespread patterns in biology. However, the TSR remains a longstanding life-history puzzle for which no dominant driver has been found. We propose that oxygen supply plays a central role in explaining the magnitude of ectothermic temperature-size responses. Given the much lower oxygen availability and greater effort required to increase uptake in water vs. air, we predict that the TSR in aquatic organisms, especially larger species with lower surface area-body mass ratios, will be stronger than in terrestrial organisms. We performed a meta-analysis of 1,890 body mass responses to temperature in controlled experiments on 169 terrestrial, freshwater, and marine species. This reveals that the strength of the temperature-size response is greater in aquatic than terrestrial species. In animal species of ∼100 mg dry mass, the temperature-size response of aquatic organisms is 10 times greater than in terrestrial organisms (-5.0\% °C(-1) vs. -0.5\% °C(-1)). Moreover, although the size response of small (<0.1 mg dry mass) aquatic and terrestrial species is similar, increases in species size cause the response to become increasingly negative in aquatic species, as predicted, but on average less negative in terrestrial species. These results support oxygen as a major driver of temperature-size responses in aquatic organisms. Further, the environment-dependent differences parallel latitudinal body size clines, and will influence predicted impacts of climate warming on food production, community structure, and food-web dynamics.},
    url = "https://doi.org/10.1073/pnas.1210460109",
    doi = "10.1073/pnas.1210460109",
    openalex = "W1970457066",
    references = "doi101016s0169534797010586, doi101038nclimate1259, doi101086284330, doi101111j1469185x200900097x"
}

BACKGROUND: Body size is intimately related to the physiology and ecology of an organism. Therefore, accurate and consistent body mass estimates are essential for inferring numerous aspects of paleobiology in extinct taxa, and investigating large-scale evolutionary and ecological patterns in the history of life. Scaling relationships between skeletal measurements and body mass in birds and mammals are commonly used to predict body mass in extinct members of these crown clades, but the applicability of these models for predicting mass in more distantly related stem taxa, such as non-avian dinosaurs and non-mammalian synapsids, has been criticized on biomechanical grounds. Here we test the major criticisms of scaling methods for estimating body mass using an extensive dataset of mammalian and non-avian reptilian species derived from individual skeletons with live weights. RESULTS: Significant differences in the limb scaling of mammals and reptiles are noted in comparisons of limb proportions and limb length to body mass. Remarkably, however, the relationship between proximal (stylopodial) limb bone circumference and body mass is highly conserved in extant terrestrial mammals and reptiles, in spite of their disparate limb postures, gaits, and phylogenetic histories. As a result, we are able to conclusively reject the main criticisms of scaling methods that question the applicability of a universal scaling equation for estimating body mass in distantly related taxa. CONCLUSIONS: The conserved nature of the relationship between stylopodial circumference and body mass suggests that the minimum diaphyseal circumference of the major weight-bearing bones is only weakly influenced by the varied forces exerted on the limbs (that is, compression or torsion) and most strongly related to the mass of the animal. Our results, therefore, provide a much-needed, robust, phylogenetically corrected framework for accurate and consistent estimation of body mass in extinct terrestrial quadrupeds, which is important for a wide range of paleobiological studies (including growth rates, metabolism, and energetics) and meta-analyses of body size evolution.

@article{doi101186174170071060,
    author = "Campione, Nicolás E. and Evans, David C.",
    title = "A universal scaling relationship between body mass and proximal limb bone dimensions in quadrupedal terrestrial tetrapods",
    year = "2012",
    journal = "BMC Biology",
    abstract = "BACKGROUND: Body size is intimately related to the physiology and ecology of an organism. Therefore, accurate and consistent body mass estimates are essential for inferring numerous aspects of paleobiology in extinct taxa, and investigating large-scale evolutionary and ecological patterns in the history of life. Scaling relationships between skeletal measurements and body mass in birds and mammals are commonly used to predict body mass in extinct members of these crown clades, but the applicability of these models for predicting mass in more distantly related stem taxa, such as non-avian dinosaurs and non-mammalian synapsids, has been criticized on biomechanical grounds. Here we test the major criticisms of scaling methods for estimating body mass using an extensive dataset of mammalian and non-avian reptilian species derived from individual skeletons with live weights. RESULTS: Significant differences in the limb scaling of mammals and reptiles are noted in comparisons of limb proportions and limb length to body mass. Remarkably, however, the relationship between proximal (stylopodial) limb bone circumference and body mass is highly conserved in extant terrestrial mammals and reptiles, in spite of their disparate limb postures, gaits, and phylogenetic histories. As a result, we are able to conclusively reject the main criticisms of scaling methods that question the applicability of a universal scaling equation for estimating body mass in distantly related taxa. CONCLUSIONS: The conserved nature of the relationship between stylopodial circumference and body mass suggests that the minimum diaphyseal circumference of the major weight-bearing bones is only weakly influenced by the varied forces exerted on the limbs (that is, compression or torsion) and most strongly related to the mass of the animal. Our results, therefore, provide a much-needed, robust, phylogenetically corrected framework for accurate and consistent estimation of body mass in extinct terrestrial quadrupeds, which is important for a wide range of paleobiological studies (including growth rates, metabolism, and energetics) and meta-analyses of body size evolution.",
    url = "https://doi.org/10.1186/1741-7007-10-60",
    doi = "10.1186/1741-7007-10-60",
    openalex = "W2053913541",
    references = "christiansen2004mass, doi101016jympev200706018, doi101017cbo9780511608551, doi101017s1464793106007007, doi101086284325, doi101093bioinformaticsbtg412, doi101093sysbio41118, doi101111j146979981985tb04915x, doi101111j251761611995tb02031x, doi101126science1061967, doi101159000452856, doi103998mpub9690664, doi105860choice290302, doi105860choice490282, openalexw1558456135, openalexw2611511275"
}

Viviparity has putatively evolved 115 times in squamates (lizards and snakes), out of only ~ 140 origins in vertebrates, and is apparently related to colder climates and other factors such as body size. Viviparity apparently evolves from oviparity via egg-retention, and such taxa may thus still have the machinery to produce thick-shelled eggs. Parity mode is also associated with variable diversification rates in some groups. We reconstruct ancestral parity modes accounting for state-dependent diversification in a large-scale phylogenetic analysis, and find strong support for an early origin of viviparity at the base of Squamata, and a complex pattern of subsequent transitions. Viviparous lineages have higher rates of speciation and extinction, and greater species turnover through time. Viviparity is associated with lower environmental and body temperatures in lizards and amphisbaenians, but not female mass. These results suggest that parity mode is a labile trait that shifts frequently in response to ecological conditions.

@article{doi101111ele12168,
    author = "Pyron, R. Alexander and Burbrink, Frank T.",
    title = "Early origin of viviparity and multiple reversions to oviparity in squamate reptiles",
    year = "2013",
    journal = "Ecology Letters",
    abstract = "Viviparity has putatively evolved 115 times in squamates (lizards and snakes), out of only \textasciitilde\ 140 origins in vertebrates, and is apparently related to colder climates and other factors such as body size. Viviparity apparently evolves from oviparity via egg-retention, and such taxa may thus still have the machinery to produce thick-shelled eggs. Parity mode is also associated with variable diversification rates in some groups. We reconstruct ancestral parity modes accounting for state-dependent diversification in a large-scale phylogenetic analysis, and find strong support for an early origin of viviparity at the base of Squamata, and a complex pattern of subsequent transitions. Viviparous lineages have higher rates of speciation and extinction, and greater species turnover through time. Viviparity is associated with lower environmental and body temperatures in lizards and amphisbaenians, but not female mass. These results suggest that parity mode is a labile trait that shifts frequently in response to ecological conditions.",
    url = "https://doi.org/10.1111/ele.12168",
    doi = "10.1111/ele.12168",
    openalex = "W2122887852",
    references = "doi101111geb12053, doi101111j15585646201201715x, doi101146annurevecolsys36102003152631"
}

Abstract Aim Temperature influences most components of animal ecology and life history – but what kind of temperature? Physiologists usually examine the influence of body temperatures, while biogeographers and macroecologists tend to focus on environmental temperatures. We aim to examine the relationship between these two measures, to determine the factors that affect lizard body temperatures and to test the effect of both temperature measures on lizard life history. Location World‐wide. Methods We used a large (861 species) global dataset of lizard body temperatures, and the mean annual temperatures across their geographic ranges to examine the relationships between body and mean annual temperatures. We then examined factors influencing body temperatures, and tested for the influence of both on ecological and life‐history traits while accounting for the influence of shared ancestry. Results Body temperatures and mean annual temperatures are uncorrelated. However, accounting for activity time (nocturnal species have low body temperatures), use of space (fossorial and semi‐aquatic species are ‘colder’), insularity (mainland species are ‘hotter’) and phylogeny, the two temperatures are positively correlated. High body temperatures are only associated with larger hatchlings and increased rates of biomass production. Annual temperatures are positively correlated with clutch frequency and annual longevity, and negatively correlated with clutch size, age at first reproduction and longevity. Main conclusions Lizards with low body temperatures do not seem to have ‘slower’ life‐history attributes than species with high body temperatures. The longer seasons prevalent in warm regions, and physiological processes that operate while lizards are inactive (but warm enough), make environmental temperatures better predictors of lizard life‐history variation than body temperatures. This surprisingly greater effect of environmental temperatures on lizard life histories hints that global warming may have a profound influence on lizard ecology and evolution.

@article{doi101111geb12053,
    author = "Meiri, Shai and Bauer, Aaron M. and Chirio, Laurent and Colli, Guarino Rinaldi and Das, Indraneil and Doan, Tiffany M. and Feldman, Anat and Herrera, Fernando‐Castro and Novosolov, Maria and Pafilis, Panayiotis and Pincheira‐Donoso, Daniel and Powney, Gary D. and Torres‐Carvajal, Omar and Uetz, Peter and Damme, Raoul Van",
    title = "Are lizards feeling the heat? A tale of ecology and evolution under two temperatures",
    year = "2013",
    journal = "Global Ecology and Biogeography",
    abstract = "Abstract Aim Temperature influences most components of animal ecology and life history – but what kind of temperature? Physiologists usually examine the influence of body temperatures, while biogeographers and macroecologists tend to focus on environmental temperatures. We aim to examine the relationship between these two measures, to determine the factors that affect lizard body temperatures and to test the effect of both temperature measures on lizard life history. Location World‐wide. Methods We used a large (861 species) global dataset of lizard body temperatures, and the mean annual temperatures across their geographic ranges to examine the relationships between body and mean annual temperatures. We then examined factors influencing body temperatures, and tested for the influence of both on ecological and life‐history traits while accounting for the influence of shared ancestry. Results Body temperatures and mean annual temperatures are uncorrelated. However, accounting for activity time (nocturnal species have low body temperatures), use of space (fossorial and semi‐aquatic species are ‘colder’), insularity (mainland species are ‘hotter’) and phylogeny, the two temperatures are positively correlated. High body temperatures are only associated with larger hatchlings and increased rates of biomass production. Annual temperatures are positively correlated with clutch frequency and annual longevity, and negatively correlated with clutch size, age at first reproduction and longevity. Main conclusions Lizards with low body temperatures do not seem to have ‘slower’ life‐history attributes than species with high body temperatures. The longer seasons prevalent in warm regions, and physiological processes that operate while lizards are inactive (but warm enough), make environmental temperatures better predictors of lizard life‐history variation than body temperatures. This surprisingly greater effect of environmental temperatures on lizard life histories hints that global warming may have a profound influence on lizard ecology and evolution.",
    url = "https://doi.org/10.1111/geb.12053",
    doi = "10.1111/geb.12053",
    openalex = "W2118090567",
    references = "doi101002joc1276, doi101038086277b0, doi10103844766, doi10108000222938400770131, doi101086physzool67130163845, doi101093acprofoso97801985708750011, doi101111j109636421987tb00753x, doi101146annurevecolsys33010802150448, doi1015159781400834112, doi101890038006, doi101890039000, doi1018900621621, doi1020350digitalcsic8682, openalexw1562852527, openalexw2764433274, openalexw393971264, vitt1974body, werner1978observations"
}

Abstract Aim Size is one of the most important and obvious traits of an organism. Both small and large sizes have adaptive advantages and disadvantages. Body size–frequency distributions of most large clades are unimodal and right skewed. Species larger than the mean or range midpoint of body sizes are relatively scarce. Theoretical models suggest evolutionary rates are higher in small organisms with short generation times. Therefore diversification rates are usually thought to be maximal at relatively small body sizes. Empirical studies of the rates of molecular evolution and clade diversification, however, have usually indicated that both are unrelated to body size. Furthermore, it has been claimed that because snakes are longer than lizards, the size–frequency distribution of all squamate species is bimodal overall. We examined the shape of the size–frequency distribution of nearly all Squamata and Rhynchocephalia species, and investigated how size affected diversification rates. Location Global. Methods We collected data on maximum body length for 9805 lepidosaur (squamates and the tuatara) species (99.7% of all species) and converted them to mass using clade‐specific allometric equations. Using methods that test for relationships between continuous traits and speciation and extinction rates on a large, dated phylogeny (4155 species), we investigated the relationship between diversification rates and body size. Results Living squamates span six orders of magnitude in body size, eight when giant extinct snakes and mosasaurs are included. The body size–frequency distributions of snakes and lizards separately, and of all lepidosaur species combined, are unimodal and right skewed. Nonetheless, we find neither linear nor hump‐shaped relationships between size and diversification rates, except in snakes, where speciation and diversification are hump shaped. Main conclusions Despite a clear modality and skew in the body sizes of lepidosaurs, we find little evidence for faster diversification of modal‐sized taxa, perhaps implying that larger‐sized clades are relatively young.

@article{doi101111geb12398,
    author = "Feldman, Anat and Sabath, Niv and Pyron, R. Alexander and Mayrose, Itay and Meiri, Shai",
    title = "Body sizes and diversification rates of lizards, snakes, amphisbaenians and the tuatara",
    year = "2015",
    journal = "Global Ecology and Biogeography",
    abstract = "Abstract Aim Size is one of the most important and obvious traits of an organism. Both small and large sizes have adaptive advantages and disadvantages. Body size–frequency distributions of most large clades are unimodal and right skewed. Species larger than the mean or range midpoint of body sizes are relatively scarce. Theoretical models suggest evolutionary rates are higher in small organisms with short generation times. Therefore diversification rates are usually thought to be maximal at relatively small body sizes. Empirical studies of the rates of molecular evolution and clade diversification, however, have usually indicated that both are unrelated to body size. Furthermore, it has been claimed that because snakes are longer than lizards, the size–frequency distribution of all squamate species is bimodal overall. We examined the shape of the size–frequency distribution of nearly all Squamata and Rhynchocephalia species, and investigated how size affected diversification rates. Location Global. Methods We collected data on maximum body length for 9805 lepidosaur (squamates and the tuatara) species (99.7\% of all species) and converted them to mass using clade‐specific allometric equations. Using methods that test for relationships between continuous traits and speciation and extinction rates on a large, dated phylogeny (4155 species), we investigated the relationship between diversification rates and body size. Results Living squamates span six orders of magnitude in body size, eight when giant extinct snakes and mosasaurs are included. The body size–frequency distributions of snakes and lizards separately, and of all lepidosaur species combined, are unimodal and right skewed. Nonetheless, we find neither linear nor hump‐shaped relationships between size and diversification rates, except in snakes, where speciation and diversification are hump shaped. Main conclusions Despite a clear modality and skew in the body sizes of lepidosaurs, we find little evidence for faster diversification of modal‐sized taxa, perhaps implying that larger‐sized clades are relatively young.",
    url = "https://doi.org/10.1111/geb.12398",
    doi = "10.1111/geb.12398",
    openalex = "W2181803871",
    references = "doi101017cbo9781139167826, doi101038290699a0, doi101086284325, doi101086285558, doi101111geb12053, doi101111j1469185x1966tb01624x, doi101111j2041210x201100169x, doi101111j2041210x201200234x, doi101126science1116030, doi1011861471214811217, doi101371journalpone0051925, doi101890039000, doi1018900814941"
}

@article{doi101016jjtherbio201610004,
    author = "Barroso, Frederico M. and Carretero, Miguel Á. and dos Reis-Silva, Francisco and Sannolo, Marco",
    title = "Assessing the reliability of thermography to infer internal body temperatures of lizards",
    year = "2016",
    journal = "Journal of Thermal Biology",
    url = "https://doi.org/10.1016/j.jtherbio.2016.10.004",
    doi = "10.1016/j.jtherbio.2016.10.004",
    openalex = "W2545859345",
    references = "doi101086physzool37330152398"
}

, to develop a framework within which empiricists can place their work within these limitations, and to facilitate the application of thermal physiology to understanding the biological implications of climate change.

@article{doi101111ele12686,
    author = "Sinclair, Brent J. and Marshall, Katie E. and Sewell, Mary A. and Levesque, Danielle L. and Willett, Christopher S. and Slotsbo, Stine and Dong, Yun‐Wei and Harley, Christopher D. G. and Marshall, David J. and Helmuth, Brian and Huey, Raymond B.",
    title = "Can we predict ectotherm responses to climate change using thermal performance curves and body temperatures?",
    year = "2016",
    journal = "Ecology Letters",
    abstract = ", to develop a framework within which empiricists can place their work within these limitations, and to facilitate the application of thermal physiology to understanding the biological implications of climate change.",
    url = "https://doi.org/10.1111/ele.12686",
    doi = "10.1111/ele.12686",
    openalex = "W2525809904",
    references = "doi101086285141, doi101086409470, doi101086527502, doi101093icb322194"
}

@article{doi101016jneuron201802022,
    author = "Tan, Chan Lek and Knight, Zachary A.",
    title = "Regulation of Body Temperature by the Nervous System",
    year = "2018",
    journal = "Neuron",
    url = "https://doi.org/10.1016/j.neuron.2018.02.022",
    doi = "10.1016/j.neuron.2018.02.022",
    openalex = "W2796279370",
    references = "doi101038272333a0, doi101126science493968"
}

@article{sato2018biologging,
    author = "SATO, Katsufumi and KINOSHITA, Chihiro",
    title = "Biologging Revealed Endothermy of Sea Turtles: Marine Large Reptiles Kept Their Body Temperatures Higher than Ambient Water Temperatures",
    year = "2018",
    journal = "KAGAKU TO SEIBUTSU",
    url = "https://doi.org/10.1271/kagakutoseibutsu.57.29",
    doi = "10.1271/kagakutoseibutsu.57.29",
    number = "1",
    openalex = "W2995455788",
    pages = "29-35",
    volume = "57"
}

@incollection{crossref2024biomathematics,
    title = "Biomathematics",
    year = "2024",
    booktitle = "Dictionary of Toxicology",
    url = "https://doi.org/10.1007/978-981-99-9283-6\_332",
    doi = "10.1007/978-981-99-9283-6\_332",
    pages = "135-136"
}