Life tables

This paper is the first in a series of experimental studies on the factors influencing the duration of life in Drosophila melanogaster. An account of the experimental technique used in these duration of life studies is presented. Four complete life tables for Drosophila are given, and it is shown that this organism follows quantitatively the same general law in respect of the distribution of its mortality as does man. As this work deals only with the duration of imaginal life in Drosophila there is no component in the life tables corresponding to the mortality of infancy and childhood in man. It is shown that there are wide differences in duration of life in different stocks of Drosophila, and that the basis of these differences is hereditary and not environmental. The Drosophila survival line of the life table (lx) runs in general throughout its course between human survival lines of (a) the present time, and (b) about the beginning of the Christian era (Macdonell's data from Roman Africa), the curves being superposed on the basis of the omission of the human mortality of infancy and childhood.

@article{doi101086279836,
    author = "Pearl, Raymond and Parker, Sylvia L.",
    title = "Experimental Studies on the Duration of Life. I. Introductory Discussion of the Duration of Life in Drosophila",
    year = "1921",
    journal = "The American Naturalist",
    abstract = "This paper is the first in a series of experimental studies on the factors influencing the duration of life in Drosophila melanogaster. An account of the experimental technique used in these duration of life studies is presented. Four complete life tables for Drosophila are given, and it is shown that this organism follows quantitatively the same general law in respect of the distribution of its mortality as does man. As this work deals only with the duration of imaginal life in Drosophila there is no component in the life tables corresponding to the mortality of infancy and childhood in man. It is shown that there are wide differences in duration of life in different stocks of Drosophila, and that the basis of these differences is hereditary and not environmental. The Drosophila survival line of the life table (lx) runs in general throughout its course between human survival lines of (a) the present time, and (b) about the beginning of the Christian era (Macdonell's data from Roman Africa), the curves being superposed on the basis of the omission of the human mortality of infancy and childhood.",
    url = "https://doi.org/10.1086/279836",
    doi = "10.1086/279836",
    openalex = "W2066782185"
}

P. H. Leslie, R. M. Ranson, The Mortality, Fertility and Rate of Natural Increase of the Vole (Microtus agrestis) as Observed in the Laboratory, Journal of Animal Ecology, Vol. 9, No. 1 (May, 1940), pp. 27-52

@article{doi1023071425,
    author = "Leslie, Paula and Ranson, R. M.",
    title = "The Mortality, Fertility and Rate of Natural Increase of the Vole (Microtus agrestis) as Observed in the Laboratory",
    year = "1940",
    journal = "Journal of Animal Ecology",
    abstract = "P. H. Leslie, R. M. Ranson, The Mortality, Fertility and Rate of Natural Increase of the Vole (Microtus agrestis) as Observed in the Laboratory, Journal of Animal Ecology, Vol. 9, No. 1 (May, 1940), pp. 27-52",
    url = "https://doi.org/10.2307/1425",
    doi = "10.2307/1425",
    openalex = "W2319946021",
    references = "doi101017s002217240000961x, doi10108001621459192510503498, doi101093ajcp1511552b, doi101098rspb19330061, doi1023071282, doi1023072276750, doi1023072277387, doi1023072298330, doi1023072965538, doi105962bhltitle27468"
}

@article{deevey1947life,
    author = "Deevey, Edward S.",
    title = "Life Tables for Natural Populations of Animals",
    year = "1947",
    journal = "The Quarterly Review of Biology",
    url = "https://doi.org/10.1086/395888",
    doi = "10.1086/395888",
    number = "4",
    pages = "283-314",
    volume = "22"
}

@article{deevey1947life1,
    author = "Deevey, E. S. and Jr",
    title = "Life tables for natural populations of animals",
    year = "1947",
    journal = "Quarterly Review of Biology, v. 22, p. 283-314",
    note = "talkorigins\_source = {true}; raw\_reference = {Deevey, E. S., Jr., 1947, Life tables for natural populations of animals: Quarterly Review of Biology, v. 22, p. 283-314.}"
}

@article{doi101086395888,
    author = "Deevey, Edward S.",
    title = "Life Tables for Natural Populations of Animals",
    year = "1947",
    journal = "The Quarterly Review of Biology",
    url = "https://doi.org/10.1086/395888",
    doi = "10.1086/395888",
    openalex = "W1571519736",
    references = "doi101017s0025315400010109, doi101086394476, doi101139f40008, doi1023071232, doi1023071375039, doi1023071437796, doi1023071438245, doi1023071943293, doi1023071948601, openalexw622324087"
}

@article{doi1023071578,
    author = "Solomon, M. E.",
    title = "The Natural Control of Animal Populations",
    year = "1949",
    journal = "Journal of Animal Ecology",
    url = "https://doi.org/10.2307/1578",
    doi = "10.2307/1578",
    openalex = "W2324851947",
    references = "beauchamp1932competitive, doi101002jez1400650103, doi101007bf01847581, doi101017s0007485300026274, doi101086394454, doi101093icesjms313, doi1023071611, doi1023071930461a, doi1023071943293, doi1023071948641, doi1025919dbrbzx18"
}

@article{connell1961effects,
    author = "Connell, Joseph H.",
    title = "Effects of Competition, Predation by Thais lapillus, and Other Factors on Natural Populations of the Barnacle Balanus balanoides",
    year = "1961",
    journal = "Ecological Monographs",
    url = "https://doi.org/10.2307/1950746",
    doi = "10.2307/1950746",
    number = "1",
    pages = "61-104",
    volume = "31"
}

@article{doi1023073798722,
    author = "Davis, David E. and Slobodkin, Lawrence B.",
    title = "Growth and Regulation of Animal Populations",
    year = "1962",
    journal = "Journal of Wildlife Management",
    url = "https://doi.org/10.2307/3798722",
    doi = "10.2307/3798722",
    openalex = "W2378517356"
}

Abstract This paper illustrates the application of life table techniques to data on school enrollments as a means of estimating school life expectancy. The school life tables which are derived are double decrement tables which show the joint effects of death and school dropouts on school attendance patterns. Such tables drawn up for 1950–52 and 1957–59 show the improvements in school retention by age during the last decade. Modifications of this type of analysis which would incorporate the probability of other phenomena occurring and extend the applications to other population groups are suggested.

@article{doi10108001621459196310480692,
    author = "Stockwell, Edward G. and Nam, Charles B.",
    title = "Illustrative Tables of School Life",
    year = "1963",
    journal = "Journal of the American Statistical Association",
    abstract = "Abstract This paper illustrates the application of life table techniques to data on school enrollments as a means of estimating school life expectancy. The school life tables which are derived are double decrement tables which show the joint effects of death and school dropouts on school attendance patterns. Such tables drawn up for 1950–52 and 1957–59 show the improvements in school retention by age during the last decade. Modifications of this type of analysis which would incorporate the probability of other phenomena occurring and extend the applications to other population groups are suggested.",
    url = "https://doi.org/10.1080/01621459.1963.10480692",
    doi = "10.1080/01621459.1963.10480692",
    openalex = "W2092147590"
}

@article{doi1023074510986,
    author = "McCamey, Franklin and Slobodkin, Lawrence B.",
    title = "Growth and Regulation of Animal Populations",
    year = "1963",
    journal = "Bird-Banding",
    url = "https://doi.org/10.2307/4510986",
    doi = "10.2307/4510986",
    openalex = "W2017549609"
}

@article{doi101007bf02514729,
    author = "Iwao, Syun'iti",
    title = "A new regression method for analyzing the aggregation pattern of animal populations",
    year = "1968",
    journal = "Population Ecology",
    url = "https://doi.org/10.1007/bf02514729",
    doi = "10.1007/bf02514729",
    openalex = "W2090769784",
    references = "doi101038189732a0"
}

With a growing world population and increasingly demanding consumers, the production of sufficient protein from livestock, poultry, and fish represents a serious challenge for the future. Approximately 1,900 insect species are eaten worldwide, mainly in...Read More

@article{doi101146annureven14010169001135,
    author = "Harcourt, D. G.",
    title = "The Development and Use of Life Tables in the Study of Natural Insect Populations",
    year = "1969",
    journal = "Annual Review of Entomology",
    abstract = "With a growing world population and increasingly demanding consumers, the production of sufficient protein from livestock, poultry, and fish represents a serious challenge for the future. Approximately 1,900 insect species are eaten worldwide, mainly in...Read More",
    url = "https://doi.org/10.1146/annurev.en.14.010169.001135",
    doi = "10.1146/annurev.en.14.010169.001135",
    openalex = "W1984739220"
}

"Switching" in predators which attack several prey species potentially can stabilize the numbers in prey populations. In switching, the number of attacks upon a species is disproportionately large when the species is abundant relative to other prey, and disproportionately small when the species is relatively rare. The null case for two prey species can be written: P 1 /P 2 = cN 1 /N 2, where P 1 /P 2 is the ratio of the two prey expected in the diet, N 1 /N 2 is the ratio given and c is a proportionality constant. Predators were sea—shore snails and prey were mussels and barnacles. Experiments in the laboratory modelled aspects of various natural situations. When the predator had a strong preference (c) between prey the data and the "null case" model were in good agreement. Preference could not altered by subjecting predators to training regimens. When preference was weak the data did not fit the model replicates were variable. Predators could be trained easily to one or other prey species. From a number of experiments it was concluded that in the weak—preference case no switch would occur in nature except where there is an opportunity for predators to become trained to the abundant species. A patchy distribution of the abundant prey could provide this opportunity. Given one prey species, snails caused a decreasing percentage mortality as prey numbers increased. This occurred also with 2 prey species present when preference was strong. When preference was weak the form of the response was unclear. When switching occurred the percentage prey mortality increased with prey density, giving potentially stabilizing mortality. The consequences of these conclusions for prey population regulation and for diversity are discussed.

@article{doi1023071942352,
    author = "Murdoch, William W.",
    title = "Switching in General Predators: Experiments on Predator Specificity and Stability of Prey Populations",
    year = "1969",
    journal = "Ecological Monographs",
    abstract = {"Switching" in predators which attack several prey species potentially can stabilize the numbers in prey populations. In switching, the number of attacks upon a species is disproportionately large when the species is abundant relative to other prey, and disproportionately small when the species is relatively rare. The null case for two prey species can be written: P 1 /P 2 = cN 1 /N 2, where P 1 /P 2 is the ratio of the two prey expected in the diet, N 1 /N 2 is the ratio given and c is a proportionality constant. Predators were sea—shore snails and prey were mussels and barnacles. Experiments in the laboratory modelled aspects of various natural situations. When the predator had a strong preference (c) between prey the data and the "null case" model were in good agreement. Preference could not altered by subjecting predators to training regimens. When preference was weak the data did not fit the model replicates were variable. Predators could be trained easily to one or other prey species. From a number of experiments it was concluded that in the weak—preference case no switch would occur in nature except where there is an opportunity for predators to become trained to the abundant species. A patchy distribution of the abundant prey could provide this opportunity. Given one prey species, snails caused a decreasing percentage mortality as prey numbers increased. This occurred also with 2 prey species present when preference was strong. When preference was weak the form of the response was unclear. When switching occurred the percentage prey mortality increased with prey density, giving potentially stabilizing mortality. The consequences of these conclusions for prey population regulation and for diversity are discussed.},
    url = "https://doi.org/10.2307/1942352",
    doi = "10.2307/1942352",
    openalex = "W2032839068",
    references = "connell1961effects, doi1023071578, doi1023071950746, doi104039entm9745fv"
}

The tremendous variation in the life-history patterns of organisms is best explained as adaptive.any organism has a limited amount of resources at its disposal, and these have to be partitioned between reproductive and nonreproductive activities. A larger share of resources to reproductive activities, that is, a higher reproductive effort at any age, leads to a better reproductive performance at that age; this may be considered a as profit function. This reproductive effort also leads to a reduction in survival and growth and consequent diminution of the reproductive contribution of the succeeding stages in the life history; this may be considered as a cost function. Natural selection would tend to an adjustment of the reproductive effort at every age such that the overall fitness of the life history would be maximized. A model of life history processes has been developed on the basis of these considerations. It leads to the following predictions: 1. If the form of the profit function is convex, or that of the cost function concave, the optimal strategy may be to breed repeatedly. Otherwise, the optimal strategy is to breed only once in a suicidal effort like a salmon (big-bang reproduction). 2. The value of reproductive effort continuously increases with age in the case of repeated reproducers. 3. If all the stages in the life history following a certain age are adversely affected, the age of reproduction will tend to be lowered in the case of big-bang reproducers, and the reproductive effort at all ages preceding that stage will tend to increase in the case of repeated reproducers. 4. As the reproductive potential increases with size at a slower rate, reproductive effort will be lower at maturity, reproductive effort will increase at a higher rate with age, and growth will continue beyond maturity. 5. A uniform change in the probability of survival from one age to the next at all ages would have no effect by itself, on the age of reproduction in big-bang breeders or on the distribution of reproductive effort with age in the repeated reproducers. 6. Such a change in survivorship would lead to a change in the equilibrium density of a population. If the population is resource limited, this would affect the availability of resources to the members, of the population in such a way that an increase in mortality would increase the availability of the resources. 7. For a resource-limited organism a greater availability of resources would lead to a lowering of the age of reproduction in the case of the big-bang breeders, and to a greater reproductive effort at ail ages for the repeated breeders.

@article{doi101086282637,
    author = "Gadgil, Madhav and Bossert, William H.",
    title = "Life Historical Consequences of Natural Selection",
    year = "1970",
    journal = "The American Naturalist",
    abstract = "The tremendous variation in the life-history patterns of organisms is best explained as adaptive.any organism has a limited amount of resources at its disposal, and these have to be partitioned between reproductive and nonreproductive activities. A larger share of resources to reproductive activities, that is, a higher reproductive effort at any age, leads to a better reproductive performance at that age; this may be considered a as profit function. This reproductive effort also leads to a reduction in survival and growth and consequent diminution of the reproductive contribution of the succeeding stages in the life history; this may be considered as a cost function. Natural selection would tend to an adjustment of the reproductive effort at every age such that the overall fitness of the life history would be maximized. A model of life history processes has been developed on the basis of these considerations. It leads to the following predictions: 1. If the form of the profit function is convex, or that of the cost function concave, the optimal strategy may be to breed repeatedly. Otherwise, the optimal strategy is to breed only once in a suicidal effort like a salmon (big-bang reproduction). 2. The value of reproductive effort continuously increases with age in the case of repeated reproducers. 3. If all the stages in the life history following a certain age are adversely affected, the age of reproduction will tend to be lowered in the case of big-bang reproducers, and the reproductive effort at all ages preceding that stage will tend to increase in the case of repeated reproducers. 4. As the reproductive potential increases with size at a slower rate, reproductive effort will be lower at maturity, reproductive effort will increase at a higher rate with age, and growth will continue beyond maturity. 5. A uniform change in the probability of survival from one age to the next at all ages would have no effect by itself, on the age of reproduction in big-bang breeders or on the distribution of reproductive effort with age in the repeated reproducers. 6. Such a change in survivorship would lead to a change in the equilibrium density of a population. If the population is resource limited, this would affect the availability of resources to the members, of the population in such a way that an increase in mortality would increase the availability of the resources. 7. For a resource-limited organism a greater availability of resources would lead to a lowering of the age of reproduction in the case of the big-bang breeders, and to a greater reproductive effort at ail ages for the repeated breeders.",
    url = "https://doi.org/10.1086/282637",
    doi = "10.1086/282637",
    openalex = "W2047752581",
    references = "doi101086282286, doi101086400074"
}

Summary The analysis of censored failure times is considered. It is assumed that on each individual are available values of one or more explanatory variables. The hazard function (age-specific failure rate) is taken to be a function of the explanatory variables and unknown regression coefficients multiplied by an arbitrary and unknown function of time. A conditional likelihood is obtained, leading to inferences about the unknown regression coefficients. Some generalizations are outlined.

@article{doi101111j251761611972tb00899x,
    author = "Cox, D. R.",
    title = "Regression Models and Life-Tables",
    year = "1972",
    journal = "Journal of the Royal Statistical Society Series B (Statistical Methodology)",
    abstract = "Summary The analysis of censored failure times is considered. It is assumed that on each individual are available values of one or more explanatory variables. The hazard function (age-specific failure rate) is taken to be a function of the explanatory variables and unknown regression coefficients multiplied by an arbitrary and unknown function of time. A conditional likelihood is obtained, leading to inferences about the unknown regression coefficients. Some generalizations are outlined.",
    url = "https://doi.org/10.1111/j.2517-6161.1972.tb00899.x",
    doi = "10.1111/j.2517-6161.1972.tb00899.x",
    openalex = "W3147894994",
    references = "doi10108001621459195810501452"
}

A life table model which can recognize increments (or entrants) as well as decrements has proven to be of considerable value in the analysis of marital status patterns, labor force participation patterns, and other areas of substantive interest. Nonetheless, relatively little work has been done on the methodology of increment-decrement (or combined) life tables. The present paper reviews the general, recursive solution of Schoen and Nelson (1974), develops explicit solutions for three cases of particular interest, and compares alternative approaches to the construction of increment-decrement tables.

@article{doi1023072060768,
    author = "Schoen, Robert",
    title = "Constructing increment-decrement life tables",
    year = "1975",
    journal = "Demography",
    abstract = "A life table model which can recognize increments (or entrants) as well as decrements has proven to be of considerable value in the analysis of marital status patterns, labor force participation patterns, and other areas of substantive interest. Nonetheless, relatively little work has been done on the methodology of increment-decrement (or combined) life tables. The present paper reviews the general, recursive solution of Schoen and Nelson (1974), develops explicit solutions for three cases of particular interest, and compares alternative approaches to the construction of increment-decrement tables.",
    url = "https://doi.org/10.2307/2060768",
    doi = "10.2307/2060768",
    openalex = "W2072817373"
}

This review organizes ideas on the evolution of life histories. The key life-history traits are brood size, size of young, the age distribution of reproductive effort, the interaction of reproductive effort with adult mortality, and the variation in these traits among an individual's progeny. The general theoretical problem is to predict which combinations of traits will evolve in organisms living in specified circumstances. First consider single traits. Theorists have made the following predictions: (1) Where adult exceeds juvenile mortality, the organism should reproduce only once in its lifetime. Where juvenile exceeds adult mortality, the organism should reproduce several times. (2) Brood size should macimize the number of young surviving to maturity, summed over the lifetime of the parent. But when optimum brood-size unpredictably in time, smaller broods should be favored because they decrease the chances of total failure on a given attempt. (3) In expanding populations, selection should minimize age at maturity. In stable populations, when reproductive success depends on size, age, or social status, or when adult exceeds juvenile mortality, then maturation should be delayed, as it should be in declining populations. (4) Young should increase in size at birth with increased predation risk, and decrease in size with increased resource availability. Theorists have also predicted that only particular combinations of traits should occur in specified circumstances. (5) In growing populations, age at maturity should be minimized, reproductive effort concentrated early in life, and brood size increased. (6) One view holds that in stable environments, late maturity, broods, a few, large young, parental care, and small reproductive efforts should be favored (K-selection). In fluctuating environments, early maturity, many small young, reduced parental care, and large reproductive efforts should be favored (r-selection). (7) But another view holds that when juvenile mortality fluctuates more than adult mortality, the traits associated with stable and fluctuating environments should be reversed. We need experiments that test the assumptions and predictions reviewed here, more comprehensive theory that makes more readily falsifiable predictions, and examination of different definitions of fitness.

@article{doi101086409052,
    author = "Stearns, Stephen C.",
    title = "Life-History Tactics: A Review of the Ideas",
    year = "1976",
    journal = "The Quarterly Review of Biology",
    abstract = "This review organizes ideas on the evolution of life histories. The key life-history traits are brood size, size of young, the age distribution of reproductive effort, the interaction of reproductive effort with adult mortality, and the variation in these traits among an individual's progeny. The general theoretical problem is to predict which combinations of traits will evolve in organisms living in specified circumstances. First consider single traits. Theorists have made the following predictions: (1) Where adult exceeds juvenile mortality, the organism should reproduce only once in its lifetime. Where juvenile exceeds adult mortality, the organism should reproduce several times. (2) Brood size should macimize the number of young surviving to maturity, summed over the lifetime of the parent. But when optimum brood-size unpredictably in time, smaller broods should be favored because they decrease the chances of total failure on a given attempt. (3) In expanding populations, selection should minimize age at maturity. In stable populations, when reproductive success depends on size, age, or social status, or when adult exceeds juvenile mortality, then maturation should be delayed, as it should be in declining populations. (4) Young should increase in size at birth with increased predation risk, and decrease in size with increased resource availability. Theorists have also predicted that only particular combinations of traits should occur in specified circumstances. (5) In growing populations, age at maturity should be minimized, reproductive effort concentrated early in life, and brood size increased. (6) One view holds that in stable environments, late maturity, broods, a few, large young, parental care, and small reproductive efforts should be favored (K-selection). In fluctuating environments, early maturity, many small young, reduced parental care, and large reproductive efforts should be favored (r-selection). (7) But another view holds that when juvenile mortality fluctuates more than adult mortality, the traits associated with stable and fluctuating environments should be reversed. We need experiments that test the assumptions and predictions reviewed here, more comprehensive theory that makes more readily falsifiable predictions, and examination of different definitions of fitness.",
    url = "https://doi.org/10.1086/409052",
    doi = "10.1086/409052",
    openalex = "W1994811904",
    references = "deevey1947life, doi101001jama195002910300087029, doi1010160022519366901846, doi1010160040580974900537, doi101086282461, doi101086282697, doi101086394476, doi101086395888, doi101086400074, doi101093biomet333183, doi101093icb141249, doi101111j1474919x1947tb04155x, doi101111j155856461969tb03489x, doi101139f54039, doi1015159781400820108, doi1015159781400881376, doi1023071935217, doi1023071935638, doi1023072965538, doi102307jctvx5wbbh, doi10432497813151292667, doi105962bhltitle27468, openalexw1532540194, openalexw2000871817"
}

@incollection{deevey1977life,
    author = "Deevey, Edward S.",
    title = "Life Tables for Natural Populations of Animals",
    year = "1977",
    booktitle = "Biomathematics",
    url = "https://doi.org/10.1007/978-3-642-81046-6\_9",
    doi = "10.1007/978-3-642-81046-6\_9",
    pages = "61-74"
}

@incollection{doi10100797836428104669,
    author = "Deevey, Edward S.",
    title = "Life Tables for Natural Populations of Animals",
    year = "1977",
    booktitle = "Biomathematics",
    url = "https://doi.org/10.1007/978-3-642-81046-6\_9",
    doi = "10.1007/978-3-642-81046-6\_9",
    openalex = "W3022991479",
    references = "doi101017s0025315400010109, doi101086394476, doi101139f40008, doi1023071232, doi1023071438245, doi1023071943293, doi1023071948601, doi1023073795657, doi1023073796179, openalexw622324087"
}

SUMMARY The paper examines the factors which generate various patterns of dispersion in the distribution of parasites within their host populations. Particular emphasis is placed on the role played by chance elements in the growth and decay of parasite populations and on the influence of different types of demographic processes. It is argued that observed distributions are dynamic, rather than static, entities generated by opposing forces, some acting to create over-dispersion and others acting to generate under-dispersion. Monte Carlo simulation experiments, based on probability models of the growth and decay of host and parasite populations, are used to study the dynamics of parasite dispersion. Attention is specifically focused on the role played by parasite-induced host mortality. It is shown that, for certain types of host–parasite associations, convex curves of mean parasite abundance in relation to age (age-intensity curves), concomitant with a decline in the degree of dispersion in the older age classes of hosts, may be evidence of the induction of host mortality by parasite infection. Empirical evidence is examined in light of this prediction. In general, however, simulation studies highlight the technical difficulties inherent in establishing clear evidence of parasite-induced host mortality from ecological studies of hosts and parasites in their natural habitats.

@article{doi101017s0031182000055347,
    author = "Anderson, Roy M. and Gordon, David M.",
    title = "Processes influencing the distribution of parasite numbers within host populations with special emphasis on parasite-induced host mortalities",
    year = "1982",
    journal = "Parasitology",
    abstract = "SUMMARY The paper examines the factors which generate various patterns of dispersion in the distribution of parasites within their host populations. Particular emphasis is placed on the role played by chance elements in the growth and decay of parasite populations and on the influence of different types of demographic processes. It is argued that observed distributions are dynamic, rather than static, entities generated by opposing forces, some acting to create over-dispersion and others acting to generate under-dispersion. Monte Carlo simulation experiments, based on probability models of the growth and decay of host and parasite populations, are used to study the dynamics of parasite dispersion. Attention is specifically focused on the role played by parasite-induced host mortality. It is shown that, for certain types of host–parasite associations, convex curves of mean parasite abundance in relation to age (age-intensity curves), concomitant with a decline in the degree of dispersion in the older age classes of hosts, may be evidence of the induction of host mortality by parasite infection. Empirical evidence is examined in light of this prediction. In general, however, simulation studies highlight the technical difficulties inherent in establishing clear evidence of parasite-induced host mortality from ecological studies of hosts and parasites in their natural habitats.",
    url = "https://doi.org/10.1017/s0031182000055347",
    doi = "10.1017/s0031182000055347",
    openalex = "W2080898826",
    references = "bailey1961stochastic, doi101038189732a0, doi101038280455a0, doi1023072282020, doi1023072312029"
}

This study was designed to demonstrate the feasibility of forecasting functional health for the elderly. Using life-table techniques, we analyzed the expected remaining years of functional well-being, in terms of the activities of daily living, for noninstitutionalized elderly people living in Massachusetts in 1974. The expected years, or active life expectancy, showed a decrease, from 10 years for those aged 65 to 70 years to 2.9 for those 85 or older. Active life expectancy was shorter for the poor than for others, and women had a longer average duration of expected dependence than men. The measure of active life expectancy provides important information about health at a given population level, in terms other than death. This information can be used for actuarial purposes in planning and policy making. It is also useful in identifying high-risk populations for which preventive health care and medical care can compress morbidity during the last years of life.

@article{doi101056nejm198311173092005,
    author = "Katz, Sidney and Branch, Laurence G. and Branson, Michael and Papsidero, Joseph A. and Beck, John C. and Greer, David S.",
    title = "Active Life Expectancy",
    year = "1983",
    journal = "New England Journal of Medicine",
    abstract = "This study was designed to demonstrate the feasibility of forecasting functional health for the elderly. Using life-table techniques, we analyzed the expected remaining years of functional well-being, in terms of the activities of daily living, for noninstitutionalized elderly people living in Massachusetts in 1974. The expected years, or active life expectancy, showed a decrease, from 10 years for those aged 65 to 70 years to 2.9 for those 85 or older. Active life expectancy was shorter for the poor than for others, and women had a longer average duration of expected dependence than men. The measure of active life expectancy provides important information about health at a given population level, in terms other than death. This information can be used for actuarial purposes in planning and policy making. It is also useful in identifying high-risk populations for which preventive health care and medical care can compress morbidity during the last years of life.",
    url = "https://doi.org/10.1056/nejm198311173092005",
    doi = "10.1056/nejm198311173092005",
    openalex = "W2021480659",
    references = "deevey1947life, doi1010160021968181900679, doi101056nejm198007173030304, doi10108001621459196310480692, doi101086395888, doi1010970000565019800600000001, doi1010970000565019821100000012, doi102190uurl2ryuwrydey3k, doi1023072060768, doi1023072068501, doi104159harvard9780674497474"
}

We used life-history theory to predict reaction norms for age and size at maturation. We assumed that fecundity increases with size and that juvenile mortality rates of offspring decrease as ages-at-maturity of parents increase, then calculated the reaction norm by varying growth rate and calculating an optimal age at maturity for each growth rate. The reaction norm for maturation should take one of at least four shapes that depend on specific relations between changes in growth rates and changes in adult mortality rates, juvenile mortality rates, or both. Most organisms should mature neither at a fixed size nor at a fixed age, but along an age-size trajectory. The model makes possible a clear distinction between the genetic and phenotypic components of variation. The evolved response to selection is reflected in the shape and position of the reaction norm. The phenotypic response of a single organism to rapid or slow growth is defined by the location of its maturation event as a point on the reaction norm. A quantitative test with data from 19 populations and species of fish showed that predictions were in good agreement with observations (r = 0.93, P < 0.0001). The predictions of the model also agreed qualitatively with observed phenotypic variation in age and size at maturity in humans, platyfish, fruit flies, and red deer. This preliminary success suggests that experiments designed to test the predictions directly will be worthwhile.

@article{doi101111j155856461986tb00560x,
    author = "Stearns, Stephen C. and Koella, Jacob C.",
    title = "THE EVOLUTION OF PHENOTYPIC PLASTICITY IN LIFE‐HISTORY TRAITS: PREDICTIONS OF REACTION NORMS FOR AGE AND SIZE AT MATURITY",
    year = "1986",
    journal = "Evolution",
    abstract = "We used life-history theory to predict reaction norms for age and size at maturation. We assumed that fecundity increases with size and that juvenile mortality rates of offspring decrease as ages-at-maturity of parents increase, then calculated the reaction norm by varying growth rate and calculating an optimal age at maturity for each growth rate. The reaction norm for maturation should take one of at least four shapes that depend on specific relations between changes in growth rates and changes in adult mortality rates, juvenile mortality rates, or both. Most organisms should mature neither at a fixed size nor at a fixed age, but along an age-size trajectory. The model makes possible a clear distinction between the genetic and phenotypic components of variation. The evolved response to selection is reflected in the shape and position of the reaction norm. The phenotypic response of a single organism to rapid or slow growth is defined by the location of its maturation event as a point on the reaction norm. A quantitative test with data from 19 populations and species of fish showed that predictions were in good agreement with observations (r = 0.93, P < 0.0001). The predictions of the model also agreed qualitatively with observed phenotypic variation in age and size at maturity in humans, platyfish, fruit flies, and red deer. This preliminary success suggests that experiments designed to test the predictions directly will be worthwhile.",
    url = "https://doi.org/10.1111/j.1558-5646.1986.tb00560.x",
    doi = "10.1111/j.1558-5646.1986.tb00560.x",
    openalex = "W2329565638",
    references = "doi101086400074, doi101126science18241191305, doi1023071935217"
}

Abstract This paper reviews a series of approaches to the study of density dependence, regulation and variability in terrestrial animals, by using single-species, multispecies and life table time series data. Special emphasis is given to the degree of density dependence in the level of variability, which is seldom discussed in this context, but which is conceptually related to population regulation. Broad patterns in density dependence, regulation and variability in vertebrates and arthropods are described, with some more specific results for moths and aphids. Vertebrates have generally less variable populations than arthropods, which is the only well documented, consistent pattern in population variability. The degree of density dependence of variability is negatively correlated with the average level of variability, suggesting that generally the more regulated populations are less variable. Most population studies, especially on insects, have involved outbreak species with complex dynamics, which may explain the common failures to detect density dependence in natural populations. In British moths, density dependence is less obvious in the more abundant species. The study of uncommon and rare species remains a major challenge for population ecology.

@article{doi101098rstb19900188,
    author = "Hanski, Ilkka",
    title = "Density dependence, regulation and variability in animal populations",
    year = "1990",
    journal = "Philosophical Transactions of the Royal Society B Biological Sciences",
    abstract = "Abstract This paper reviews a series of approaches to the study of density dependence, regulation and variability in terrestrial animals, by using single-species, multispecies and life table time series data. Special emphasis is given to the degree of density dependence in the level of variability, which is seldom discussed in this context, but which is conceptually related to population regulation. Broad patterns in density dependence, regulation and variability in vertebrates and arthropods are described, with some more specific results for moths and aphids. Vertebrates have generally less variable populations than arthropods, which is the only well documented, consistent pattern in population variability. The degree of density dependence of variability is negatively correlated with the average level of variability, suggesting that generally the more regulated populations are less variable. Most population studies, especially on insects, have involved outbreak species with complex dynamics, which may explain the common failures to detect density dependence in natural populations. In British moths, density dependence is less obvious in the more abundant species. The study of uncommon and rare species remains a major challenge for population ecology.",
    url = "https://doi.org/10.1098/rstb.1990.0188",
    doi = "10.1098/rstb.1990.0188",
    openalex = "W2119224789",
    references = "doi101007bf00384946, doi101007bf01556726, doi101038189732a0, doi101086284105, doi101093besa153237, doi101111j109583121991tb00552x, doi101126science24148721441, doi1023075465, openalexw1500291103, openalexw2038423019"
}

Interspecific patterns of fish life histories were evaluated in relation to several theoretical models of life-history evolution. Data were gathered for 216 North American fish species (57 families) to explore relationships among variables and to ordinate species. Multivariate tests, performed on freshwater, marine, and combined data matrices, repeatedly identified a gradient associating later-maturing fishes with higher fecundity, small eggs, and few bouts of reproduction during a short spawning season and the opposite suite of traits with small fishes. A second strong gradient indicated positive associations between parental care, egg size, and extended breeding seasons. Phylogeny affected each variable, and some higher taxonomic groupings were associated with particular life-history strategies. High-fecundity characteristics tended to be associated with large species ranges in the marine environment. Age at maturation, adult growth rate, life span, and egg size positively correlated with anadromy. Parental care was inversely correlated with median latitude. A trilateral continuum based on essential trade-offs among three demographic variables predicts many of the correlations among life-history traits. This framework has implications for predicting population responses to diverse natural and anthropogenic disturbances and provides a basis for comparing responses of different species to the same disturbance.

@article{doi101139f92242,
    author = "Winemiller, Kirk O. and Rose, Kenneth A.",
    title = "Patterns of Life-History Diversification in North American Fishes: implications for Population Regulation",
    year = "1992",
    journal = "Canadian Journal of Fisheries and Aquatic Sciences",
    abstract = "Interspecific patterns of fish life histories were evaluated in relation to several theoretical models of life-history evolution. Data were gathered for 216 North American fish species (57 families) to explore relationships among variables and to ordinate species. Multivariate tests, performed on freshwater, marine, and combined data matrices, repeatedly identified a gradient associating later-maturing fishes with higher fecundity, small eggs, and few bouts of reproduction during a short spawning season and the opposite suite of traits with small fishes. A second strong gradient indicated positive associations between parental care, egg size, and extended breeding seasons. Phylogeny affected each variable, and some higher taxonomic groupings were associated with particular life-history strategies. High-fecundity characteristics tended to be associated with large species ranges in the marine environment. Age at maturation, adult growth rate, life span, and egg size positively correlated with anadromy. Parental care was inversely correlated with median latitude. A trilateral continuum based on essential trade-offs among three demographic variables predicts many of the correlations among life-history traits. This framework has implications for predicting population responses to diverse natural and anthropogenic disturbances and provides a basis for comparing responses of different species to the same disturbance.",
    url = "https://doi.org/10.1139/f92-242",
    doi = "10.1139/f92-242",
    openalex = "W1972344148",
    references = "doi101086282697, doi101086409052"
}

The understanding of the dynamics of animal populations and of related ecological and evolutionary issues frequently depends on a direct analysis of life history parameters. For instance, examination of trade—offs between reproduction and survival usually rely on individually marked animals, for which the exact time of death is most often unknown, because marked individuals cannot be followed closely through time. Thus, the quantitative analysis of survival studies and experiments must be based on capture—recapture (or resighting) models which consider, besides the parameters of primary interest, recapture or resighting rates that are nuisance parameters. Capture—recapture models oriented to estimation of survival rates are the result of a recent change in emphasis from earlier approaches in which population size was the most important parameter, survival rates having been first introduced as nuisance parameters. This emphasis on survival rates in capture—recapture models developed rapidly in the 1980s and used as a basic structure the Cormack—Jolly—Seber survival model applied to an homogeneous group of animals, with various kinds of constraints on the model parameters. These approaches are conditional on first captures; hence they do not attempt to model the initial capture of unmarked animals as functions of population abundance in addition to survival and capture probabilities. This paper synthesizes, using a common framework, these recent developments together with new ones, with an emphasis on flexibility in modeling, model selection, and the analysis of multiple data sets. The effects on survival and capture rates of time, age, and categorical variables characterizing the individuals (e.g., sex) can be considered, as well as interactions between such effects. This "analysis of variance" philosophy emphasizes the structure of the survival and capture process rather than the technical characteristics of any particular model. The flexible array of models encompassed in this synthesis uses a common notation. As a result of the great level of flexibility and relevance achieved, the focus is changed from fitting a particular model to model building and model selection. The following procedure is recommended: (1) start from a global model compatible with the biology of the species studied and with the design of the study, and assess its fit; (2) select a more parsimonious model using Akaike's Information Criterion to limit the number of formal tests; (3) test for the most important biological questions by comparing this model with neighboring ones using likelihood ratio tests; and (4) obtain maximum likelihood estimates of model parameters with estimates of precision. Computer software is critical, as few of the models now available have parameter estimators that are in closed form. A comprehensive table of existing computer software is provided. We used RELEASE for data summary and goodness—of—fit tests and SURGE for iterative model fitting and the computation of likelihood ratio tests. Five increasingly complex examples are given to illustrate the theory. The first, using two data sets on the European Dipper (Cinclus cinclus), tests for sex—specific parameters, explores a model with time—dependent survival rates, and finally uses a priori information to model survival allowing for an environmental variable. The second uses data on two colonies of the Swift (Apus apus), and shows how interaction terms can be modeled and assessed and how survival and recapture rates sometimes partly counterbalance each other. The third shows complex variation in survival rates across sexes and age classes in the roe deer (Capreolus capreolus), with a test of density dependence in annual survival rates. The fourth is an example of experimental density manipulation using the common lizard (Lacerta vivipara). The last example attempts to examine a large and complex data set on the Greater Flamingo (Phoenicopterus ruber), where parameters are age specific, survival is a function of an environmental variable, and an age × year interaction term is important. Heterogeneity seems present in this example and cannot be adequately modeled with existing theory. The discussion presents a summary of the paradigm we recommend and details issues in model selection and design, and foreseeable future developments.

@article{doi1023072937171,
    author = "Lebreton, Jean‐Dominique and Burnham, Kenneth P. and Clobert, Jean and Anderson, David R.",
    title = "Modeling Survival and Testing Biological Hypotheses Using Marked Animals: A Unified Approach with Case Studies",
    year = "1992",
    journal = "Ecological Monographs",
    abstract = {The understanding of the dynamics of animal populations and of related ecological and evolutionary issues frequently depends on a direct analysis of life history parameters. For instance, examination of trade—offs between reproduction and survival usually rely on individually marked animals, for which the exact time of death is most often unknown, because marked individuals cannot be followed closely through time. Thus, the quantitative analysis of survival studies and experiments must be based on capture—recapture (or resighting) models which consider, besides the parameters of primary interest, recapture or resighting rates that are nuisance parameters. Capture—recapture models oriented to estimation of survival rates are the result of a recent change in emphasis from earlier approaches in which population size was the most important parameter, survival rates having been first introduced as nuisance parameters. This emphasis on survival rates in capture—recapture models developed rapidly in the 1980s and used as a basic structure the Cormack—Jolly—Seber survival model applied to an homogeneous group of animals, with various kinds of constraints on the model parameters. These approaches are conditional on first captures; hence they do not attempt to model the initial capture of unmarked animals as functions of population abundance in addition to survival and capture probabilities. This paper synthesizes, using a common framework, these recent developments together with new ones, with an emphasis on flexibility in modeling, model selection, and the analysis of multiple data sets. The effects on survival and capture rates of time, age, and categorical variables characterizing the individuals (e.g., sex) can be considered, as well as interactions between such effects. This "analysis of variance" philosophy emphasizes the structure of the survival and capture process rather than the technical characteristics of any particular model. The flexible array of models encompassed in this synthesis uses a common notation. As a result of the great level of flexibility and relevance achieved, the focus is changed from fitting a particular model to model building and model selection. The following procedure is recommended: (1) start from a global model compatible with the biology of the species studied and with the design of the study, and assess its fit; (2) select a more parsimonious model using Akaike's Information Criterion to limit the number of formal tests; (3) test for the most important biological questions by comparing this model with neighboring ones using likelihood ratio tests; and (4) obtain maximum likelihood estimates of model parameters with estimates of precision. Computer software is critical, as few of the models now available have parameter estimators that are in closed form. A comprehensive table of existing computer software is provided. We used RELEASE for data summary and goodness—of—fit tests and SURGE for iterative model fitting and the computation of likelihood ratio tests. Five increasingly complex examples are given to illustrate the theory. The first, using two data sets on the European Dipper (Cinclus cinclus), tests for sex—specific parameters, explores a model with time—dependent survival rates, and finally uses a priori information to model survival allowing for an environmental variable. The second uses data on two colonies of the Swift (Apus apus), and shows how interaction terms can be modeled and assessed and how survival and recapture rates sometimes partly counterbalance each other. The third shows complex variation in survival rates across sexes and age classes in the roe deer (Capreolus capreolus), with a test of density dependence in annual survival rates. The fourth is an example of experimental density manipulation using the common lizard (Lacerta vivipara). The last example attempts to examine a large and complex data set on the Greater Flamingo (Phoenicopterus ruber), where parameters are age specific, survival is a function of an environmental variable, and an age × year interaction term is important. Heterogeneity seems present in this example and cannot be adequately modeled with existing theory. The discussion presents a summary of the paradigm we recommend and details issues in model selection and design, and foreseeable future developments.},
    url = "https://doi.org/10.2307/2937171",
    doi = "10.2307/2937171",
    openalex = "W2047495451",
    references = "doi101198tech2005s303, doi1023071232, doi1023071942661"
}

The populations of many species of animals and plants are age-structured, i.e. the individuals present at any one time were born over a range of different times, and their fertility and survival depend on age. The properties of such populations are important for interpreting experiments and observations on the genetics of populations for animal and plant breeding, and for understanding the evolution of features of life-histories such as senescence and time of reproduction. In this new edition Brian Charlesworth provides a comprehensive review of the basic mathematical theory of the demography and genetics of age-structured populations. The mathematical level of the book is such that it will be accessible to anyone with a knowledge of basic calculus and linear algebra.

@book{doi101017cbo9780511525711,
    author = "Charlesworth, Brian",
    title = "Evolution in Age-Structured Populations",
    year = "1994",
    booktitle = "Cambridge University Press eBooks",
    abstract = "The populations of many species of animals and plants are age-structured, i.e. the individuals present at any one time were born over a range of different times, and their fertility and survival depend on age. The properties of such populations are important for interpreting experiments and observations on the genetics of populations for animal and plant breeding, and for understanding the evolution of features of life-histories such as senescence and time of reproduction. In this new edition Brian Charlesworth provides a comprehensive review of the basic mathematical theory of the demography and genetics of age-structured populations. The mathematical level of the book is such that it will be accessible to anyone with a knowledge of basic calculus and linear algebra.",
    url = "https://doi.org/10.1017/cbo9780511525711",
    doi = "10.1017/cbo9780511525711",
    openalex = "W4299787297"
}

Human impacts obviously have reduced or eliminated many populations of am- phibians and other organisms. Recent reports, however, have suggested that declines and disap- pearances of amphibian populations over the last two decades represent a distinct phenomenon that goes beyond this general biodiversity crisis. We review the literature on natural temporal and spatial variation in population sizes and examine techniques for analyzing trends in abundance. Whether the recent declines and extinctions of isolated, protected amphibian populations exceed expected natural fluctuations remains equivocal. The suggestion that amphibians are particularly sensitive bioindicators of anthropogenic stresses has not received adequate study, and to our knowl- edge, no evidence has been presented to substantiate it. Although concern about the status of amphibian populations is clearly warranted, formulation of appropriate null hypotheses and further study are needed.

@article{openalexw146734964,
    author = "Pechmann, Joseph H. K. and Wilbur, Henry M. and Drawer, E",
    title = "PUTTING DECLINING AMPHIBIAN POPULATIONS IN PERSPECTIVE: NATURAL FLUCTUATIONS AND HUMAN IMPACTS",
    year = "1994",
    abstract = "Human impacts obviously have reduced or eliminated many populations of am- phibians and other organisms. Recent reports, however, have suggested that declines and disap- pearances of amphibian populations over the last two decades represent a distinct phenomenon that goes beyond this general biodiversity crisis. We review the literature on natural temporal and spatial variation in population sizes and examine techniques for analyzing trends in abundance. Whether the recent declines and extinctions of isolated, protected amphibian populations exceed expected natural fluctuations remains equivocal. The suggestion that amphibians are particularly sensitive bioindicators of anthropogenic stresses has not received adequate study, and to our knowl- edge, no evidence has been presented to substantiate it. Although concern about the status of amphibian populations is clearly warranted, formulation of appropriate null hypotheses and further study are needed.",
    openalex = "W146734964",
    references = "doi101098rstb19900188"
}

The populations of many species of animals and plants are age-structured, i.e. the individuals present at any one time were born over a range of different times, and their fertility and survival depend on age. The properties of such populations are important for interpreting experiments and observations on the genetics of populations for animal and plant breeding, and for understanding the evolution of features of life-histories such as senescence and time of reproduction. In this new edition Brian Charlesworth provides a comprehensive review of the basic mathematical theory of the demography and genetics of age-structured populations. The mathematical level of the book is such that it will be accessible to anyone with a knowledge of basic calculus and linear algebra.

@article{doi105860choice323873,
    author = "Charlesworth, Brian 1945-",
    title = "Evolution in age-structured populations",
    year = "1995",
    journal = "Choice Reviews Online",
    abstract = "The populations of many species of animals and plants are age-structured, i.e. the individuals present at any one time were born over a range of different times, and their fertility and survival depend on age. The properties of such populations are important for interpreting experiments and observations on the genetics of populations for animal and plant breeding, and for understanding the evolution of features of life-histories such as senescence and time of reproduction. In this new edition Brian Charlesworth provides a comprehensive review of the basic mathematical theory of the demography and genetics of age-structured populations. The mathematical level of the book is such that it will be accessible to anyone with a knowledge of basic calculus and linear algebra.",
    url = "https://doi.org/10.5860/choice.32-3873",
    doi = "10.5860/choice.32-3873",
    openalex = "W1579114536"
}

Abstract MARK provides parameter estimates from marked animals when they are re-encountered at a later time as dead recoveries, or live recaptures or re-sightings. The time intervals between re-encounters do not have to be equal. More than one attribute group of animals can be modelled. The basic input to MARK is the encounter history for each animal. MARK can also estimate the size of closed populations. Parameters can be constrained to be the same across re-encounter occasions, or by age, or group, using the parameter index matrix. A set of common models for initial screening of data are provided. Time effects, group effects, time x group effects and a null model of none of the above, are provided for each parameter. Besides the logit function to link the design matrix to the parameters of the model, other link functions include the log—log, complimentary log—log, sine, log, and identity. The estimates of model parameters are computed via numerical maximum likelihood techniques. The number of parameters that are estimable in the model are determined numerically and used to compute the quasi-likelihood AIC value for the model. Both the input data, and outputs for various models that the user has built, are stored in the Results database which contains a complete description of the model building process. It is viewed and manipulated in a Results Browser window. Summaries available from this window include viewing and printing model output, deviance residuals from the model, likelihood ratio and analysis of deviance between models, and adjustments for over dispersion. Models can also be retrieved and modified to create additional models. These capabilities are implemented in a Microsoft Windows 95 interface. The online help system has been developed to provide all necessary program documentation.

@article{doi10108000063659909477239,
    author = "White, Gary C. and Burnham, Kenneth P.",
    title = "Program MARK: survival estimation from populations of marked animals",
    year = "1999",
    journal = "Bird Study",
    abstract = "Abstract MARK provides parameter estimates from marked animals when they are re-encountered at a later time as dead recoveries, or live recaptures or re-sightings. The time intervals between re-encounters do not have to be equal. More than one attribute group of animals can be modelled. The basic input to MARK is the encounter history for each animal. MARK can also estimate the size of closed populations. Parameters can be constrained to be the same across re-encounter occasions, or by age, or group, using the parameter index matrix. A set of common models for initial screening of data are provided. Time effects, group effects, time x group effects and a null model of none of the above, are provided for each parameter. Besides the logit function to link the design matrix to the parameters of the model, other link functions include the log—log, complimentary log—log, sine, log, and identity. The estimates of model parameters are computed via numerical maximum likelihood techniques. The number of parameters that are estimable in the model are determined numerically and used to compute the quasi-likelihood AIC value for the model. Both the input data, and outputs for various models that the user has built, are stored in the Results database which contains a complete description of the model building process. It is viewed and manipulated in a Results Browser window. Summaries available from this window include viewing and printing model output, deviance residuals from the model, likelihood ratio and analysis of deviance between models, and adjustments for over dispersion. Models can also be retrieved and modified to create additional models. These capabilities are implemented in a Microsoft Windows 95 interface. The online help system has been developed to provide all necessary program documentation.",
    url = "https://doi.org/10.1080/00063659909477239",
    doi = "10.1080/00063659909477239",
    openalex = "W2133371793",
    references = "doi10100703872725509, doi1010079781489932426, doi101093biomet5212225, doi101093biomet613439, doi1023072290358, doi1023072531423, doi1023072531565, doi1023072532321, doi1023072937171, openalexw2262954636"
}

We define seed limitation to be an increase in population size following seed addition. Here, we briefly consider how theoretical models deal with seed limitation and how seed sowing experiments can be used to unravel the extent of seed limitation in natural systems. We review two types of seed addition experiments: seed augmentation studies where seeds are added to existing populations; and seed introductions where seeds are sown in unoccupied sites. Overall, approximately 50% of seed augmentation experiments show evidence of seed limitation. These studies show that seed limitation tends to occur more commonly in early successional habitats and in early successional species. Most of the studies have concentrated on simply categorising populations as seed‐ or microsite‐limited, but we believe that seed sowing experiments could be used to reveal much more about community structure, and we discuss possible future directions. In 53% of introduction studies (where seeds were sown at sites from which the species was known to be absent) the introduced species was recorded in at least one of the experimental sites following sowing. However, of the subset of studies where both seedlings and adult plants were recorded, 64% of sites contained seedlings while only 23% contained adults. This implies that, for many species, conditions for establishment are more stringent than conditions for germination. The successful establishment of plants in unoccupied patches indicates the potential for immigration to enhance local diversity (the spatial mass effect). Few studies continued monitoring for long enough to determine whether or not self‐sustaining populations were successfully established, and no study attempted to link introduction sites to a putative natural source of propagules, or considered the dynamics of the metapopulation as a whole.

@article{doi101034j160007062000880201x,
    author = "Turnbull, Lindsay A. and Crawley, Michael J. and Rees, Mark",
    title = "Are plant populations seed‐limited? A review of seed sowing experiments",
    year = "2000",
    journal = "Oikos",
    abstract = "We define seed limitation to be an increase in population size following seed addition. Here, we briefly consider how theoretical models deal with seed limitation and how seed sowing experiments can be used to unravel the extent of seed limitation in natural systems. We review two types of seed addition experiments: seed augmentation studies where seeds are added to existing populations; and seed introductions where seeds are sown in unoccupied sites. Overall, approximately 50\% of seed augmentation experiments show evidence of seed limitation. These studies show that seed limitation tends to occur more commonly in early successional habitats and in early successional species. Most of the studies have concentrated on simply categorising populations as seed‐ or microsite‐limited, but we believe that seed sowing experiments could be used to reveal much more about community structure, and we discuss possible future directions. In 53\% of introduction studies (where seeds were sown at sites from which the species was known to be absent) the introduced species was recorded in at least one of the experimental sites following sowing. However, of the subset of studies where both seedlings and adult plants were recorded, 64\% of sites contained seedlings while only 23\% contained adults. This implies that, for many species, conditions for establishment are more stringent than conditions for germination. The successful establishment of plants in unoccupied patches indicates the potential for immigration to enhance local diversity (the spatial mass effect). Few studies continued monitoring for long enough to determine whether or not self‐sustaining populations were successfully established, and no study attempted to link introduction sites to a putative natural source of propagules, or considered the dynamics of the metapopulation as a whole.",
    url = "https://doi.org/10.1034/j.1600-0706.2000.880201.x",
    doi = "10.1034/j.1600-0706.2000.880201.x",
    openalex = "W2113064437",
    references = "doi101111j109583121991tb00552x"
}

Knowledge of population growth potential is crucial for studying population dynamics and for establishing management tactics for pest control. Estimation of population growth can be achieved with fertility life tables because they synthesize data on reproduction and mortality of a population. The five main parameters associated with a fertility life table are as follows: (1) the net reproductive rate (Ro), (2) the intrinsic rate of increase (rm), 3) the mean generation time (T), (4) the doubling time (Dt), and (5) the finite rate of increase (lambda). Jackknife and bootstrap techniques are used to calculate the variance of the rm estimate, which can be extended to the other parameters of life tables. Those methods are computer-intensive, their application requires the development of efficient algorithms, and their implementation is based on a programming language that encompasses quickness and reliability. The objectives of this article are to discuss statistical and computational aspects related to estimation of life table parameters and to present a SAS program that uses jackknife to estimate parameters for fertility life tables. The SAS program presented here allows the calculation of confidence intervals for all estimated parameters, as well as provides one-sided and two-sided t-tests to perform pairwise or multiple comparison between groups, with their respective P values.

@article{doi10160300220493932511,
    author = "de H. N. Maia, A. and Luiz, Alfredo José Barreto and Campânhola, Clayton",
    title = "Statistical Inference on Associated Fertility Life Table Parameters Using Jackknife Technique: Computational Aspects",
    year = "2000",
    journal = "Journal of Economic Entomology",
    abstract = "Knowledge of population growth potential is crucial for studying population dynamics and for establishing management tactics for pest control. Estimation of population growth can be achieved with fertility life tables because they synthesize data on reproduction and mortality of a population. The five main parameters associated with a fertility life table are as follows: (1) the net reproductive rate (Ro), (2) the intrinsic rate of increase (rm), 3) the mean generation time (T), (4) the doubling time (Dt), and (5) the finite rate of increase (lambda). Jackknife and bootstrap techniques are used to calculate the variance of the rm estimate, which can be extended to the other parameters of life tables. Those methods are computer-intensive, their application requires the development of efficient algorithms, and their implementation is based on a programming language that encompasses quickness and reliability. The objectives of this article are to discuss statistical and computational aspects related to estimation of life table parameters and to present a SAS program that uses jackknife to estimate parameters for fertility life tables. The SAS program presented here allows the calculation of confidence intervals for all estimated parameters, as well as provides one-sided and two-sided t-tests to perform pairwise or multiple comparison between groups, with their respective P values.",
    url = "https://doi.org/10.1603/0022-0493-93.2.511",
    doi = "10.1603/0022-0493-93.2.511",
    openalex = "W2176902923",
    references = "birch1948the, doi101007978940091225010, doi10108001621459196710482935, doi101093jee8851089, doi101111j143904181994tb00767x, doi101111j174473481953tb02372x, doi10113719781611970319, doi1023071938671, doi1023072289268, doi1023073495274"
}

Abstract – Among the species in the family Salmonidae, those represented by the genera Salmo, Salvelinus, and Oncorhynchus (subfamily Salmoninae) are the most studied. Here, various aspects of phenotypic and life‐history variation of Atlantic salmon Salmo salar L., brown trout Salmo trutta L., and Arctic charr Salvelinus alpinus (L.) are reviewed. While many strategies and tactics are commonly used by these species, there are also differences in their ecology and population dynamics that result in a variety of interesting and diverse topics that are challenging for future research. Atlantic salmon display considerable phenotypic plasticity and variability in life‐history characters ranging from fully freshwater resident forms, where females can mature at approximately 10 cm in length, to anadromous populations characterised by 3–5 sea‐winter (5SW) salmon. Even within simple 1SW populations, 20 or more spawning life‐history types can be identified. Juveniles in freshwater can use both fluvial and lacustrine habitats for rearing, and while most smolts migrate to sea during the spring, fall migrations occur in some populations. At sea, some salmon undertake extensive oceanic migrations while other populations stay within the geographical confines of areas such as the Baltic Sea. At the other extreme are those that reside in estuaries and return to freshwater to spawn after spending only a few months at sea. The review of information on the diversity of life‐history forms is related to conservation aspects associated with Atlantic salmon populations and current trends in abundance and survival. Brown trout is indigenous to Europe, North Africa and western Asia, but was introduced into at least 24 countries outside Europe and now has a world‐wide distribution. It exploits both fresh and salt waters for feeding and spawning (brackish), and populations are often partially migratory. One part of the population leaves and feeds elsewhere, while another part stays as residents. In large, complex systems, the species is polymorphic with different size morphs in the various parts of the habitat. Brown trout feed close to the surface and near shore, but large individuals may move far offshore. The species exhibits ontogenetic niche shifts partly related to size and partly to developmental rate. They switch when the amount of surplus energy available for growth becomes small with fast growers being younger and smaller fish than slow growers. Brown trout is an opportunistic carnivore, but individuals specialise at least temporarily on particular food items; insect larvae are important for the young in streams, while littoral epibenthos in lakes and fish are most important for large trout. The sexes differ in resource use and size. Females are more inclined than males to become migratory and feed in pelagic waters. Males exploit running water, near‐shore and surface waters more than females. Therefore, females feed more on zooplankton and exhibit a more uniform phenotype than males. The Arctic charr is the northernmost freshwater fish on earth, with a circumpolar distribution in the Holarctic that matches the last glaciation. Recent mtDNA studies indicate that there are five phylogeographic lineages (Atlantic, Arctic, Bering, Siberian and Acadian) that may be of Pleistocene origin. Phenotypic expression and ecology are more variable in charr than in most fish. Weights at maturation range from 3 g to 12 kg. Population differences in morphology and coloration are large and can have some genetic basis. Charr live in streams, at sea and in all habitats of oligotrophic lakes, including very deep areas. Ontogenetic habitat shifts between lacustrine habitats are common. The charr feed on all major prey types of streams, lakes and near‐shore marine habitats, but has high niche flexibility in competition. Cannibalism is expressed in several cases, and can be important for developing and maintaining bimodal size distributions. Anadromy is found in the northern part of its range and involves about 40, but sometimes more days in the sea. All charr overwinter in freshwater. Partial migration is common, but the degree of anadromy varies greatly among populations. The food at sea includes zooplankton and pelagic fish, but also epibenthos. Polymorphism and sympatric morphs are much studied. As a prominent fish of glaciated lakes, charr is an important species for studying ecological speciation by the combination of field studies and experiments, particularly in the fields of morphometric heterochrony and comparative behaviour.

@article{doi101034j16000633200300010x,
    author = "Klemetsen, Anders and Amundsen, Per‐Arne and Dempson, J. Brian and Jönsson, Bror and Jönsson, Nina and O’Connell, Michael and Mortensen, Erik Lykke",
    title = "Atlantic salmon Salmo salar L., brown trout Salmo trutta L. and Arctic charr Salvelinus alpinus (L.): a review of aspects of their life histories",
    year = "2003",
    journal = "Ecology Of Freshwater Fish",
    abstract = "Abstract – Among the species in the family Salmonidae, those represented by the genera Salmo, Salvelinus, and Oncorhynchus (subfamily Salmoninae) are the most studied. Here, various aspects of phenotypic and life‐history variation of Atlantic salmon Salmo salar L., brown trout Salmo trutta L., and Arctic charr Salvelinus alpinus (L.) are reviewed. While many strategies and tactics are commonly used by these species, there are also differences in their ecology and population dynamics that result in a variety of interesting and diverse topics that are challenging for future research. Atlantic salmon display considerable phenotypic plasticity and variability in life‐history characters ranging from fully freshwater resident forms, where females can mature at approximately 10 cm in length, to anadromous populations characterised by 3–5 sea‐winter (5SW) salmon. Even within simple 1SW populations, 20 or more spawning life‐history types can be identified. Juveniles in freshwater can use both fluvial and lacustrine habitats for rearing, and while most smolts migrate to sea during the spring, fall migrations occur in some populations. At sea, some salmon undertake extensive oceanic migrations while other populations stay within the geographical confines of areas such as the Baltic Sea. At the other extreme are those that reside in estuaries and return to freshwater to spawn after spending only a few months at sea. The review of information on the diversity of life‐history forms is related to conservation aspects associated with Atlantic salmon populations and current trends in abundance and survival. Brown trout is indigenous to Europe, North Africa and western Asia, but was introduced into at least 24 countries outside Europe and now has a world‐wide distribution. It exploits both fresh and salt waters for feeding and spawning (brackish), and populations are often partially migratory. One part of the population leaves and feeds elsewhere, while another part stays as residents. In large, complex systems, the species is polymorphic with different size morphs in the various parts of the habitat. Brown trout feed close to the surface and near shore, but large individuals may move far offshore. The species exhibits ontogenetic niche shifts partly related to size and partly to developmental rate. They switch when the amount of surplus energy available for growth becomes small with fast growers being younger and smaller fish than slow growers. Brown trout is an opportunistic carnivore, but individuals specialise at least temporarily on particular food items; insect larvae are important for the young in streams, while littoral epibenthos in lakes and fish are most important for large trout. The sexes differ in resource use and size. Females are more inclined than males to become migratory and feed in pelagic waters. Males exploit running water, near‐shore and surface waters more than females. Therefore, females feed more on zooplankton and exhibit a more uniform phenotype than males. The Arctic charr is the northernmost freshwater fish on earth, with a circumpolar distribution in the Holarctic that matches the last glaciation. Recent mtDNA studies indicate that there are five phylogeographic lineages (Atlantic, Arctic, Bering, Siberian and Acadian) that may be of Pleistocene origin. Phenotypic expression and ecology are more variable in charr than in most fish. Weights at maturation range from 3 g to 12 kg. Population differences in morphology and coloration are large and can have some genetic basis. Charr live in streams, at sea and in all habitats of oligotrophic lakes, including very deep areas. Ontogenetic habitat shifts between lacustrine habitats are common. The charr feed on all major prey types of streams, lakes and near‐shore marine habitats, but has high niche flexibility in competition. Cannibalism is expressed in several cases, and can be important for developing and maintaining bimodal size distributions. Anadromy is found in the northern part of its range and involves about 40, but sometimes more days in the sea. All charr overwinter in freshwater. Partial migration is common, but the degree of anadromy varies greatly among populations. The food at sea includes zooplankton and pelagic fish, but also epibenthos. Polymorphism and sympatric morphs are much studied. As a prominent fish of glaciated lakes, charr is an important species for studying ecological speciation by the combination of field studies and experiments, particularly in the fields of morphometric heterochrony and comparative behaviour.",
    url = "https://doi.org/10.1034/j.1600-0633.2003.00010.x",
    doi = "10.1034/j.1600-0633.2003.00010.x",
    openalex = "W2165742276",
    references = "doi101007978146847862422, doi101007bf00042661, doi101017cbo9780511806292, doi101086285558, doi101086409052, doi101111j109583121996tb01434x, doi101126science150369228, doi101146annurevecolsys151393, doi101146annureves15110184002141, doi1023071442619, doi1023071935217, doi1023075403, openalexw2040817479"
}

@article{doi101016janbehav200505010,
    author = "Blumstein, Daniel T.",
    title = "Developing an evolutionary ecology of fear: how life history and natural history traits affect disturbance tolerance in birds",
    year = "2006",
    journal = "Animal Behaviour",
    url = "https://doi.org/10.1016/j.anbehav.2005.05.010",
    doi = "10.1016/j.anbehav.2005.05.010",
    openalex = "W2135732239",
    references = "doi10108003115510408619286, doi101086415838, doi105751es00404060111"
}

Abstract Life history data for Aphidius gifuensis (Ashmead) and Myzus persicae (Sulzer) were collected in the laboratory. To consider both sexes and variable developmental rates among individuals, the raw data were analyzed using the age-stage, two-sex life table. The intrinsic rate of increase (r) for A. gifuensis is 0.264 d−1. The mean parasitism rate is 92.3 aphids per female. The intrinsic rate of increase for M. persicae is 0.252 d−1. For applying the female age-specific life table to a female population, we prove that the relationship between the mean female fecundity (F) and the net reproductive rate (R0) is R0 = saF, where sa is the preadult survival rate. When the female age-specific life table is applied to two-sex populations, the relationship between F and R0 is R0 = sawF, where sa is the preadult survival rate of females, and w is the female proportion in offspring. This is valid when w is a constant for the age-specific fecundity (mx) of all ages. Because sexing preadult individuals is difficult, and obtaining a constant sex ratio in offspring is uncertain, determining preadult mortality of the individual sexes may be problematical. As a result, calculations of the age-specific survival rate (lx) and fecundity and population parameters may be adversely affected. Moreover, if lx and mx are constructed based on adult age, they may also cause errors in population parameters. Because the application of female age-specific life table to stage-structured bisexual population results in inaccuracies, we recommend that the age-stage, two-sex life table should be used in insect demographic studies.

@article{doi1016030046225x35110,
    author = "Chı, Hsin and Su, Haw-Yuan",
    title = "Age-Stage, Two-Sex Life Tables of Aphidius gifuensis (Ashmead) (Hymenoptera: Braconidae) and Its Host Myzus persicae (Sulzer) (Homoptera: Aphididae) with Mathematical Proof of the Relationship Between Female Fecundity and the Net Reproductive Rate",
    year = "2006",
    journal = "Environmental Entomology",
    abstract = "Abstract Life history data for Aphidius gifuensis (Ashmead) and Myzus persicae (Sulzer) were collected in the laboratory. To consider both sexes and variable developmental rates among individuals, the raw data were analyzed using the age-stage, two-sex life table. The intrinsic rate of increase (r) for A. gifuensis is 0.264 d−1. The mean parasitism rate is 92.3 aphids per female. The intrinsic rate of increase for M. persicae is 0.252 d−1. For applying the female age-specific life table to a female population, we prove that the relationship between the mean female fecundity (F) and the net reproductive rate (R0) is R0 = saF, where sa is the preadult survival rate. When the female age-specific life table is applied to two-sex populations, the relationship between F and R0 is R0 = sawF, where sa is the preadult survival rate of females, and w is the female proportion in offspring. This is valid when w is a constant for the age-specific fecundity (mx) of all ages. Because sexing preadult individuals is difficult, and obtaining a constant sex ratio in offspring is uncertain, determining preadult mortality of the individual sexes may be problematical. As a result, calculations of the age-specific survival rate (lx) and fecundity and population parameters may be adversely affected. Moreover, if lx and mx are constructed based on adult age, they may also cause errors in population parameters. Because the application of female age-specific life table to stage-structured bisexual population results in inaccuracies, we recommend that the age-stage, two-sex life table should be used in insect demographic studies.",
    url = "https://doi.org/10.1603/0046-225x-35.1.10",
    doi = "10.1603/0046-225x-35.1.10",
    openalex = "W2172660955",
    references = "birch1948the, doi101007978364281046625, doi101017cbo9780511525711, doi101086283956, doi101093biomet333183, doi101093ee17126, doi1023072289268, doi1023073280305, openalexw1497099219, openalexw2182110386"
}

The life tables of Hypothenemus hampei were elaborated and compared on the coffee accessions Coffea liberica, Coffea arabica CCC 534 and the susceptible variety Caturra, in order to find sources of resistance to this insect under controlled conditions (26°C ± 1, 75% ± 5 R. H.). Two assays were performed: in the first, the development of the immature stages was followed and survival was estimated. In the second, adult survival and fecundity were determined using 36- day old females. The duration of the cycle for CCC 534, C. liberica and Caturra was similar: total 20 days, egg four, first instar four, second instar six, prepupa two and pupa four days, approximately. The number of accumulated eggs in the three accessions fit quadratic functions. The confidence intervals (95%) showed significant differences between the accessions and the control: CCC 534 32 ± 2, C. liberica 28 ± 2 and Caturra 42 ± 2 eggs per female. The sex ratios were 9.2, 9.8, and 9.8 male: female, respectively. There was no difference in survival (range 58-63%) up to 72 days for the three accessions. There were differences in the net reproductive rate (Ro) among Caturra (25 ± 1 eggs), CCC 534 (18 ± 2), and C. liberica (15 ± 2); in the intrinsic rate of increase (r) (0.073 ± 0.001, 0.065 ± 0.002, 0.057 ± 0.003, respectively), and the duplication time (10 ± 0.2, 11 ± 0.4, 12 ± 0.6 days). In the generation time there was only a differences between Caturra and C. liberica (45 ± 0.4, 47 ± 0.8, respectively).

@article{doi1025100socolenv33i19308,
    author = "Romero, Juan Vicente and CORTINA-G., HERNANDO ALFONSO",
    title = "Life Tables of Hypothenemus Hampei (Coleoptera: Curculionidae: Scolytinae) On Three Coffee Accessions",
    year = "2007",
    journal = "Revista Colombiana de Entomología",
    abstract = "The life tables of Hypothenemus hampei were elaborated and compared on the coffee accessions Coffea liberica, Coffea arabica CCC 534 and the susceptible variety Caturra, in order to find sources of resistance to this insect under controlled conditions (26°C ± 1, 75\% ± 5 R. H.). Two assays were performed: in the first, the development of the immature stages was followed and survival was estimated. In the second, adult survival and fecundity were determined using 36- day old females. The duration of the cycle for CCC 534, C. liberica and Caturra was similar: total 20 days, egg four, first instar four, second instar six, prepupa two and pupa four days, approximately. The number of accumulated eggs in the three accessions fit quadratic functions. The confidence intervals (95\%) showed significant differences between the accessions and the control: CCC 534 32 ± 2, C. liberica 28 ± 2 and Caturra 42 ± 2 eggs per female. The sex ratios were 9.2, 9.8, and 9.8 male: female, respectively. There was no difference in survival (range 58-63\%) up to 72 days for the three accessions. There were differences in the net reproductive rate (Ro) among Caturra (25 ± 1 eggs), CCC 534 (18 ± 2), and C. liberica (15 ± 2); in the intrinsic rate of increase (r) (0.073 ± 0.001, 0.065 ± 0.002, 0.057 ± 0.003, respectively), and the duplication time (10 ± 0.2, 11 ± 0.4, 12 ± 0.6 days). In the generation time there was only a differences between Caturra and C. liberica (45 ± 0.4, 47 ± 0.8, respectively).",
    url = "https://doi.org/10.25100/socolen.v33i1.9308",
    doi = "10.25100/socolen.v33i1.9308",
    openalex = "W1603597367",
    references = "birch1948the, deevey1947life, doi10100797836423585869, doi101093aesa492190, doi101146annureven14010169001135, doi1012019781420058376, doi10160300220493932511, doi1023073798722, doi1023074510986, openalexw1500291103, smith2013life"
}

A fundamental but unanswered biological question asks how much energy, on average, Earth's different life forms spend per unit mass per unit time to remain alive. Here, using the largest database to date, for 3,006 species that includes most of the range of biological diversity on the planet-from bacteria to elephants, and algae to sapling trees-we show that metabolism displays a striking degree of homeostasis across all of life. We demonstrate that, despite the enormous biochemical, physiological, and ecological differences between the surveyed species that vary over 10(20)-fold in body mass, mean metabolic rates of major taxonomic groups displayed at physiological rest converge on a narrow range from 0.3 to 9 W kg(-1). This 30-fold variation among life's disparate forms represents a remarkably small range compared with the 4,000- to 65,000-fold difference between the mean metabolic rates of the smallest and largest organisms that would be observed if life as a whole conformed to universal quarter-power or third-power allometric scaling laws. The observed broad convergence on a narrow range of basal metabolic rates suggests that organismal designs that fit in this physiological window have been favored by natural selection across all of life's major kingdoms, and that this range might therefore be considered as optimal for living matter as a whole.

@article{doi101073pnas0802148105,
    author = "Makarieva, Anastassia M. and Gorshkov, V. G. and Li, Bai-Lian and Chown, Steven L. and Reich, Peter B. and Гаврилов, В. М.",
    title = "Mean mass-specific metabolic rates are strikingly similar across life's major domains: Evidence for life's metabolic optimum",
    year = "2008",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = "A fundamental but unanswered biological question asks how much energy, on average, Earth's different life forms spend per unit mass per unit time to remain alive. Here, using the largest database to date, for 3,006 species that includes most of the range of biological diversity on the planet-from bacteria to elephants, and algae to sapling trees-we show that metabolism displays a striking degree of homeostasis across all of life. We demonstrate that, despite the enormous biochemical, physiological, and ecological differences between the surveyed species that vary over 10(20)-fold in body mass, mean metabolic rates of major taxonomic groups displayed at physiological rest converge on a narrow range from 0.3 to 9 W kg(-1). This 30-fold variation among life's disparate forms represents a remarkably small range compared with the 4,000- to 65,000-fold difference between the mean metabolic rates of the smallest and largest organisms that would be observed if life as a whole conformed to universal quarter-power or third-power allometric scaling laws. The observed broad convergence on a narrow range of basal metabolic rates suggests that organismal designs that fit in this physiological window have been favored by natural selection across all of life's major kingdoms, and that this range might therefore be considered as optimal for living matter as a whole.",
    url = "https://doi.org/10.1073/pnas.0802148105",
    doi = "10.1073/pnas.0802148105",
    openalex = "W2156702212",
    references = "doi101017s1464793105006834, doi101098rsbl20050378"
}

@article{doi101016jtree201008002,
    author = "Clutton‐Brock, Tim and Sheldon, Ben C.",
    title = "Individuals and populations: the role of long-term, individual-based studies of animals in ecology and evolutionary biology",
    year = "2010",
    journal = "Trends in Ecology \& Evolution",
    url = "https://doi.org/10.1016/j.tree.2010.08.002",
    doi = "10.1016/j.tree.2010.08.002",
    openalex = "W1973655881",
    references = "doi1010160169534787900280, doi1010160169534789900372, doi101016s0169534702024898, doi1023072404970, doi1023075465"
}

The overlap of generations of coffee berry borer (CBB), Hypothenemus hampei (Ferrari) under field conditions in countries like Colombia hinders the construction of life tables by the sampling of natural populations. In this paper, a field methodology to carry out regular measurements of CBB cohorts inside coffee berries of different ages until harvest, both in coffee trees and in infested berries placed on the ground, is developed and used to compare the life history parameters of CBB. Populations with berries at six ages in three experimental stations (without CBB control) and in a commercial farm in Colombia (with chemical CBB control regularly carried out) were used. The duration of the pre-oviposition period as well as the mortality and survival rates of founder females and the proportion of founders leaving infested berries were strongly influenced by the consistency of berries, with optimum conditions for CBB reproduction as from 120-150 days after flowering. No differences were found between stations for the number of CBB developmental stages; but they had larger values than the commercial farm. The latter also had more than twice the average rate of founders leaving infested berries recorded in the stations. Survival functions (cumulative probabilities of survival) for the pest differed among treatments and between the plant and ground micro-environments. Age of berries at infestation was positively related to the intrinsic rate of increase of borer population; whilst generation time and doubling time were inversely related. No differences were found between sites for the main demographic parameters of the pest.

@article{doi101590s010390162010000600007,
    author = "Ruiz‐Cárdenas, Ramiro and Baker, P. S.",
    title = "Life table of Hypothenemus hampei (Ferrari) in relation to coffee berry phenology under Colombian field conditions",
    year = "2010",
    journal = "Scientia Agricola",
    abstract = "The overlap of generations of coffee berry borer (CBB), Hypothenemus hampei (Ferrari) under field conditions in countries like Colombia hinders the construction of life tables by the sampling of natural populations. In this paper, a field methodology to carry out regular measurements of CBB cohorts inside coffee berries of different ages until harvest, both in coffee trees and in infested berries placed on the ground, is developed and used to compare the life history parameters of CBB. Populations with berries at six ages in three experimental stations (without CBB control) and in a commercial farm in Colombia (with chemical CBB control regularly carried out) were used. The duration of the pre-oviposition period as well as the mortality and survival rates of founder females and the proportion of founders leaving infested berries were strongly influenced by the consistency of berries, with optimum conditions for CBB reproduction as from 120-150 days after flowering. No differences were found between stations for the number of CBB developmental stages; but they had larger values than the commercial farm. The latter also had more than twice the average rate of founders leaving infested berries recorded in the stations. Survival functions (cumulative probabilities of survival) for the pest differed among treatments and between the plant and ground micro-environments. Age of berries at infestation was positively related to the intrinsic rate of increase of borer population; whilst generation time and doubling time were inversely related. No differences were found between sites for the main demographic parameters of the pest.",
    url = "https://doi.org/10.1590/s0103-90162010000600007",
    doi = "10.1590/s0103-90162010000600007",
    openalex = "W2131013958",
    references = "doi1025100socolenv33i19308"
}

Reproductive and related changes are followed for one year in two populations of the common omnivorous Antarctic asteroid Odontaster validus Koehler. At McMurdo Station, the site of one population, the fast ice breaks out late in the summer or not at all, and there is a relatively low amount of annual sunlight penetration into the sea. Twenty-two km north of McMurdo Station at Cape Evans, the other site, the fast ice breaks out in midsummer, and much more sunlight penetrates into the sea. Probably because of the higher amount of sunlight penetrating into the sea, there seems to be much more summer phytoproduction at Cape Evans than at McMurdo Station. Reflecting this probable difference in summer phytoproduction, the pyloric caeca of only the animals at Cape Evans accumulate large amounts of protein, lipid, carbohydrate, and green chlorophyll derivatives in the summer, and these animals are larger, more numerous, and more darkly pigmented than those at McMurdo Station. Samples from other sites in McMurdo Sound suggest that there is a gradation at least from the population at Cape Evans to that at McMurdo Station, and O. validus seems to be absent under the Ross Ice Shelf. One sample from Hallett Station, about 650 km north of McMurdo Station, is similar to those from Cape Evans. The animals at Cape Evans produce many more gametes than those at McMurdo Station, yet gametogenesis is similar and synchronous in the two populations. Spermatogenesis proceeds through five discrete cell stages in 7–10 months, while oögenesis takes 18–24 months and involves growth of distinct successive annual generations of primary oöcytes. In both sexes there is a more or less constant uptake of nutrients into the gonads all year, and where food fluctuates seasonally and is most abundant in the summer, as at Cape Evans, nutrients are stored in the pyloric caeca for later utilization in gametogenesis. Many oöcytes act as storage cells which further enable the ovaries to assimilate nutrients at a rather constant rate. Initiation of gametogenesis occurs between May or June and February. Because light and quantitative food changes are so different between McMurdo Station and Cape Evans, these factors probably have little effect on the synchronization of gametogenesis among individuals. Qualitative annual changes in phytoproduction or slight changes in temperature or salinity may be more important, however. Spawning occurs mainly from June to mid-September and may be synchronized by environmental changes related to low-temperature water lenses present in the midwinter. The winter spawning period of O. validus is probably an adaptation to the slow embryonic and larval developmental rates which allow the demersal bipinnaria larvae to appear during the summer phytoproduction period. The spring, winter, or fall spawning periods of many other polar species with planktotrophic larvae or young are apparently related similarly to the rates of embryonic and larval development and the summer phytoproduction period. Appended is an evaluation of a similar study made of an arctic ophiuroid, Ophiocten sericeum)Forbes).

@incollection{doi101029ar005p0039,
    author = "Pearse, John S.",
    title = "Reproductive periodicities in several contrasting populations of Odontaster Validus Koehler, A common Antarctic asteroid",
    year = "2011",
    booktitle = "Antarctic research series",
    abstract = "Reproductive and related changes are followed for one year in two populations of the common omnivorous Antarctic asteroid Odontaster validus Koehler. At McMurdo Station, the site of one population, the fast ice breaks out late in the summer or not at all, and there is a relatively low amount of annual sunlight penetration into the sea. Twenty-two km north of McMurdo Station at Cape Evans, the other site, the fast ice breaks out in midsummer, and much more sunlight penetrates into the sea. Probably because of the higher amount of sunlight penetrating into the sea, there seems to be much more summer phytoproduction at Cape Evans than at McMurdo Station. Reflecting this probable difference in summer phytoproduction, the pyloric caeca of only the animals at Cape Evans accumulate large amounts of protein, lipid, carbohydrate, and green chlorophyll derivatives in the summer, and these animals are larger, more numerous, and more darkly pigmented than those at McMurdo Station. Samples from other sites in McMurdo Sound suggest that there is a gradation at least from the population at Cape Evans to that at McMurdo Station, and O. validus seems to be absent under the Ross Ice Shelf. One sample from Hallett Station, about 650 km north of McMurdo Station, is similar to those from Cape Evans. The animals at Cape Evans produce many more gametes than those at McMurdo Station, yet gametogenesis is similar and synchronous in the two populations. Spermatogenesis proceeds through five discrete cell stages in 7–10 months, while oögenesis takes 18–24 months and involves growth of distinct successive annual generations of primary oöcytes. In both sexes there is a more or less constant uptake of nutrients into the gonads all year, and where food fluctuates seasonally and is most abundant in the summer, as at Cape Evans, nutrients are stored in the pyloric caeca for later utilization in gametogenesis. Many oöcytes act as storage cells which further enable the ovaries to assimilate nutrients at a rather constant rate. Initiation of gametogenesis occurs between May or June and February. Because light and quantitative food changes are so different between McMurdo Station and Cape Evans, these factors probably have little effect on the synchronization of gametogenesis among individuals. Qualitative annual changes in phytoproduction or slight changes in temperature or salinity may be more important, however. Spawning occurs mainly from June to mid-September and may be synchronized by environmental changes related to low-temperature water lenses present in the midwinter. The winter spawning period of O. validus is probably an adaptation to the slow embryonic and larval developmental rates which allow the demersal bipinnaria larvae to appear during the summer phytoproduction period. The spring, winter, or fall spawning periods of many other polar species with planktotrophic larvae or young are apparently related similarly to the rates of embryonic and larval development and the summer phytoproduction period. Appended is an evaluation of a similar study made of an arctic ophiuroid, Ophiocten sericeum)Forbes).",
    url = "https://doi.org/10.1029/ar005p0039",
    doi = "10.1029/ar005p0039",
    openalex = "W1588722103",
    references = "doi101017s0025315400010109"
}

Abstract Life table gives the most comprehensive description on the survival, stage differentiation and reproduction of a population and is thus the most important basis of population ecology and pest management. In this study, we constructed life tables for B actrocera cucurbitae on cucumber (C ucumis sativus L.) in the laboratory and under simulated field conditions. To assess the variability of the life tables, we carried out two experiments under each treatment. Means, variances and standard errors of life table parameters were estimated for each of the two experiments by using the jackknife technique. At 25° C, the intrinsic rates of increase (r) found for the two experiments were 0.1354 and 0.1002 per day, and the net reproductive rates (R 0) were 206.3 and 66.0 offspring, respectively. For cucumbers kept in the field and covered with leaves, the r and R 0 for the two experiments were 0.0935 and 0.0909 per day, and 17.5 and 11.4 offspring, respectively. However, if cucumbers were kept in the field but were not covered, the r and R 0 for the two experiments were 0.1043 and 0.0904 per day, and 27.7 and 10.1 offspring, respectively. Our results revealed significant variability between the experiments under both laboratory and field conditions; this variability should be taken into consideration in the data collection and application of life tables. However, our mathematical analysis shows that the application of the jackknife technique will result in biologically unrealistic R 0, i‐ pseudo and consequently overestimation of the variance of R 0. According to our analysis, we suggest that the jackknife technique should not be used for the estimation of variability of the net reproductive rate.

@article{doi101111jen12002,
    author = "Huang, Yaw‐Bin and Chı, Hsin",
    title = "Life tables of B actrocera cucurbitae (D iptera: T ephritidae): with an invalidation of the jackknife technique",
    year = "2012",
    journal = "Journal of Applied Entomology",
    abstract = "Abstract Life table gives the most comprehensive description on the survival, stage differentiation and reproduction of a population and is thus the most important basis of population ecology and pest management. In this study, we constructed life tables for B actrocera cucurbitae on cucumber (C ucumis sativus L.) in the laboratory and under simulated field conditions. To assess the variability of the life tables, we carried out two experiments under each treatment. Means, variances and standard errors of life table parameters were estimated for each of the two experiments by using the jackknife technique. At 25° C, the intrinsic rates of increase (r) found for the two experiments were 0.1354 and 0.1002 per day, and the net reproductive rates (R 0) were 206.3 and 66.0 offspring, respectively. For cucumbers kept in the field and covered with leaves, the r and R 0 for the two experiments were 0.0935 and 0.0909 per day, and 17.5 and 11.4 offspring, respectively. However, if cucumbers were kept in the field but were not covered, the r and R 0 for the two experiments were 0.1043 and 0.0904 per day, and 27.7 and 10.1 offspring, respectively. Our results revealed significant variability between the experiments under both laboratory and field conditions; this variability should be taken into consideration in the data collection and application of life tables. However, our mathematical analysis shows that the application of the jackknife technique will result in biologically unrealistic R 0, i‐ pseudo and consequently overestimation of the variance of R 0. According to our analysis, we suggest that the jackknife technique should not be used for the estimation of variability of the net reproductive rate.",
    url = "https://doi.org/10.1111/jen.12002",
    doi = "10.1111/jen.12002",
    openalex = "W2108403325",
    references = "doi10160300220493932511, doi1016030046225x35110"
}

BACKGROUND: The common cutworm, Spodoptera litura (Fabricus), is the most serious pest of peanuts in Taiwan. In order to devise an ecology-based and cost-effective control program, we collected life table data and consumption rates from larvae reared indoors at a constant temperature of 25°C, or outdoors at ambient temperatures during the spring and fall of 2010. A computer simulation was then used to project the population growth and damage potential of S. litura on peanuts. RESULTS: Laboratory-reared S. litura individuals produced 3548 eggs/female, whereas those reared outdoors produced 3452 and 3072 eggs/female in the spring and fall, respectively. The intrinsic rate of increase was 0.1828, 0.1308 and 0.1545 day(-1), and the net consumption rate was 194.0, 132.2 and 166.6 cm(2) larva(-1) at 25°C, in spring and fall, respectively. Population projection showed a faster growth and higher damage potential of S. litura in the fall. CONCLUSION: Population projections based on life tables and stage-specific consumption rates can reveal the stage structure and damage potential of the pest population. Our results showed that monitoring data obtained by using pheromone traps were not in concordance with the damage potential of the pest population. This approach offers a promising tool for pest management.

@article{doi101002ps3618,
    author = "Tuan, Shu‐Jen and Lee, Chung‐Chieh and Chı, Hsin",
    title = "Population and damage projection of Spodoptera litura (F.) on peanuts (Arachis hypogaea L.) under different conditions using the age‐stage, two‐sex life table",
    year = "2013",
    journal = "Pest Management Science",
    abstract = "BACKGROUND: The common cutworm, Spodoptera litura (Fabricus), is the most serious pest of peanuts in Taiwan. In order to devise an ecology-based and cost-effective control program, we collected life table data and consumption rates from larvae reared indoors at a constant temperature of 25°C, or outdoors at ambient temperatures during the spring and fall of 2010. A computer simulation was then used to project the population growth and damage potential of S. litura on peanuts. RESULTS: Laboratory-reared S. litura individuals produced 3548 eggs/female, whereas those reared outdoors produced 3452 and 3072 eggs/female in the spring and fall, respectively. The intrinsic rate of increase was 0.1828, 0.1308 and 0.1545 day(-1), and the net consumption rate was 194.0, 132.2 and 166.6 cm(2) larva(-1) at 25°C, in spring and fall, respectively. Population projection showed a faster growth and higher damage potential of S. litura in the fall. CONCLUSION: Population projections based on life tables and stage-specific consumption rates can reveal the stage structure and damage potential of the pest population. Our results showed that monitoring data obtained by using pheromone traps were not in concordance with the damage potential of the pest population. This approach offers a promising tool for pest management.",
    url = "https://doi.org/10.1002/ps.3618",
    doi = "10.1002/ps.3618",
    openalex = "W2093751481",
    references = "doi1016030046225x35110"
}

@incollection{doi10100797836423585869,
    author = "Smith, David P. and Keyfitz, Nathan",
    title = "Life Tables for Natural Populations of Animals",
    year = "2013",
    booktitle = "Demographic research monographs",
    url = "https://doi.org/10.1007/978-3-642-35858-6\_9",
    doi = "10.1007/978-3-642-35858-6\_9",
    openalex = "W13711907",
    references = "doi101017s0025315400010109, doi101086394476, doi101139f40008, doi1023071232, doi1023071437796, doi1023071438245, doi1023071943293, doi1023071948601, doi1023073796179, openalexw622324087"
}

@incollection{smith2013life,
    author = "Smith, David P. and Keyfitz, Nathan",
    title = "Life Tables for Natural Populations of Animals",
    year = "2013",
    booktitle = "Demographic Research Monographs",
    url = "https://doi.org/10.1007/978-3-642-35858-6\_9",
    doi = "10.1007/978-3-642-35858-6\_9",
    pages = "61-74"
}

Empirical evidence for declines in fitness components (survival and reproductive performance) with age has recently accumulated in wild populations, highlighting that the process of senescence is nearly ubiquitous in the living world. Senescence patterns are highly variable among species and current evolutionary theories of ageing propose that such variation can be accounted for by differences in allocation to growth and reproduction during early life. Here, we compiled 26 studies of free-ranging vertebrate populations that explicitly tested for a trade-off between performance in early and late life. Our review brings overall support for the presence of early-late life trade-offs, suggesting that the limitation of available resources leads individuals to trade somatic maintenance later in life for high allocation to reproduction early in life. We discuss our results in the light of two closely related theories of ageing-the disposable soma and the antagonistic pleiotropy theories-and propose that the principle of energy allocation roots the ageing process in the evolution of life-history strategies. Finally, we outline research topics that should be investigated in future studies, including the importance of natal environmental conditions in the study of trade-offs between early- and late-life performance and the evolution of sex-differences in ageing patterns.

@article{doi101098rspb20150209,
    author = "Lemaître, Jean‐François and Berger, Vérane and Bonenfant, Christophe and Douhard, Mathieu and Gamelon, Marlène and Plard, Floriane and Gaillard, Jean‐Michel",
    title = "Early-late life trade-offs and the evolution of ageing in the wild",
    year = "2015",
    journal = "Proceedings of the Royal Society B Biological Sciences",
    abstract = "Empirical evidence for declines in fitness components (survival and reproductive performance) with age has recently accumulated in wild populations, highlighting that the process of senescence is nearly ubiquitous in the living world. Senescence patterns are highly variable among species and current evolutionary theories of ageing propose that such variation can be accounted for by differences in allocation to growth and reproduction during early life. Here, we compiled 26 studies of free-ranging vertebrate populations that explicitly tested for a trade-off between performance in early and late life. Our review brings overall support for the presence of early-late life trade-offs, suggesting that the limitation of available resources leads individuals to trade somatic maintenance later in life for high allocation to reproduction early in life. We discuss our results in the light of two closely related theories of ageing-the disposable soma and the antagonistic pleiotropy theories-and propose that the principle of energy allocation roots the ageing process in the evolution of life-history strategies. Finally, we outline research topics that should be investigated in future studies, including the importance of natal environmental conditions in the study of trade-offs between early- and late-life performance and the evolution of sex-differences in ageing patterns.",
    url = "https://doi.org/10.1098/rspb.2015.0209",
    doi = "10.1098/rspb.2015.0209",
    openalex = "W2035829354",
    references = "doi101038nature12789"
}

@article{doi101038s4155901909387,
    author = "Healy, Kevin and Ezard, Thomas H. G. and Jones, Owen R. and Salguero‐Gómez, Roberto and Buckley, Yvonne M.",
    title = "Animal life history is shaped by the pace of life and the distribution of age-specific mortality and reproduction",
    year = "2019",
    journal = "Nature Ecology \& Evolution",
    url = "https://doi.org/10.1038/s41559-019-0938-7",
    doi = "10.1038/s41559-019-0938-7",
    openalex = "W2958544637",
    references = "doi101038nature12789, doi101098rsbl20050378"
}

= 290.25) and highest fecundity (544.52) occurred at 28 °C. Temperature significantly affected the intrinsic rate of increase (r), fecundity, and finite rate of increase (λ). The values of age-specific fecundity (high to low) were 28 °C > 24 °C > 30 °C > 32 °C > 22 °C, while the values of age-stage-specific fecundity had the same trend.

@article{doi103390insects11030181,
    author = "Sun, Weiwei and Cui, Miao and Xia, Liyuan and Yu, Qing and Cao, Yang and Wu, Yi",
    title = "Age-Stage, Two-Sex Life Tables of the Predatory Mite Cheyletus Malaccensis Oudemans at Different Temperatures",
    year = "2020",
    journal = "Insects",
    abstract = "= 290.25) and highest fecundity (544.52) occurred at 28 °C. Temperature significantly affected the intrinsic rate of increase (r), fecundity, and finite rate of increase (λ). The values of age-specific fecundity (high to low) were 28 °C > 24 °C > 30 °C > 32 °C > 22 °C, while the values of age-stage-specific fecundity had the same trend.",
    url = "https://doi.org/10.3390/insects11030181",
    doi = "10.3390/insects11030181",
    openalex = "W3011845569",
    references = "deevey1947life, doi101002ps3618, doi10100797836423585869, doi101016s0306456502000578, doi101093ee17126, doi101093jeetox330, doi1011111467963900050, doi101111jen12002, doi1016030046225x322327, doi1016030046225x35110, openalexw2182110386, smith2013life"
}

Abstract Life tables, which describe how the risk of death (and sometimes fertility) changes with age, are a fundamental tool for describing and exploring the diversity of life histories. Numerous important life history metrics can be derived from them. This chapter provides a broad coverage of life table construction and use and use with a particular focus on nonhuman animals. The calculation of life tables can be divided into approaches: cohort-based, where the data are obtained from individuals born at (approximately) the same time that are followed until death; and period-based, where the data are obtained from a population of mixed ages followed for a particular time-frame (e.g. a year). Worked examples of both approaches are provided using data from published sources. Emphasis is placed on understanding concepts such as rates vs. probability, life expectancy, and generation time. Links are drawn between the survivorship curve (type I, type II, and type III survivorship) and entropy. The chapter also covers the concept of the Lexis diagram which is used to represent births and deaths for individuals in different cohorts. Finally, the assumptions and limitations of life tables are discussed, with pointers to further reading. Code and data are provided.

@incollection{doi101093oso97801988386090030008,
    author = "Jones, Owen R.",
    title = "Life tables: construction and interpretation",
    year = "2021",
    abstract = "Abstract Life tables, which describe how the risk of death (and sometimes fertility) changes with age, are a fundamental tool for describing and exploring the diversity of life histories. Numerous important life history metrics can be derived from them. This chapter provides a broad coverage of life table construction and use and use with a particular focus on nonhuman animals. The calculation of life tables can be divided into approaches: cohort-based, where the data are obtained from individuals born at (approximately) the same time that are followed until death; and period-based, where the data are obtained from a population of mixed ages followed for a particular time-frame (e.g. a year). Worked examples of both approaches are provided using data from published sources. Emphasis is placed on understanding concepts such as rates vs. probability, life expectancy, and generation time. Links are drawn between the survivorship curve (type I, type II, and type III survivorship) and entropy. The chapter also covers the concept of the Lexis diagram which is used to represent births and deaths for individuals in different cohorts. Finally, the assumptions and limitations of life tables are discussed, with pointers to further reading. Code and data are provided.",
    url = "https://doi.org/10.1093/oso/9780198838609.003.0008",
    doi = "10.1093/oso/9780198838609.003.0008",
    openalex = "W3212953007",
    references = "deevey1947life, doi101007978146124380925, doi10100797836423585869, doi10108001621459195810501452, doi101093biomet333183, doi101111j251761611972tb00899x, doi101126science441136500b, doi1023071535065, doi1023072402952, doi1023072937171, doi1023075403, smith2013life"
}

Abstract The underlying current to this chapter is change. Environments are not static. They can shift directionally or exhibit natural variability, sometimes predictably (e.g. seasonal periodicity) but often unpredictably (stochasticity). The chapter begins by exploring how changes in the directionality and variance of environmental conditions can influence life-history evolution. Variability is the key word for the second half of the chapter. In response to environmental unpredictability, organisms have evolved bet-hedging strategies that maximize the geometric mean or long-run fitness. These life histories can involve one or more conservative or diversification bet-hedging traits. For example, under semelparity, selection can favour the germination of seeds or the hatching of diapausing eggs across multiple generations. Under iteroparity, rather than producing the maximum number of offspring that an organism is capable of producing in few breeding episodes, environmental variability can favour the production of fewer offspring per episode but across a greater number of breeding episodes. The chapter closes with a consideration of different forms of stochasticity and how stochastic estimates of fitness can differ from determinant estimates.

@incollection{doi101093oso97801988398730030006,
    author = "Hutchings, Jeffrey A.",
    title = "Life-History Evolution in a Changing Environment",
    year = "2021",
    abstract = "Abstract The underlying current to this chapter is change. Environments are not static. They can shift directionally or exhibit natural variability, sometimes predictably (e.g. seasonal periodicity) but often unpredictably (stochasticity). The chapter begins by exploring how changes in the directionality and variance of environmental conditions can influence life-history evolution. Variability is the key word for the second half of the chapter. In response to environmental unpredictability, organisms have evolved bet-hedging strategies that maximize the geometric mean or long-run fitness. These life histories can involve one or more conservative or diversification bet-hedging traits. For example, under semelparity, selection can favour the germination of seeds or the hatching of diapausing eggs across multiple generations. Under iteroparity, rather than producing the maximum number of offspring that an organism is capable of producing in few breeding episodes, environmental variability can favour the production of fewer offspring per episode but across a greater number of breeding episodes. The chapter closes with a consideration of different forms of stochasticity and how stochastic estimates of fitness can differ from determinant estimates.",
    url = "https://doi.org/10.1093/oso/9780198839873.003.0006",
    doi = "10.1093/oso/9780198839873.003.0006",
    openalex = "W4289718939",
    references = "doi10100797836423585869, doi101017cbo9780511806292, doi10108000063659909477239, doi101086283244, doi101086409052, doi101111j155856461957tb02911x, doi101890039000, doi1023075403, doi105860choice304983, doi105962bhltitle27468, smith2013life"
}

Abstract Demographic buffering and lability have been identified as adaptive strategies to optimise fitness in a fluctuating environment. These are not mutually exclusive, however we lack efficient methods to measure their relative importance for a given life history. Here, we decompose the stochastic growth rate (fitness) into components arising from nonlinear responses and variance-covariance of demographic parameters to an environmental driver, which allows studying joint effects of buffering and lability. We apply this decomposition for 154 animal matrix population models under different scenarios, to explore how these main fitness components vary across life histories. Faster-living species appear more responsive to environmental fluctuations, either positively or negatively. They have the highest potential for strong adaptive demographic lability, while demographic buffering is a main strategy in slow-living species. Our decomposition provides a comprehensive framework to study how organisms adapt to variability through buffering and lability, and to predict species responses to climate change.

@misc{doi10110120211209471917,
    author = "Cœur, Christie Le and Yoccoz, Nigel G. and Salguero‐Gómez, Roberto and Vindenes, Yngvild",
    title = "Life history adaptations to fluctuating environments: Combined effects of demographic buffering and lability of demographic parameters",
    year = "2021",
    booktitle = "bioRxiv (Cold Spring Harbor Laboratory)",
    abstract = "Abstract Demographic buffering and lability have been identified as adaptive strategies to optimise fitness in a fluctuating environment. These are not mutually exclusive, however we lack efficient methods to measure their relative importance for a given life history. Here, we decompose the stochastic growth rate (fitness) into components arising from nonlinear responses and variance-covariance of demographic parameters to an environmental driver, which allows studying joint effects of buffering and lability. We apply this decomposition for 154 animal matrix population models under different scenarios, to explore how these main fitness components vary across life histories. Faster-living species appear more responsive to environmental fluctuations, either positively or negatively. They have the highest potential for strong adaptive demographic lability, while demographic buffering is a main strategy in slow-living species. Our decomposition provides a comprehensive framework to study how organisms adapt to variability through buffering and lability, and to predict species responses to climate change.",
    url = "https://doi.org/10.1101/2021.12.09.471917",
    doi = "10.1101/2021.12.09.471917",
    openalex = "W4200428770",
    references = "doi101093oso97801988386090030009"
}

Demographic buffering and lability have been identified as adaptive strategies to optimise fitness in a fluctuating environment. These are not mutually exclusive, however, we lack efficient methods to measure their relative importance for a given life history. Here, we decompose the stochastic growth rate (fitness) into components arising from nonlinear responses and variance-covariance of demographic parameters to an environmental driver, which allows studying joint effects of buffering and lability. We apply this decomposition for 154 animal matrix population models under different scenarios to explore how these main fitness components vary across life histories. Faster-living species appear more responsive to environmental fluctuations, either positively or negatively. They have the highest potential for strong adaptive demographic lability, while demographic buffering is a main strategy in slow-living species. Our decomposition provides a comprehensive framework to study how organisms adapt to variability through buffering and lability, and to predict species responses to climate change.

@article{doi101111ele14071,
    author = "Cœur, Christie Le and Yoccoz, Nigel G. and Salguero‐Gómez, Roberto and Vindenes, Yngvild",
    title = "Life history adaptations to fluctuating environments: Combined effects of demographic buffering and lability",
    year = "2022",
    journal = "Ecology Letters",
    abstract = "Demographic buffering and lability have been identified as adaptive strategies to optimise fitness in a fluctuating environment. These are not mutually exclusive, however, we lack efficient methods to measure their relative importance for a given life history. Here, we decompose the stochastic growth rate (fitness) into components arising from nonlinear responses and variance-covariance of demographic parameters to an environmental driver, which allows studying joint effects of buffering and lability. We apply this decomposition for 154 animal matrix population models under different scenarios to explore how these main fitness components vary across life histories. Faster-living species appear more responsive to environmental fluctuations, either positively or negatively. They have the highest potential for strong adaptive demographic lability, while demographic buffering is a main strategy in slow-living species. Our decomposition provides a comprehensive framework to study how organisms adapt to variability through buffering and lability, and to predict species responses to climate change.",
    url = "https://doi.org/10.1111/ele.14071",
    doi = "10.1111/ele.14071",
    openalex = "W4292550611",
    references = "doi101093oso97801988386090030009"
}

HIGHLIGHTS Subcoccinella vigintiquatuorpunctata is one of the main pest on alfalfa. Age-specific life table and survival rate for each life stage was calculated by using TWOSEX-MSChart. This study suggest the life table can be used for the biology and control of the alfalfa pest.

@article{doi101590167843242022210841,
    author = "Barış, Aydemir",
    title = "Age-Stage, Two-Sex Life Tables of the 24 Spot Ladybird [(Subcoccinella vigintiquatuorpunctata (Coleoptera: Coccinellidae)]",
    year = "2022",
    journal = "Brazilian Archives of Biology and Technology",
    abstract = "HIGHLIGHTS Subcoccinella vigintiquatuorpunctata is one of the main pest on alfalfa. Age-specific life table and survival rate for each life stage was calculated by using TWOSEX-MSChart. This study suggest the life table can be used for the biology and control of the alfalfa pest.",
    url = "https://doi.org/10.1590/1678-4324-2022210841",
    doi = "10.1590/1678-4324-2022210841",
    openalex = "W4295278701",
    references = "doi1016970ted74888"
}

Maturation schedules shape the age structure of a population and influence productivity and exposure to fishing. Fish cultivated and raised in artificial environments such as hatcheries may mature at different ages compared to their natural-origin counterparts. We evaluated whether endangered Sacramento River winter-run Chinook salmon Oncorhynchus tshawytscha produced in a conservation hatchery had different maturation schedules compared to natural-origin fish, and how any differences affected their exposure to, and impact from, the ocean salmon fishery. Using coded-wire tags collected from hatchery fish in the ocean and in-river fisheries and on the spawning grounds, and scales collected from natural-origin spawner carcasses, we reconstructed the life history of hatchery and natural-origin cohorts from 2002-2015 brood years. Hatchery fish had similar age-2 maturation rates but higher age-3 maturation rates compared to natural-origin fish, resulting in fewer age-4 individuals and an overall more truncated age structure. Because natural-origin winter-run Chinook salmon were more likely to remain at sea until age 4, they were exposed to fishing for an additional year and experienced greater reduction in escapement. Compared to natural-origin males, hatchery-origin males were much less likely to return at an older age, possibly because sexual selection that is occurring on the spawning grounds is not occurring to the same extent in the hatchery. Identifying how reproductive maturation differs across sources, sex, and life histories is critical to understanding how fisheries can disproportionately impact subsets of a population and affect its long-term population dynamics and sustainability.

@article{doi103354meps14446,
    author = "Chen, E. R. and Satterthwaite, William H. and Kormos, B. and Johnson, RC and Phillis, CC and Carlson, Stephanie M.",
    title = "Age structure of natural versus hatchery-origin endangered Chinook salmon and implications for fisheries management in California",
    year = "2023",
    journal = "Marine Ecology Progress Series",
    abstract = "Maturation schedules shape the age structure of a population and influence productivity and exposure to fishing. Fish cultivated and raised in artificial environments such as hatcheries may mature at different ages compared to their natural-origin counterparts. We evaluated whether endangered Sacramento River winter-run Chinook salmon Oncorhynchus tshawytscha produced in a conservation hatchery had different maturation schedules compared to natural-origin fish, and how any differences affected their exposure to, and impact from, the ocean salmon fishery. Using coded-wire tags collected from hatchery fish in the ocean and in-river fisheries and on the spawning grounds, and scales collected from natural-origin spawner carcasses, we reconstructed the life history of hatchery and natural-origin cohorts from 2002-2015 brood years. Hatchery fish had similar age-2 maturation rates but higher age-3 maturation rates compared to natural-origin fish, resulting in fewer age-4 individuals and an overall more truncated age structure. Because natural-origin winter-run Chinook salmon were more likely to remain at sea until age 4, they were exposed to fishing for an additional year and experienced greater reduction in escapement. Compared to natural-origin males, hatchery-origin males were much less likely to return at an older age, possibly because sexual selection that is occurring on the spawning grounds is not occurring to the same extent in the hatchery. Identifying how reproductive maturation differs across sources, sex, and life histories is critical to understanding how fisheries can disproportionately impact subsets of a population and affect its long-term population dynamics and sustainability.",
    url = "https://doi.org/10.3354/meps14446",
    doi = "10.3354/meps14446",
    openalex = "W4387384654",
    references = "doi101093oso97801988398730010001"
}

The European hedgehog is in decline, triggering a need to monitor population dynamics to optimise conservation initiatives directed at this species. By counting periosteal growth lines, we determined the age of 388 dead European hedgehogs collected through citizen science in Denmark. The overall mean age was 1.8 years (1.6 years for females and 2.1 years for males), ranging between 0 and 16 years. We constructed life tables showing life expectancies at 2.1 years for females and 2.6 years for males. We discovered that male hedgehogs were more likely to have died in traffic than females, but traffic-related deaths peaked in July for both sexes. A sex difference was detected for non-traffic deaths, as most males died in July, and most females died in September. We created empirical survivorship curves and hazard curves showing that the risk of death for male hedgehogs remains approximately constant with age. In contrast, the risk of death for females increases with age. Most of the collected road-killed individuals died in rural habitats. The degree of inbreeding did not influence longevity. These new insights are important for preparing conservation strategies for the European hedgehog.

@article{doi103390ani13040626,
    author = "Rasmussen, Sophie Lund and Berg, Thomas B. and Martens, Helle Juel and Jones, Owen R.",
    title = "Anyone Can Get Old—All You Have to Do Is Live Long Enough: Understanding Mortality and Life Expectancy in European Hedgehogs (Erinaceus europaeus)",
    year = "2023",
    journal = "Animals",
    abstract = "The European hedgehog is in decline, triggering a need to monitor population dynamics to optimise conservation initiatives directed at this species. By counting periosteal growth lines, we determined the age of 388 dead European hedgehogs collected through citizen science in Denmark. The overall mean age was 1.8 years (1.6 years for females and 2.1 years for males), ranging between 0 and 16 years. We constructed life tables showing life expectancies at 2.1 years for females and 2.6 years for males. We discovered that male hedgehogs were more likely to have died in traffic than females, but traffic-related deaths peaked in July for both sexes. A sex difference was detected for non-traffic deaths, as most males died in July, and most females died in September. We created empirical survivorship curves and hazard curves showing that the risk of death for male hedgehogs remains approximately constant with age. In contrast, the risk of death for females increases with age. Most of the collected road-killed individuals died in rural habitats. The degree of inbreeding did not influence longevity. These new insights are important for preparing conservation strategies for the European hedgehog.",
    url = "https://doi.org/10.3390/ani13040626",
    doi = "10.3390/ani13040626",
    openalex = "W4320497309",
    references = "doi101093oso97801988386090030008"
}