Interspecific

@article{crombie1947interspecific2,
    author = "Crombie, A. C",
    title = "Interspecific competition",
    year = "1947",
    journal = "Journal of Animal Ecology, v. 16, p. 44-73",
    note = "talkorigins\_source = {true}; raw\_reference = {Crombie, A. C., 1947, Interspecific competition: Journal of Animal Ecology, v. 16, p. 44-73.}"
}

1. Interspecific competition between populations of D. melanogaster and D. funebris was studied. 2. Both species coexisted in population bottles for almost two years. 3. The survival of both species does not constitute an exception to the mathematical theories of competition of Lotka and Volterra. 4. Analysis showed that most of the competition occurred between the larvae. 5. The survival of both species can be attributed to fluctuations in the environment which favored first one species and then the other. The fresh yeasted medium was more favorable to the development of D. melanogaster larvae. As the food aged and other microorganisms appeared, it was more suitable for the growth of D. funebris larvae.

@article{doi101086281665,
    author = "Merrell, David J.",
    title = "Interspecific Competition between Drosophila funebris and Drosophila melanogaster",
    year = "1951",
    journal = "The American Naturalist",
    abstract = "1. Interspecific competition between populations of D. melanogaster and D. funebris was studied. 2. Both species coexisted in population bottles for almost two years. 3. The survival of both species does not constitute an exception to the mathematical theories of competition of Lotka and Volterra. 4. Analysis showed that most of the competition occurred between the larvae. 5. The survival of both species can be attributed to fluctuations in the environment which favored first one species and then the other. The fresh yeasted medium was more favorable to the development of D. melanogaster larvae. As the food aged and other microorganisms appeared, it was more suitable for the growth of D. funebris larvae.",
    url = "https://doi.org/10.1086/281665",
    doi = "10.1086/281665",
    openalex = "W1971702599"
}

It is shown that there is a fundamental contradiction in the mathematical theory of interspecific competition of Lotka and Volterra.

@article{andrewartha1953the,
    author = "Andrewartha, HG and Birch, LC",
    title = "The Lotka-Volterra Theory of Interspecific competition.",
    year = "1953",
    journal = "Australian Journal of Zoology",
    abstract = "It is shown that there is a fundamental contradiction in the mathematical theory of interspecific competition of Lotka and Volterra.",
    url = "https://doi.org/10.1071/zo9530174",
    doi = "10.1071/zo9530174",
    number = "2",
    openalex = "W2047123775",
    pages = "174-177",
    volume = "1"
}

@article{andrewartha1953the1,
    author = "Andrewartha, H. G. and Birch, L. C",
    title = "The Lotka-Volterra theory of interspecific competition",
    year = "1953",
    journal = "Aust. Journal Zoology, v. 1, p. 174-177",
    note = "talkorigins\_source = {true}; raw\_reference = {Andrewartha, H. G., and Birch, L. C., 1953, The Lotka-Volterra theory of interspecific competition: Aust. Journal Zoology, v. 1, p. 174-177.}"
}

@article{crowell1962reduced,
    author = "Crowell, Kenneth L.",
    title = "Reduced Interspecific Competition among the Birds of Bermuda",
    year = "1962",
    journal = "Ecology",
    url = "https://doi.org/10.2307/1932042",
    doi = "10.2307/1932042",
    number = "1",
    openalex = "W2034637962",
    pages = "75-88",
    volume = "43",
    references = "doi101002jmor1050500106, doi101086282070, doi101086282106, doi10114912429992, doi101163036551653x00024, doi1023071931600, doi1023071932254, doi1023074510687"
}

@misc{crowell1962reduced3,
    author = "Crowell, K. L",
    title = "Reduced interspecific competition among the birds of Bermuda",
    year = "1962",
    howpublished = "Ecology, v. 43, p. 75-88",
    note = "talkorigins\_source = {true}; raw\_reference = {Crowell, K. L., 1962, Reduced interspecific competition among the birds of Bermuda: Ecology, v. 43, p. 75-88.}"
}

Populations of six species of amphibians were manipulated in field enclosures to study the biological tractability of current concepts of the organization of natural communities. Experimental communities with a known composition of mature eggs were introduced into screen enclosures in a pond to assay the importance of competition and predation to the ecology of amphibian larvae in temporary ponds. The competitive ability of each population was measured by its survivorship, mean length of its larval period, and mean weight at metamorphosis. Three simultaneous experiments (requiring 70 enclosures and 137 populations) were replicated in a randomized complete—block design for variance analysis. The assumptions of the classical Lotka—Volterra model of competition were tested by raising Ambystoma laterale, Ambystoma tremblayi, and Ambystoma maculatum in all combinations of three initial densities (0, 32, and 64). All three measures of competitive ability were affected by competition with other species. Higher—order interactions decreased the variance of the outcomes of the experiments as species were added to the communities. The statistical effects of these higher—order interactions between the densities of competing species often exceeded the simple effects of competition. The increase in community stability with the addition of species to the community is not predicted by the classical models of community ecology. The second experiment tested the effects of adjacent trophic levels on the structure of the three—species community. Eggs of Ambystoma tigrinum, a predator, and Rana sylvatica, an alternate prey of Ambystoma tigrinum, were added singly and together into systems with 16 eggs of species in the Maculatum species—group. Ambystoma tigrinum was a predator if it acquired an initial size advantage by preying on Rana sylvatica tadpoles; otherwise it was principally a competitor. Rana sylvatica adversely affected the Maculatum group by competing with invertebrate prey for periphyton and photoplankton. The three species in the Maculatum group had nearly the same response to the addition of both A. tigrinum and R. sylvatica. Ambystoma texanum, which occurs sporadically in southn Michigan at the northern limit of its range but not on the study area, was introduced as a test for community saturation. Ambystoma texanum was successfully raised alone. When mixed with the Maculatum group, Ambystoma texanum had a low survivorship, a small body size, and a long larval period. The native species were affected equally by the introduction of Ambystoma texanum, demonstrating the complexity of the food web and the ecological pliability of salamander larvae. The uncertainty of the temporary pond environment precludes extreme ecological specialization among these species of salamanders. Coexistence is a consequence of the relative advantages of the species in different years and the long adult life spans. The complexity of the food web and "predator switching" are probably important elements of the density dependent interactions that contribute to the stability of communities within seasons.

@article{doi1023071935707,
    author = "Wilbur, Henry M.",
    title = "Competition, Predation, and the Structure of the Ambystoma‐Rana Sylvatica Community",
    year = "1972",
    journal = "Ecology",
    abstract = {Populations of six species of amphibians were manipulated in field enclosures to study the biological tractability of current concepts of the organization of natural communities. Experimental communities with a known composition of mature eggs were introduced into screen enclosures in a pond to assay the importance of competition and predation to the ecology of amphibian larvae in temporary ponds. The competitive ability of each population was measured by its survivorship, mean length of its larval period, and mean weight at metamorphosis. Three simultaneous experiments (requiring 70 enclosures and 137 populations) were replicated in a randomized complete—block design for variance analysis. The assumptions of the classical Lotka—Volterra model of competition were tested by raising Ambystoma laterale, Ambystoma tremblayi, and Ambystoma maculatum in all combinations of three initial densities (0, 32, and 64). All three measures of competitive ability were affected by competition with other species. Higher—order interactions decreased the variance of the outcomes of the experiments as species were added to the communities. The statistical effects of these higher—order interactions between the densities of competing species often exceeded the simple effects of competition. The increase in community stability with the addition of species to the community is not predicted by the classical models of community ecology. The second experiment tested the effects of adjacent trophic levels on the structure of the three—species community. Eggs of Ambystoma tigrinum, a predator, and Rana sylvatica, an alternate prey of Ambystoma tigrinum, were added singly and together into systems with 16 eggs of species in the Maculatum species—group. Ambystoma tigrinum was a predator if it acquired an initial size advantage by preying on Rana sylvatica tadpoles; otherwise it was principally a competitor. Rana sylvatica adversely affected the Maculatum group by competing with invertebrate prey for periphyton and photoplankton. The three species in the Maculatum group had nearly the same response to the addition of both A. tigrinum and R. sylvatica. Ambystoma texanum, which occurs sporadically in southn Michigan at the northern limit of its range but not on the study area, was introduced as a test for community saturation. Ambystoma texanum was successfully raised alone. When mixed with the Maculatum group, Ambystoma texanum had a low survivorship, a small body size, and a long larval period. The native species were affected equally by the introduction of Ambystoma texanum, demonstrating the complexity of the food web and the ecological pliability of salamander larvae. The uncertainty of the temporary pond environment precludes extreme ecological specialization among these species of salamanders. Coexistence is a consequence of the relative advantages of the species in different years and the long adult life spans. The complexity of the food web and "predator switching" are probably important elements of the density dependent interactions that contribute to the stability of communities within seasons.},
    url = "https://doi.org/10.2307/1935707",
    doi = "10.2307/1935707",
    openalex = "W2010429517",
    references = "doi101086282146, doi101086282171, doi101086282400, doi101086282505, doi101126science150369228, doi10129879780300188479022, doi1015159781400881376, doi1023072257385, doi102307jctvx5wbbh, openalexw1500291103"
}

SUMMARYDow, D. D. 1977. Indiscriminate interspecific aggression leading to almost sole occupancy of space by a single species of bird. Emu 77: 115–121.Noisy Miners Manorina melanocephala, Australian honeyeaters, reside and feed in dense colonies in open woodland all year. All other species entering these colonies are attacked, sometimes killed. M. melanocephala, through group aggression, successfully defends its colonies against intrusion and settlement by other species of birds. Comparison with scarcer populations in more structurally complex woodland, where the species is less able to eliminate others, suggests that the advantage gained by the interspecific aggression pertains to food resources, because the species forages more in a wider range of feeding zones in areas where possible competitors have been ousted. By eliminating virtually all competitors, M. melanocephala gains exclusive use of all food resources in its colonies. Such interspecific interaction is unique among birds and possibly among animals in general. Also, M. melanocephala breeds communally, i.e. many individuals feed the young in a single nest. Food items given to the young are usually very small and the number of feeding trips to the nest extremely high. This high rate of feeding may be necessitated by the relatively greater abundance of small insects, which in turn could be due to the complete absence of smaller avian competitors.

@article{doi101071mu9770115,
    author = "Dow, Douglas",
    title = "Indiscriminate Interspecific Aggression Leading to Almost Sole Occupancy of Space by a Single Species of Bird",
    year = "1977",
    journal = "Emu - Austral Ornithology",
    abstract = "SUMMARYDow, D. D. 1977. Indiscriminate interspecific aggression leading to almost sole occupancy of space by a single species of bird. Emu 77: 115–121.Noisy Miners Manorina melanocephala, Australian honeyeaters, reside and feed in dense colonies in open woodland all year. All other species entering these colonies are attacked, sometimes killed. M. melanocephala, through group aggression, successfully defends its colonies against intrusion and settlement by other species of birds. Comparison with scarcer populations in more structurally complex woodland, where the species is less able to eliminate others, suggests that the advantage gained by the interspecific aggression pertains to food resources, because the species forages more in a wider range of feeding zones in areas where possible competitors have been ousted. By eliminating virtually all competitors, M. melanocephala gains exclusive use of all food resources in its colonies. Such interspecific interaction is unique among birds and possibly among animals in general. Also, M. melanocephala breeds communally, i.e. many individuals feed the young in a single nest. Food items given to the young are usually very small and the number of feeding trips to the nest extremely high. This high rate of feeding may be necessitated by the relatively greater abundance of small insects, which in turn could be due to the complete absence of smaller avian competitors.",
    url = "https://doi.org/10.1071/mu9770115",
    doi = "10.1071/mu9770115",
    openalex = "W2313592817",
    references = "doi1023071930"
}

Rare until recently, field-experimental studies of interspecific competition now number well over 150. Competition was found in 90% of the studies and 76% of their species, indicating its pervasive importance in ecological systems. Exploitative competition and interference competition were apparent mechanisms about equally often. Few experiments showed year-to-year variation in the existence of competition, though more did in its intensity; many were not long-term. The Hairston-Slobodkin-Smith hypothesis concerning variation in the importance of competition between trophic levels was strongly supported for terrestrial and freshwater systems. In particular, producers, and granivores, nectarivores, carnivores, and scavengers taken together, showed more competition than did phytophagous herbivores and filter feeders. In marine systems, virtually no trend was detectable one way or the other. Large heterotrophs competed more than small ones in most comparisons, and other properties possibly deterring predation, such as stinging behavior, seemed also characteristic of species competing frequently. Among terrestrial plants and certain terrestrial animals but not all, experiments carried out in enclosures were more likely to show competition than unenclosed experiments. A greater ecological overlap implied a greater tendency to compete, as determined experimentally, when niche dimensions were food type or microhabitat; the opposite was true for macrohabitat. A substantial number of studies showed asymmetry in their species' response to competition; larger species were significantly more often superior than smaller ones, though a variety of other apparent reasons for asymmetry also existed. The integration of competition theory into field experimentation has only just begun.

@article{doi101086284133,
    author = "Schoener, Thomas W.",
    title = "Field Experiments on Interspecific Competition",
    year = "1983",
    journal = "The American Naturalist",
    abstract = "Rare until recently, field-experimental studies of interspecific competition now number well over 150. Competition was found in 90\% of the studies and 76\% of their species, indicating its pervasive importance in ecological systems. Exploitative competition and interference competition were apparent mechanisms about equally often. Few experiments showed year-to-year variation in the existence of competition, though more did in its intensity; many were not long-term. The Hairston-Slobodkin-Smith hypothesis concerning variation in the importance of competition between trophic levels was strongly supported for terrestrial and freshwater systems. In particular, producers, and granivores, nectarivores, carnivores, and scavengers taken together, showed more competition than did phytophagous herbivores and filter feeders. In marine systems, virtually no trend was detectable one way or the other. Large heterotrophs competed more than small ones in most comparisons, and other properties possibly deterring predation, such as stinging behavior, seemed also characteristic of species competing frequently. Among terrestrial plants and certain terrestrial animals but not all, experiments carried out in enclosures were more likely to show competition than unenclosed experiments. A greater ecological overlap implied a greater tendency to compete, as determined experimentally, when niche dimensions were food type or microhabitat; the opposite was true for macrohabitat. A substantial number of studies showed asymmetry in their species' response to competition; larger species were significantly more often superior than smaller ones, though a variety of other apparent reasons for asymmetry also existed. The integration of competition theory into field experimentation has only just begun.",
    url = "https://doi.org/10.1086/284133",
    doi = "10.1086/284133",
    openalex = "W2064242117",
    references = "dayton1971competition, doi101016s0065250408603190, doi101038260204c0, doi101086282070, doi101086282146, doi101086282400, doi101086282415, doi101086282477, doi101086282478, doi101086282505, doi1023071933500, doi1023071935707, doi1023071942484, doi1023073280305, doi105962bhltitle4489, openalexw2077454220"
}

In a strictly defined sample of competition studies using controlled field experiments, covering 215 species and 527 experiments, competition was found in most of the studies, in somewhat more than half of the species, and in about two-fifths of the experiments. In most of these experiments interspecific competition was not distinguished from intraspecific competition. In the few studies in which the two were separated, interspecific competition was the stronger form in about onesixth of all experiments done. When competition was demonstrated, intraspecific competition was as strong or stronger than interspecific in three-quarters of the experiments. Some evidence from this literature survey suggests that negative results may be underrepresented, so that the absolute values of these figures may be too high. Since this bias should apply also to studies of all taxa, habitats, or other interactions it should not greatly affect estimates of the relative prevalence of competition. Since these estimates come from field experiments open to other influences such as predators, grazers, weather, disturbances, etc., they should provide a fair approximation of the relative prevalence of interspecific and intraspecific competition in natural ecological communities. The prevalence of competition in these studies varied. Marine organisms showed consistently higher frequencies of competition than terrestrial ones as did large-sized organisms as compared to smaller ones. Plants, herbivores, and carnivores showed similar frequencies of competition in all habitats compared. The incidence of competition varied considerably from year to year and place to place. In some categories, evidence concerning competition is sparse. More studies are needed of all freshwater species, marine vertebrates, parasites, effects on resource partitioning, and particularly the relative strengths of interspecific versus intraspecific competition. When both members of a pair were studied and some competition found, only one member was affected in well over half the experiments. Such strong asymmetrical competition is not always consistent in direction; reversals in the rank order of competitive superiority have been demonstrated by field experiments and direct observations. Some positive interactions were found. These may have been a consequence of actual positive influences or of negative ones acting indirectly through other species. The latter may also apply to some of the negative interactions interpreted as competition in these studies. If only the input and output of an experiment are known, it is difficult to decide what mechanism produced the observed effect. While many of the experiments probably have been correctly interpreted, the present survey illustrates how difficult it is to produce a clear and unambiguous demonstration of interspecific competition.

@article{doi101086284165,
    author = "Connell, Joseph H.",
    title = "On the Prevalence and Relative Importance of Interspecific Competition: Evidence from Field Experiments",
    year = "1983",
    journal = "The American Naturalist",
    abstract = "In a strictly defined sample of competition studies using controlled field experiments, covering 215 species and 527 experiments, competition was found in most of the studies, in somewhat more than half of the species, and in about two-fifths of the experiments. In most of these experiments interspecific competition was not distinguished from intraspecific competition. In the few studies in which the two were separated, interspecific competition was the stronger form in about onesixth of all experiments done. When competition was demonstrated, intraspecific competition was as strong or stronger than interspecific in three-quarters of the experiments. Some evidence from this literature survey suggests that negative results may be underrepresented, so that the absolute values of these figures may be too high. Since this bias should apply also to studies of all taxa, habitats, or other interactions it should not greatly affect estimates of the relative prevalence of competition. Since these estimates come from field experiments open to other influences such as predators, grazers, weather, disturbances, etc., they should provide a fair approximation of the relative prevalence of interspecific and intraspecific competition in natural ecological communities. The prevalence of competition in these studies varied. Marine organisms showed consistently higher frequencies of competition than terrestrial ones as did large-sized organisms as compared to smaller ones. Plants, herbivores, and carnivores showed similar frequencies of competition in all habitats compared. The incidence of competition varied considerably from year to year and place to place. In some categories, evidence concerning competition is sparse. More studies are needed of all freshwater species, marine vertebrates, parasites, effects on resource partitioning, and particularly the relative strengths of interspecific versus intraspecific competition. When both members of a pair were studied and some competition found, only one member was affected in well over half the experiments. Such strong asymmetrical competition is not always consistent in direction; reversals in the rank order of competitive superiority have been demonstrated by field experiments and direct observations. Some positive interactions were found. These may have been a consequence of actual positive influences or of negative ones acting indirectly through other species. The latter may also apply to some of the negative interactions interpreted as competition in these studies. If only the input and output of an experiment are known, it is difficult to decide what mechanism produced the observed effect. While many of the experiments probably have been correctly interpreted, the present survey illustrates how difficult it is to produce a clear and unambiguous demonstration of interspecific competition.",
    url = "https://doi.org/10.1086/284165",
    doi = "10.1086/284165",
    openalex = "W1998245410",
    references = "doi101016b9780127114422x50016, doi101086282146, doi101086282478, doi101086283073, doi101086284133, doi101111j109583121972tb00690x, doi101126science185414527, doi1023071933500, doi1023071935707, doi1023071942404, doi1023071942484, doi1023071942563, openalexw2077454220"
}

@article{cushing1986periodic,
    author = "Cushing, J. M.",
    title = "Periodic Lotka-Volterra competition equations",
    year = "1986",
    journal = "Journal of Mathematical Biology",
    url = "https://doi.org/10.1007/bf01236888",
    doi = "10.1007/bf01236888",
    number = "4",
    openalex = "W2045132513",
    pages = "381-403",
    volume = "24",
    references = "doi1010079783642665264, doi101007bf00276097, doi1010160016003256911504, doi10106313059875, doi101086282171, doi1015159780691187051017, doi1015159780691206912, doi1023071376351, doi1023071934593, openalexw2022778243"
}

@article{guowei1991a,
    author = "Guowei, Sun and Qiwu, Cui and Bo, Song",
    title = "A new mathematical model of interspecific competition — an expansion of the classical Lotka-Volterra competition equations",
    year = "1991",
    journal = "Ecological Modelling",
    url = "https://doi.org/10.1016/0304-3800(91)90040-8",
    doi = "10.1016/0304-3800(91)90040-8",
    number = "1-4",
    openalex = "W2013258763",
    pages = "273-284",
    volume = "58",
    references = "doi101038116461b0, doi101038118558a0, doi101038119012b0, doi101086283633, doi101111j155856461970tb01782x, doi101146annureves13110182002025, doi1023072406825, doi1023072965538, doi105962bhltitle4489, openalexw2971318137"
}

@article{neuhauser1999an,
    author = "Neuhauser, Claudia and Pacala, Stephen W.",
    title = "An explicitly spatial version of the Lotka-Volterra model with interspecific competition",
    year = "1999",
    journal = "The Annals of Applied Probability",
    url = "https://doi.org/10.1214/aoap/1029962871",
    doi = "10.1214/aoap/1029962871",
    number = "4",
    openalex = "W2094928855",
    volume = "9",
    references = "doi101006tpbi19941032, doi1010079781461385424, doi1010160001870870900344, doi101093biomet603581, doi101093icesjms313, doi101201978131537314016, doi101214aop1176996306, doi1023072963479, doi1023074549, openalexw1989371375"
}

Summary In this journal 35 years ago, P. H. Leslie, T. Park and D. B. Mertz reported competitive exclusion data for two Tribolium species. It is less well‐known that they also reported ‘difficult to interpret’ coexistence data. We suggest that the species exclusion and the species coexistence are consequences of a stable coexistence two‐cycle in the presence of two stable competitive exclusion equilibria. A stage‐structured insect population model for two interacting species forecasts that as interspecific interaction is increased there occurs a sequence of dynamic changes (bifurcations) in which the classic Lotka–Volterra‐type scenario with two stable competitive exclusion equilibria is altered abruptly to a novel scenario with three locally stable entities; namely, two competitive exclusion equilibria and a stable coexistence cycle. This scenario is novel in that it predicts the competitive coexistence of two nearly identical species on a single limiting resource and does so under circumstances of increased interspecific competition. This prediction is in contradiction to classical tenets of competition theory.

@article{doi101046j13652656200300743x,
    author = "Edmunds, Jeffrey and Cushing, J. M. and Costantino, R. F. and Henson, Shandelle M. and Dennis, Brian and Desharnais, Robert A.",
    title = "Park's Tribolium competition experiments: a non‐equilibrium species coexistence hypothesis",
    year = "2003",
    journal = "Journal of Animal Ecology",
    abstract = "Summary In this journal 35 years ago, P. H. Leslie, T. Park and D. B. Mertz reported competitive exclusion data for two Tribolium species. It is less well‐known that they also reported ‘difficult to interpret’ coexistence data. We suggest that the species exclusion and the species coexistence are consequences of a stable coexistence two‐cycle in the presence of two stable competitive exclusion equilibria. A stage‐structured insect population model for two interacting species forecasts that as interspecific interaction is increased there occurs a sequence of dynamic changes (bifurcations) in which the classic Lotka–Volterra‐type scenario with two stable competitive exclusion equilibria is altered abruptly to a novel scenario with three locally stable entities; namely, two competitive exclusion equilibria and a stable coexistence cycle. This scenario is novel in that it predicts the competitive coexistence of two nearly identical species on a single limiting resource and does so under circumstances of increased interspecific competition. This prediction is in contradiction to classical tenets of competition theory.",
    url = "https://doi.org/10.1046/j.1365-2656.2003.00743.x",
    doi = "10.1046/j.1365-2656.2003.00743.x",
    openalex = "W2116410587",
    references = "cushing1986periodic"
}

The role of interspecific competition as a key factor in the ecology of natural communities where species exploit limited resources is well established, and the study of competition dynamics in snake communities has received much attention in recent years. Twenty years ago, an acclaimed review () suggested that snakes were atypical among vertebrates because sympatric species usually partition the food niche. Here, I review the articles published in the last two decades with the aim of finding any general geographical or guild patterns and assessing if Toft's main conclusion is still supported by new evidence. Where appropriate, I use Monte Carlo simulations to establish whether observed patterns of niche overlap are real, or if they have occurred by chance. My study shows clear congruence in the patterns of coexistence exhibited by snake communities in different regions of the world, i.e.: (1) cold regions of the northern hemisphere (high latitudes and altitudes) exhibit low species richness and a very low, or even absent, potential for interspecific competition; (2) aquatic snakes that form communities in temperate regions generally partition the food type available and exhibit a broad similarity in habitat use with subtle differences in microhabitat use; (3) terrestrial snake communities in temperate regions are very variable in terms of their coexistence dynamics and show no evidence of generalised patterns; (4) sympatric viperids in Europe, North America and, most interestingly, tropical Asia partition the available habitat but not the prey resource; (5) competition is much stronger in tropical snake communities, and the intensity of this process fluctuates throughout the year being most intense during periods of low food availability; (6) in general, tropical snakes partition the food resource (prey type and/or prey size), but when this resource is not partitioned competitive exclusion can occur. Prey resource availability is a fundamental variable for all snake communities; this is clearly documented by studies on terrestrial snakes in Australia where, due to a relative scarcity of prey availability in the field, sympatry among species is much rarer than in other continents. I conclude that, although there are several notable exceptions, Toft's main conclusion is still supported by empirical evidence. However, I disagree with Toft's conclusion that most snakes are food specialists, and I contend that interspecific competition is important in structuring many (if not most) of the snake communities around the world.

@article{doi101111j20060030129914064x,
    author = "Luiselli, Luca",
    title = "Resource partitioning and interspecific competition in snakes: the search for general geographical and guild patterns",
    year = "2006",
    journal = "Oikos",
    abstract = "The role of interspecific competition as a key factor in the ecology of natural communities where species exploit limited resources is well established, and the study of competition dynamics in snake communities has received much attention in recent years. Twenty years ago, an acclaimed review () suggested that snakes were atypical among vertebrates because sympatric species usually partition the food niche. Here, I review the articles published in the last two decades with the aim of finding any general geographical or guild patterns and assessing if Toft's main conclusion is still supported by new evidence. Where appropriate, I use Monte Carlo simulations to establish whether observed patterns of niche overlap are real, or if they have occurred by chance. My study shows clear congruence in the patterns of coexistence exhibited by snake communities in different regions of the world, i.e.: (1) cold regions of the northern hemisphere (high latitudes and altitudes) exhibit low species richness and a very low, or even absent, potential for interspecific competition; (2) aquatic snakes that form communities in temperate regions generally partition the food type available and exhibit a broad similarity in habitat use with subtle differences in microhabitat use; (3) terrestrial snake communities in temperate regions are very variable in terms of their coexistence dynamics and show no evidence of generalised patterns; (4) sympatric viperids in Europe, North America and, most interestingly, tropical Asia partition the available habitat but not the prey resource; (5) competition is much stronger in tropical snake communities, and the intensity of this process fluctuates throughout the year being most intense during periods of low food availability; (6) in general, tropical snakes partition the food resource (prey type and/or prey size), but when this resource is not partitioned competitive exclusion can occur. Prey resource availability is a fundamental variable for all snake communities; this is clearly documented by studies on terrestrial snakes in Australia where, due to a relative scarcity of prey availability in the field, sympatry among species is much rarer than in other continents. I conclude that, although there are several notable exceptions, Toft's main conclusion is still supported by empirical evidence. However, I disagree with Toft's conclusion that most snakes are food specialists, and I contend that interspecific competition is important in structuring many (if not most) of the snake communities around the world.",
    url = "https://doi.org/10.1111/j.2006.0030-1299.14064.x",
    doi = "10.1111/j.2006.0030-1299.14064.x",
    openalex = "W2172048833",
    references = "doi1023071444785"
}

The importance of interspecific competition is a highly controversial and unresolved issue for community ecology in general, and for phytophagous insects in particular. Recent advancements, however, in our understanding of indirect (plant- and enemy-mediated) interactions challenge the historical paradigms of competition. Thus, in the context of this rapidly developing field, we re-evaluate the evidence for interspecific competition in phytophagous insects using a meta-analysis of published studies. Our analysis is specifically designed to test the assumptions underlying traditional competition theory, namely that competitive interactions are symmetrical, necessitate spatial and temporal co-occurrence, and increase in intensity as the density, phylogenetic similarity, and niche overlap of competing species increase. Despite finding frequent evidence for competition, we found very little evidence that plant-feeding insects conform to theoretical predictions for interspecific competition. Interactions were highly asymmetrical, similar in magnitude within vs. between feeding guilds (chewers vs. sap-feeders), and were unaffected by the quantity of resources removed (% defoliation). There was mixed support for the effects of phylogeny, spatial/temporal separation, and the relative strength of intra- vs. interspecific competition. Clearly, a new paradigm that accounts for indirect interactions and facilitation is required to describe how interspecific competition contributes to the organization of phytophagous insect communities, and perhaps to other plant and animal communities as well.

@article{doi101111j14610248200701093x,
    author = "Kaplan, Ian and Denno, Robert F.",
    title = "Interspecific interactions in phytophagous insects revisited: a quantitative assessment of competition theory",
    year = "2007",
    journal = "Ecology Letters",
    abstract = "The importance of interspecific competition is a highly controversial and unresolved issue for community ecology in general, and for phytophagous insects in particular. Recent advancements, however, in our understanding of indirect (plant- and enemy-mediated) interactions challenge the historical paradigms of competition. Thus, in the context of this rapidly developing field, we re-evaluate the evidence for interspecific competition in phytophagous insects using a meta-analysis of published studies. Our analysis is specifically designed to test the assumptions underlying traditional competition theory, namely that competitive interactions are symmetrical, necessitate spatial and temporal co-occurrence, and increase in intensity as the density, phylogenetic similarity, and niche overlap of competing species increase. Despite finding frequent evidence for competition, we found very little evidence that plant-feeding insects conform to theoretical predictions for interspecific competition. Interactions were highly asymmetrical, similar in magnitude within vs. between feeding guilds (chewers vs. sap-feeders), and were unaffected by the quantity of resources removed (\% defoliation). There was mixed support for the effects of phylogeny, spatial/temporal separation, and the relative strength of intra- vs. interspecific competition. Clearly, a new paradigm that accounts for indirect interactions and facilitation is required to describe how interspecific competition contributes to the organization of phytophagous insect communities, and perhaps to other plant and animal communities as well.",
    url = "https://doi.org/10.1111/j.1461-0248.2007.01093.x",
    doi = "10.1111/j.1461-0248.2007.01093.x",
    openalex = "W2137980122",
    references = "doi101038118558a0, doi101038119012b0, doi101111j13652427200601592x, doi101146annureven40010195001501"
}

In this paper, we revisit the famous periodic Lotka–Volterra competitive system. Some new and interesting sufficient conditions are obtained to guarantee the existence and global asymptotic stability of the periodic solution in the Lotka–Volterra competitive system. Our method is based on Mawhin's coincidence degree, matrix's spectral theory, and some new estimation techniques for the priori bounds of unknown solutions to the equation $Lx=\lambda Nx$. Due to this new method, our new results are much different from the known results in the previous literature. Finally, some examples and their simulations show the feasibility of our results.

@article{doi101137070702485,
    author = "Xia, Yonghui and Han, Maoan",
    title = "New Conditions on the Existence and Stability of Periodic Solution in Lotka–Volterra's Population System",
    year = "2009",
    journal = "SIAM Journal on Applied Mathematics",
    abstract = "In this paper, we revisit the famous periodic Lotka–Volterra competitive system. Some new and interesting sufficient conditions are obtained to guarantee the existence and global asymptotic stability of the periodic solution in the Lotka–Volterra competitive system. Our method is based on Mawhin's coincidence degree, matrix's spectral theory, and some new estimation techniques for the priori bounds of unknown solutions to the equation $Lx=\lambda Nx$. Due to this new method, our new results are much different from the known results in the previous literature. Finally, some examples and their simulations show the feasibility of our results.",
    url = "https://doi.org/10.1137/070702485",
    doi = "10.1137/070702485",
    openalex = "W1984115968",
    references = "cushing1986periodic"
}

@incollection{stevens2009lotkavolterra,
    author = "Stevens, M. Henry H.",
    title = "Lotka–Volterra Interspecific Competition",
    year = "2009",
    booktitle = "Use R!",
    url = "https://doi.org/10.1007/978-0-387-89882-7\_5",
    doi = "10.1007/978-0-387-89882-7\_5",
    openalex = "W16518501",
    pages = "135-159"
}

@incollection{braude2010lotkavolterra,
    author = "Braude, Stanton and Scherer, Tara and McGaha, Rebecca",
    title = "Lotka–Volterra Competition Modeling",
    year = "2010",
    booktitle = "An Introduction to Methods and Models in Ecology, Evolution, and Conservation Biology",
    url = "https://doi.org/10.2307/j.ctvcm4gbm.14",
    doi = "10.2307/j.ctvcm4gbm.14",
    openalex = "W4256084897",
    pages = "69-78"
}

@incollection{crossref20107,
    title = "7. Lotka-Volterra Competition Modeling",
    year = "2010",
    booktitle = "An Introduction to Methods and Models in Ecology, Evolution, and Conservation Biology",
    url = "https://doi.org/10.1515/9781400835454-012",
    doi = "10.1515/9781400835454-012",
    openalex = "W2917020845",
    pages = "69-78",
    references = "doi101038119012b0, doi1023072965538"
}

Theory predicts that intraspecific competition should be stronger than interspecific competition for any pair of stably coexisting species, yet previous literature reviews found little support for this pattern. We screened over 5400 publications and identified 39 studies that quantified phenomenological intraspecific and interspecific interactions in terrestrial plant communities. Of the 67% of species pairs in which both intra- and interspecific effects were negative (competitive), intraspecific competition was, on average, four to five-fold stronger than interspecific competition. Of the remaining pairs, 93% featured intraspecific competition and interspecific facilitation, a situation that stabilises coexistence. The difference between intra- and interspecific effects tended to be larger in observational than experimental data sets, in field than greenhouse studies, and in studies that quantified population growth over the full life cycle rather than single fitness components. Our results imply that processes promoting stable coexistence at local scales are common and consequential across terrestrial plant communities.

@article{doi101111ele13098,
    author = "Adler, Peter B. and Smull, Danielle M and Beard, Karen H. and Choi, Ryan T. and Furniss, Tucker J. and Kulmatiski, Andrew and Meiners, Joan M. and Tredennick, Andrew T. and Veblen, Kari E.",
    title = "Competition and coexistence in plant communities: intraspecific competition is stronger than interspecific competition",
    year = "2018",
    journal = "Ecology Letters",
    abstract = "Theory predicts that intraspecific competition should be stronger than interspecific competition for any pair of stably coexisting species, yet previous literature reviews found little support for this pattern. We screened over 5400 publications and identified 39 studies that quantified phenomenological intraspecific and interspecific interactions in terrestrial plant communities. Of the 67\% of species pairs in which both intra- and interspecific effects were negative (competitive), intraspecific competition was, on average, four to five-fold stronger than interspecific competition. Of the remaining pairs, 93\% featured intraspecific competition and interspecific facilitation, a situation that stabilises coexistence. The difference between intra- and interspecific effects tended to be larger in observational than experimental data sets, in field than greenhouse studies, and in studies that quantified population growth over the full life cycle rather than single fitness components. Our results imply that processes promoting stable coexistence at local scales are common and consequential across terrestrial plant communities.",
    url = "https://doi.org/10.1111/ele.13098",
    doi = "10.1111/ele.13098",
    openalex = "W2811105108",
    references = "doi101038118558a0, doi101038nature22898"
}

The excessive proliferation of filamentous green algae (FGA) has been considered to be one of the important factors that result in poor growth or even a decline in submerged macrophytes. This study aims to investigate why FGA has stronger growth advantage than that of submerged macrophytes in the co-culture system. Assimilation of nitrogen and phosphorus nutrients, kinetics, and interspecific nutrient competition model were studied to determine the dynamic changes in nutrient assimilation between submerged macrophytes and FGA in a co-culture system with ion depletion technique. The results showed that differences were observed in the assimilation of nitrogen and phosphorus by Vallisneria natans, Ceratophyllum demersum, and Cladophora oligoclona. C. oligoclona was able to assimilate and accumulate much more nitrogen than V. natans and C. demersum, with the content of nitrogen of 5.75% (dry mass). The lower value of Michaelis-Menten constant K m (0.34 mg/L) of C. demersum indicated that C. demersum had a greater affinity for phosphate. The interspecific competition results confirmed that the coexistence of V. natans and C. oligoclona, and C. demersum and C. oligoclona were unstable. Moreover, C. demersum had a stronger competitive ability than V. natans, and it can be used as a pioneer species for the recovery of submerged vegetation in eutrophic lakes.

@article{doi1015244pjoes87097,
    author = "Zhang, Lu and Liu, Biyun and Ge, Fangjie and Liu, Qi and Zhang, Yongyuan and Zhou, Qiaohong and Xu, Dong and Wu, Zhenbin",
    title = "Interspecific Competition for Nutrients betweenSubmerged Macrophytes (Vallisneria natans,Ceratophyllum demersum) and Filamentous GreenAlgae (Cladophora oligoclona)in a Co-Culture System",
    year = "2018",
    journal = "Polish Journal of Environmental Studies",
    abstract = "The excessive proliferation of filamentous green algae (FGA) has been considered to be one of the important factors that result in poor growth or even a decline in submerged macrophytes. This study aims to investigate why FGA has stronger growth advantage than that of submerged macrophytes in the co-culture system. Assimilation of nitrogen and phosphorus nutrients, kinetics, and interspecific nutrient competition model were studied to determine the dynamic changes in nutrient assimilation between submerged macrophytes and FGA in a co-culture system with ion depletion technique. The results showed that differences were observed in the assimilation of nitrogen and phosphorus by Vallisneria natans, Ceratophyllum demersum, and Cladophora oligoclona. C. oligoclona was able to assimilate and accumulate much more nitrogen than V. natans and C. demersum, with the content of nitrogen of 5.75\% (dry mass). The lower value of Michaelis-Menten constant K m (0.34 mg/L) of C. demersum indicated that C. demersum had a greater affinity for phosphate. The interspecific competition results confirmed that the coexistence of V. natans and C. oligoclona, and C. demersum and C. oligoclona were unstable. Moreover, C. demersum had a stronger competitive ability than V. natans, and it can be used as a pioneer species for the recovery of submerged vegetation in eutrophic lakes.",
    url = "https://doi.org/10.15244/pjoes/87097",
    doi = "10.15244/pjoes/87097",
    openalex = "W2900305854",
    references = "guowei1991a"
}

The contribution of interspecific competition to structuring population and community dynamics remains controversial and poorly tested. Interspecific competition has long been thought to influence the structure of migrant-resident bird communities in winter, yet experimental evidence remains elusive. The arrival of billions of songbirds into Neotropical habitats, where they co-exist with residents, provides a unique opportunity to assess interspecific competition and its consequences. Working in 15 ha of Jamaican black mangrove forest, we used removal experiments to test whether dominant resident Yellow Warblers compete interspecifically with subordinate wintering American Redstarts; we also used observational evidence (interspecific territorial overlap) to understand whether this coexistence influences physical condition, spring departure dates or annual return rates. Consistent with interspecific competition, after experimental removal of the resident, yearling male Redstarts (but not females or adult males) immediately moved into vacated Yellow Warbler territories, increasing their overlap with the space by 7.3%. Yearling Redstarts also appeared to adjust their territorial space use by actively avoiding Yellow Warblers; for example, Redstarts departing the wintering grounds as yearlings and returning the following winter shifted such that their territories overlapped 32% less with those of Yellow Warblers. Adult Redstarts showed no such territorial flexibility. Adult male Redstarts also showed evidence supporting the consequences of coexistence: territorial overlap with Yellow Warblers was negatively correlated with body condition and annual return rates. Adult male Redstarts with <25% territorial overlap with Yellow Warblers were more than three times as likely to return between seasons than those with 100% overlap. We propose that the territorial inflexibility of adult male Redstarts produces these consequences, which may be due to their years-long investment in that particular territory. More generally, the temporary nature of migrant-resident interspecific competition is likely what allows coexistence during winter, the most resource-poor time of year. Interspecific competition and the consequences of coexistence are likely age- and sex-specific and the product of intraspecific dominance hierarchy in Redstarts. Our observations suggest that interspecific coexistence has measurable consequences, and our experiments support the long-held, but previously untested belief that resident birds compete interspecifically with wintering migrants.

@article{doi101002ecy3208,
    author = "Powell, Luke L. and Ames, Elizabeth M and Wright, James R. and Matthiopoulos, Jason and Marra, Peter P.",
    title = "Interspecific competition between resident and wintering birds: experimental evidence and consequences of coexistence",
    year = "2020",
    journal = "Ecology",
    abstract = "The contribution of interspecific competition to structuring population and community dynamics remains controversial and poorly tested. Interspecific competition has long been thought to influence the structure of migrant-resident bird communities in winter, yet experimental evidence remains elusive. The arrival of billions of songbirds into Neotropical habitats, where they co-exist with residents, provides a unique opportunity to assess interspecific competition and its consequences. Working in 15 ha of Jamaican black mangrove forest, we used removal experiments to test whether dominant resident Yellow Warblers compete interspecifically with subordinate wintering American Redstarts; we also used observational evidence (interspecific territorial overlap) to understand whether this coexistence influences physical condition, spring departure dates or annual return rates. Consistent with interspecific competition, after experimental removal of the resident, yearling male Redstarts (but not females or adult males) immediately moved into vacated Yellow Warbler territories, increasing their overlap with the space by 7.3\%. Yearling Redstarts also appeared to adjust their territorial space use by actively avoiding Yellow Warblers; for example, Redstarts departing the wintering grounds as yearlings and returning the following winter shifted such that their territories overlapped 32\% less with those of Yellow Warblers. Adult Redstarts showed no such territorial flexibility. Adult male Redstarts also showed evidence supporting the consequences of coexistence: territorial overlap with Yellow Warblers was negatively correlated with body condition and annual return rates. Adult male Redstarts with <25\% territorial overlap with Yellow Warblers were more than three times as likely to return between seasons than those with 100\% overlap. We propose that the territorial inflexibility of adult male Redstarts produces these consequences, which may be due to their years-long investment in that particular territory. More generally, the temporary nature of migrant-resident interspecific competition is likely what allows coexistence during winter, the most resource-poor time of year. Interspecific competition and the consequences of coexistence are likely age- and sex-specific and the product of intraspecific dominance hierarchy in Redstarts. Our observations suggest that interspecific coexistence has measurable consequences, and our experiments support the long-held, but previously untested belief that resident birds compete interspecifically with wintering migrants.",
    url = "https://doi.org/10.1002/ecy.3208",
    doi = "10.1002/ecy.3208",
    openalex = "W3089006945",
    references = "doi1023071930"
}