Journal articles: 'Models for competing specie'

7

Lopez-Gomez, Julian, and Jose C. Sabina De Lis. "Coexistence States and Global Attractivity for Some Convective Diffusive Competing Species Models." Transactions of the American Mathematical Society 347, no. 10 (1995): 3797. http://dx.doi.org/10.2307/2155205.

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López-Gómez, Julián, and José C. Sabina de Lis. "Coexistence states and global attractivity for some convective diffusive competing species models." Transactions of the American Mathematical Society 347, no. 10 (1995): 3797–833. http://dx.doi.org/10.1090/s0002-9947-1995-1311910-8.

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9

Sumner, Suzanne. "STABLE PERIODIC BEHAVIOR IN PIONEER-CLIMAX COMPETING SPECIES MODELS WITH CONSTANT RATE FORCING." Natural Resource Modeling 11, no. 2 (1998): 155–71. http://dx.doi.org/10.1111/j.1939-7445.1998.tb00306.x.

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10

Dancer, E. N. "On the existence and uniqueness of positive solutions for competing species models with diffusion." Transactions of the American Mathematical Society 326, no. 2 (1991): 829–59. http://dx.doi.org/10.1090/s0002-9947-1991-1028757-9.

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11

López-López, Pascual, Alvaro Soutullo, Clara García-Ripollés, Vicente Urios, Luis Cadahía, and Miguel Ferrer. "Markov models of territory occupancy: implications for the management and conservation of competing species." Biodiversity and Conservation 18, no. 5 (2008): 1389–402. http://dx.doi.org/10.1007/s10531-008-9469-2.

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12

Chamoun, Georges. "Finite Volume Analysis of the Two Competing-species Chemotaxis Models with General Diffusive Functions." WSEAS TRANSACTIONS ON BIOLOGY AND BIOMEDICINE 22 (April 14, 2025): 232–47. https://doi.org/10.37394/23208.2025.22.24.

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This paper aims to see how different spatial and environmental factors affect the coexistence or the exclusion of two species, while chemotaxis draws them towards a higher concentration of nutrients. For that, we analyze a robust numerical scheme applied for competitive two-species chemotaxis models with heterogeneous and potentially discontinuous diffusive coefficients. This extension is essential because diffusion can lead to discontinuities when the conductivities of the medium’s components differ. In this work, we examine a generalized finite volume scheme on admissible meshes, where the line joining the circumcenters of two neighboring volumes is orthogonal to their common interface, and the discontinuities coincide with the mesh interfaces. Finite volume methods are well-suited for problems involving conservation laws and can naturally handle discontinuities, making them an ideal candidate. To achieve the convergence, we first derive the discrete problem and then we show that the discrete solution converges to a weak solution of the continuous model. Finally, many simulations were performed using Fortran software, with the introduction of a reliable computational algorithm. The efficiency of our numerical approach for finding the discrete solutions is then carefully evaluated with many test cases focusing on the heterogeneity and the discontinuity of the diffusive coefficients.

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James Omaiye, Ojonubah. "Numerical Analysis of Ordinary Differential Equations of Ecological Competing Species Across Diverse Environments." African Journal of Mathematics and Statistics Studies 6, no. 1 (2023): 88–102. http://dx.doi.org/10.52589/ajmss_evssxtr7.

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In a geographical region, species have their range margins (i.e., the geographic boundaries where species can be found). Several species distribution models have shown that environmental factors (i.e., abiotic factors) and species interactions (i.e., biotic interactions) are responsible for shaping the distributions of species. Yet, most of the models often focus on one of these factors and ignore their joint effects. Consequently, predicting which species will exist and at what range margins is a challenge in ecology. Thus, in this paper, the combined influences of these ecological factors on multi-species community structures are studied. An ordinary differential equations (ODE) model is employed to study multi-species competition interactions across diverse environments. The model is numerically analysed for the range margins of the species and threshold values of competition strength which leads to the presence-absence of species. It is observed that the range margins are influenced by competition between species combined with environmental factors and the threshold values of competition strength correspond to transcritical bifurcation. Depending on the species’ competition strengths, the model exhibits coexistence and exclusion of species, mediated by weak and aggressive biotic interactions, respectively. It is observed that ecologically similar species competitively affect each other more than dissimilar species.

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Li, Yongfeng, Jingan Cui, and Xinyu Song. "Asymptotic behaviour of the non-autonomous competing two-species Lotka–Volterra models with impulsive effect." Journal of Biological Dynamics 3, no. 1 (2009): 58–72. http://dx.doi.org/10.1080/17513750802158661.

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Dubey, B., and J. Hussain. "Nonlinear models for the survival of two competing species dependent on resource in industrial environments." Nonlinear Analysis: Real World Applications 4, no. 1 (2003): 21–44. http://dx.doi.org/10.1016/s1468-1218(02)00011-1.

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Ellefsen, Erin, and Nancy Rodríguez. "Nonlocal Mechanistic Models in Ecology: Numerical Methods and Parameter Inferences." Applied Sciences 13, no. 19 (2023): 10598. http://dx.doi.org/10.3390/app131910598.

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Animals utilize their surroundings to make decisions on how to navigate and establish their territories. Some species gather information about competing groups by observing them from a distance, detecting scent markings, or relying on memories of encounters with rival populations. Gathering such information involves a nonlocal process, prompting the development of mechanistic models that incorporate nonlocal terms to explore species movement. These models, however, pose analytical and computational challenges. In this study, we focus on a multi-species advection–diffusion model that incorporates nonlocal advection. To efficiently compute solutions for this system involving a large number of interacting species, we introduce a numerical scheme using spectral methods. Additionally, we examine the influence of various parameters and interaction potentials on population densities. Our investigation aims to provide a method to identify the primary factors driving species movements, and we validate our approach using synthetic data.

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van Vuuren, Jan H., and John Norbury. "Conditions for permanence in well-known biological competition models." ANZIAM Journal 42, no. 2 (2000): 195–223. http://dx.doi.org/10.1017/s1446181100011871.

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AbstractReaction-diffusion systems are widely used to model the population densities of biological species competing for natural resources in their common habitat. It is often not too difficult to establish positive uniform upper bounds on solution components of such systems, but the task of establishing strictly positive uniform lower bounds (when they exist) can be quite troublesome. Two previously established criteria for the permanence (non-extinction and non-explosion) of solutions of general weakly-coupled competition-diffusion systems with diagonally convex reaction terms are used here as background to develop more easily verifiable and concrete conditions for permanence in various well-known competition diffusion models. These models include multi-component reaction-diffusion systems with (i) the by now classical Lotka-Volterra (logistic) reaction terms, (ii) higher order “logistic” interaction between the species, (iii) logistic-logarithmic reaction terms, (iv) Ayala-Gilpin-Ehrenfeld θ-interaction terms (which are used to model Drosophila competition), (v) logistic-exponential interaction between the species, (vi) Schoener-exploitation and (vii) modified Schoener-interference between the species. In (i) a known condition for permanence (for the ODE-system) is recovered, while in (ii)–(vii) new criteria for permanence are established.

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Kashchenko, S. A., E. A. Marushkina, and A. O. Tolbey. "Complicated Oscillations in the Problem of the Competition of Species." Interdisciplinary Journal Nonlinear Phenomena in Complex System 28, no. 1 (2025): 1–6. https://doi.org/10.5281/zenodo.15081369.

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Some families of mathematical models of biological populations competing for common food are considered. Dynamic properties of these models are investigated on an assumption that one or several populations are strongly prolific, which means that the corresponding malthusian coefficients are rather large. On the basis of a special asymptotic method a problem of behavior of the initial system solutions can be reduced to a significantly simpler problem of dynamics of the finite-dimensional mappings. In particular, it has been shown that irregular relaxation vibrations are typical for the solutions of these mappings and, as a result, for the solution of the initial equation systems. It is interesting to note that these vibrations are of large amplitudes. 

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Heske, Edward J., Richard S. Ostfeld, and William Z. Lidicker Jr. "Does social behavior drive vole cycles? An evaluation of competing models as they pertain to California voles." Canadian Journal of Zoology 66, no. 5 (1988): 1153–59. http://dx.doi.org/10.1139/z88-168.

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The literature contains a number of verbal and mathematical models that assert that social behavior drives the multiannual density cycles characteristic of many vole species. Many of the assumptions about vole behavior on which the models are based remain unverified. In this paper we briefly review these models and their underlying assumptions. We then use natural history data on the social behavior of California voles (Microtus californicus) to critically examine the plausibility of these assumptions. We do not attempt to explain vole cycles, but only to evaluate models that rely strongly on social behavior as a critical component. Our results indicate that (i) critical assumptions of the behavioral polymorphism, social stress, and social breakdown hypotheses are not met; (ii) some assumptions of the kin selection hypothesis are met whereas others are not; and (iii) assumptions of the habitat patchiness – dispersal hypothesis are met. However, published models of dispersal and habitat patchiness must invoke additional factors, such as resource depletion or predation, before cycles result. We conclude that social behavior is unlikely to be a driving force in the generation of cycles in the California vole. We hope that our approach will stimulate further research specifically directed at assumptions of these models.

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López-Gómez, Julián. "On the structure of the permanence region for competing species models with general diffusivities and transport effects." Discrete & Continuous Dynamical Systems - A 2, no. 4 (1996): 525–42. http://dx.doi.org/10.3934/dcds.1996.2.525.

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21

Wisheu, Irene C., and Paul Keddy. "Three Competing Models for Predicting the Size of Species Pools: A Test Using Eastern North American Wetlands." Oikos 76, no. 2 (1996): 253. http://dx.doi.org/10.2307/3546197.

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22

Kunakh, Olga, and Darya Kovalenko. "Fitting Competing Models of the Population Abundance Distribution: Land Snails from Nikopol Manganese Ore Basin Technosols." Ekológia (Bratislava) 38, no. 4 (2019): 367–81. http://dx.doi.org/10.2478/eko-2019-0027.

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AbstractThis paper examines the temporal dynamics of terrestrial mollusks of the Nikopol manganese ore basin technosols. The research was carried out at the Research Centre of the Dnipro Agrarian and Economic University in Pokrov (Ukraine). Sampling was carried out in 2012–2014 on four variants of artificial soil: formed on red-brown clays, on loess-like loams, on gray-green clays, and on humus-rich layer. The distribution of the number of individuals in a mollusk population was described by broken stick, Motomura, log-normal, Zipf, and Zipf-Mandelbrot models. It was shown that the series of models that best describe mollusk abundance distribution is specific for a particular species and technosols type and generally is invariant over time.

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23

Biging, Gregory S., and Samantha J. Gill. "Stochastic Models for Conifer Tree Crown Profiles." Forest Science 43, no. 1 (1997): 25–34. http://dx.doi.org/10.1093/forestscience/43.1.25.

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Abstract We perform a feasibility study of using stochastic models to describe the profile of tree crowns and to capture the stochastic nature of the tree crown form for five conifer species of the Sierra Nevada. In 70% of the cases investigated we found that we could model tree crown profiles as a quadratic or cubic trend in conjunction with a simple autoregressive moving average model (ARMA). In the remaining cases we used a quadratic or cubic trend in conjunction with white noise. These stochastic ARMA models are visually and statistically an improvement over using Euclidean geometric crown profile models. Competing models were judged by using Akaike's Information Criterion (AIC) to achieve a parsimonious model. It was found that first-order moving average MA(1) models or first-order autoregressive AR(1) models were adequate for modeling the majority of the cases studied and that these models were qualitatively similar. MA(1) models were preferred over the AR(1) models because less information is required to simulate them. For. Sci. 43(1):25-34.

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24

Rahbek, Carsten, Nicholas J. Gotelli, Robert K. Colwell, Gary L. Entsminger, Thiago Fernando L. V. B. Rangel, and Gary R. Graves. "Predicting continental-scale patterns of bird species richness with spatially explicit models." Proceedings of the Royal Society B: Biological Sciences 274, no. 1607 (2006): 165–74. http://dx.doi.org/10.1098/rspb.2006.3700.

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The causes of global variation in species richness have been debated for nearly two centuries with no clear resolution in sight. Competing hypotheses have typically been evaluated with correlative models that do not explicitly incorporate the mechanisms responsible for biotic diversity gradients. Here, we employ a fundamentally different approach that uses spatially explicit Monte Carlo models of the placement of cohesive geographical ranges in an environmentally heterogeneous landscape. These models predict species richness of endemic South American birds (2248 species) measured at a continental scale. We demonstrate that the principal single-factor and composite (species-energy, water-energy and temperature-kinetics) models proposed thus far fail to predict ( r 2 ⩽0.05) the richness of species with small to moderately large geographical ranges (first three range-size quartiles). These species constitute the bulk of the avifauna and are primary targets for conservation. Climate-driven models performed reasonably well only for species with the largest geographical ranges (fourth quartile) when range cohesion was enforced. Our analyses suggest that present models inadequately explain the extraordinary diversity of avian species in the montane tropics, the most species-rich region on Earth. Our findings imply that correlative climatic models substantially underestimate the importance of historical factors and small-scale niche-driven assembly processes in shaping contemporary species-richness patterns.

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25

Salinas-Ramos, Valeria B., Leonardo Ancillotto, Luca Cistrone, et al. "Artificial illumination influences niche segregation in bats." Environmental Pollution 284 (June 12, 2021): 117187. https://doi.org/10.5281/zenodo.13431676.

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(Uploaded by Plazi for the Bat Literature Project) Artificial light at night (ALAN) is a pervasive form of pollution largely affecting wildlife, from individual behaviour to community structure and dynamics. As nocturnal mammals, bats are often adversely affected by ALAN, yet some "light-opportunistic" species exploit it by hunting insects swarming near lights. Here we used two potentially competing pipistrelle species as models, Kuhl's (Pipistrellus kuhlii) and common (Pipistrellus pipistrellus) pipistrelles, both known to forage in artificially illuminated areas. We set our study in a mountainous area of central Italy, where only recently did the two species become syntopic. We applied spatial modelling and radiotracking to contrast potential vs. actual environmental preferences by the two pipistrelles. Species distribution models and niche analysis showed a large interspecific niche overlap, including a preference for illuminated areas, presenting a potential competition scenario. Pipistrellus pipistrellus association with ALAN, however, was weakened by adding P. kuhlii as a biotic variable to the model. Radiotracking showed that the two species segregated habitats at a small spatial scale and that P. kuhlii used artificially illuminated sites much more frequently than P. pipistrellus, despite both species potentially being streetlamp foragers. We demonstrate that ALAN influences niche segregation between two potentially competing species, confirming its pervasive effects on species and community dynamics, and provide an example of how light pollution and species' habitat preferences may weave a tapestry of complex ecological interactions.

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26

Salinas-Ramos, Valeria B., Leonardo Ancillotto, Luca Cistrone, et al. "Artificial illumination influences niche segregation in bats." Environmental Pollution 284 (June 7, 2021): 117187. https://doi.org/10.5281/zenodo.13431676.

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(Uploaded by Plazi for the Bat Literature Project) Artificial light at night (ALAN) is a pervasive form of pollution largely affecting wildlife, from individual behaviour to community structure and dynamics. As nocturnal mammals, bats are often adversely affected by ALAN, yet some "light-opportunistic" species exploit it by hunting insects swarming near lights. Here we used two potentially competing pipistrelle species as models, Kuhl's (Pipistrellus kuhlii) and common (Pipistrellus pipistrellus) pipistrelles, both known to forage in artificially illuminated areas. We set our study in a mountainous area of central Italy, where only recently did the two species become syntopic. We applied spatial modelling and radiotracking to contrast potential vs. actual environmental preferences by the two pipistrelles. Species distribution models and niche analysis showed a large interspecific niche overlap, including a preference for illuminated areas, presenting a potential competition scenario. Pipistrellus pipistrellus association with ALAN, however, was weakened by adding P. kuhlii as a biotic variable to the model. Radiotracking showed that the two species segregated habitats at a small spatial scale and that P. kuhlii used artificially illuminated sites much more frequently than P. pipistrellus, despite both species potentially being streetlamp foragers. We demonstrate that ALAN influences niche segregation between two potentially competing species, confirming its pervasive effects on species and community dynamics, and provide an example of how light pollution and species' habitat preferences may weave a tapestry of complex ecological interactions.

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27

Salinas-Ramos, Valeria B., Leonardo Ancillotto, Luca Cistrone, et al. "Artificial illumination influences niche segregation in bats." Environmental Pollution 284 (July 3, 2021): 117187. https://doi.org/10.5281/zenodo.13431676.

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(Uploaded by Plazi for the Bat Literature Project) Artificial light at night (ALAN) is a pervasive form of pollution largely affecting wildlife, from individual behaviour to community structure and dynamics. As nocturnal mammals, bats are often adversely affected by ALAN, yet some "light-opportunistic" species exploit it by hunting insects swarming near lights. Here we used two potentially competing pipistrelle species as models, Kuhl's (Pipistrellus kuhlii) and common (Pipistrellus pipistrellus) pipistrelles, both known to forage in artificially illuminated areas. We set our study in a mountainous area of central Italy, where only recently did the two species become syntopic. We applied spatial modelling and radiotracking to contrast potential vs. actual environmental preferences by the two pipistrelles. Species distribution models and niche analysis showed a large interspecific niche overlap, including a preference for illuminated areas, presenting a potential competition scenario. Pipistrellus pipistrellus association with ALAN, however, was weakened by adding P. kuhlii as a biotic variable to the model. Radiotracking showed that the two species segregated habitats at a small spatial scale and that P. kuhlii used artificially illuminated sites much more frequently than P. pipistrellus, despite both species potentially being streetlamp foragers. We demonstrate that ALAN influences niche segregation between two potentially competing species, confirming its pervasive effects on species and community dynamics, and provide an example of how light pollution and species' habitat preferences may weave a tapestry of complex ecological interactions.

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28

Salinas-Ramos, Valeria B., Leonardo Ancillotto, Luca Cistrone, et al. "Artificial illumination influences niche segregation in bats." Environmental Pollution 284 (July 10, 2021): 117187. https://doi.org/10.5281/zenodo.13431676.

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(Uploaded by Plazi for the Bat Literature Project) Artificial light at night (ALAN) is a pervasive form of pollution largely affecting wildlife, from individual behaviour to community structure and dynamics. As nocturnal mammals, bats are often adversely affected by ALAN, yet some "light-opportunistic" species exploit it by hunting insects swarming near lights. Here we used two potentially competing pipistrelle species as models, Kuhl's (Pipistrellus kuhlii) and common (Pipistrellus pipistrellus) pipistrelles, both known to forage in artificially illuminated areas. We set our study in a mountainous area of central Italy, where only recently did the two species become syntopic. We applied spatial modelling and radiotracking to contrast potential vs. actual environmental preferences by the two pipistrelles. Species distribution models and niche analysis showed a large interspecific niche overlap, including a preference for illuminated areas, presenting a potential competition scenario. Pipistrellus pipistrellus association with ALAN, however, was weakened by adding P. kuhlii as a biotic variable to the model. Radiotracking showed that the two species segregated habitats at a small spatial scale and that P. kuhlii used artificially illuminated sites much more frequently than P. pipistrellus, despite both species potentially being streetlamp foragers. We demonstrate that ALAN influences niche segregation between two potentially competing species, confirming its pervasive effects on species and community dynamics, and provide an example of how light pollution and species' habitat preferences may weave a tapestry of complex ecological interactions.

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29

Salinas-Ramos, Valeria B., Leonardo Ancillotto, Luca Cistrone, et al. "Artificial illumination influences niche segregation in bats." Environmental Pollution 284 (July 17, 2021): 117187. https://doi.org/10.5281/zenodo.13431676.

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(Uploaded by Plazi for the Bat Literature Project) Artificial light at night (ALAN) is a pervasive form of pollution largely affecting wildlife, from individual behaviour to community structure and dynamics. As nocturnal mammals, bats are often adversely affected by ALAN, yet some "light-opportunistic" species exploit it by hunting insects swarming near lights. Here we used two potentially competing pipistrelle species as models, Kuhl's (Pipistrellus kuhlii) and common (Pipistrellus pipistrellus) pipistrelles, both known to forage in artificially illuminated areas. We set our study in a mountainous area of central Italy, where only recently did the two species become syntopic. We applied spatial modelling and radiotracking to contrast potential vs. actual environmental preferences by the two pipistrelles. Species distribution models and niche analysis showed a large interspecific niche overlap, including a preference for illuminated areas, presenting a potential competition scenario. Pipistrellus pipistrellus association with ALAN, however, was weakened by adding P. kuhlii as a biotic variable to the model. Radiotracking showed that the two species segregated habitats at a small spatial scale and that P. kuhlii used artificially illuminated sites much more frequently than P. pipistrellus, despite both species potentially being streetlamp foragers. We demonstrate that ALAN influences niche segregation between two potentially competing species, confirming its pervasive effects on species and community dynamics, and provide an example of how light pollution and species' habitat preferences may weave a tapestry of complex ecological interactions.

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30

Visser, Hans. "The limits of economic theories and models." Central European Review of Economics and Management 4, no. 4 (2020): 47–68. http://dx.doi.org/10.29015/cerem.887.

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Aim: This article was written out of a felt need to reflect on the relationship between economic theories and models on the one hand and the empirical world as we experience it on the other. The question is in particular whether it is possible for economic models and theories to say anything definitive about the world we live in.  Design/Research methods: The article relies on professional publications, both within the field of economics and outside of it.  Conclusions/findings: There is much reason for humility, economic models and theories have hardly anything definitive to say about the empirical world, and there is a need for a more varied menu of theories and models and for a listening ear for the needs and fears of the population at large. The best we can do is discussing competing and conflicting views in a polite way. However, this requires a Sprachethik that looks more and more like an endangered species.  Originality/value of the article: Recent developments concerning the reach of economic models and theories are related to earlier discussions and a way forward is sketched 

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31

MARVÁ, M., J. C. POGGIALE, and R. BRAVO DE LA PARRA. "REDUCTION OF SLOW–FAST PERIODIC SYSTEMS WITH APPLICATIONS TO POPULATION DYNAMICS MODELS." Mathematical Models and Methods in Applied Sciences 22, no. 10 (2012): 1250025. http://dx.doi.org/10.1142/s021820251250025x.

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This work deals with the approximate reduction of a nonautonomous two time scales ordinary differential equations system with periodic fast dynamics. We illustrate this technique with the analysis of two models belonging to different fields in ecology. On the one hand, we deal with a two patches periodic predator–prey model with a refuge for prey. Considering migrations between patches to be faster than local interaction allows us to study a three-dimensional system by means of a two-dimensional one. On the other hand, a two time scales periodic eco-epidemic model is addressed by considering two competing species, one of them being affected by a periodic SIR epidemic process which is faster than inter-species interactions. The difference between time scales allows us to study the asymptotic behavior of the four-dimensional system by means of a planar, reduced one. Furthermore, we propose a methodology straightforwardly applicable to a very large class of two time scales periodic systems.

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32

Perez-Lopez, Jhean E., Diego A. Rueda-Gomez, and Elder J. Villamizar-Roa. "Existence of global solutions for cross-diffusion models in a fractional setting." Electronic Journal of Differential Equations 2023, no. 01-87 (2023): 77. http://dx.doi.org/10.58997/ejde.2023.77.

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This article is devoted to the analysis of a fractional chemotaxis model in $\mathbb{R}^N$ with a time fractional variation in the Caputo sense and a fractional spatial diffusion. This model encompasses the fractional Keller-Segel system [9] which describes the movement of living organisms towards higher concentration regions of chemical attractants, and a fractional Lotka-Volterra competition model [16] describing the competition interspecies in which one of the competing species avoids encounters with rivals by means of chemorepulsion. We prove product estimates in Besov-Morrey spaces and derive global estimates for mild solutions of the fractional heat equation. We use these results to prove the existence and uniqueness of global mild solutions for the differential system in a framework of Besov-Morrey spaces. For more information see https://ejde.math.txstate.edu/Volumes/2023/77/abstr.html

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Munteanu, Florian. "A study of a three-dimensional competitive Lotka–Volterra system." ITM Web of Conferences 34 (2020): 03010. http://dx.doi.org/10.1051/itmconf/20203403010.

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In this paper we will consider a community of three mutually competing species modeled by the Lotka–Volterra system: $$ {\left\{ {\dot x} \right._i} = {x_i}\left( {{b_i} - \sum\limits_{i = 1}^3 {{a_{ij}}{x_j}} } \right),i = 1,2,3 $$ where xi(t) is the population size of the i-th species at time t, Ẋi denote $${{dxi} \over {dt}}$$ and aij, bi are all strictly positive real numbers. This system of ordinary diﬀerential equations represent a class of Kolmogorov systems. This kind of systems is widely used in the mathematical models for the dynamics of population, like predator-prey models or diﬀerent models for the spread of diseases. A qualitative analysis of this Lotka-Volterra system based on dynamical systems theory will be performed, by studying the local behavior in equilibrium points and obtaining local dynamics properties.

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Tucker, Anton D., Colin J. Limpus, Keith R. McDonald, and Hamish I. McCallum. "Growth dynamics of freshwater crocodiles (Crocodylus johnstoni) in the Lynd River, Queensland." Australian Journal of Zoology 54, no. 6 (2006): 409. http://dx.doi.org/10.1071/zo06099.

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We analysed growth models for a population of Australian freshwater crocodiles (Crocodylus johnstoni). Competing growth models were tested with two data sets: individuals of known-age, and growth interval data from capture-recapture records. A von Bertalanffy function provided the best empirical fit of several growth models. The estimated asymptotic lengths (snout–vent length of males = 125.3 cm; females = 97.4 cm) agreed well with average lengths of the ten largest males and females in the population. Sexual size dimorphism in this species resulted from a combination of smaller mean length at maturity for females and a subsequent decline in female growth rate. Size dimorphism may result from individual trade-offs in age v. length at maturity as a consequence of sexual selection.

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Wenger, Seth J., James T. Peterson, Mary C. Freeman, Byron J. Freeman, and D. David Homans. "Stream fish occurrence in response to impervious cover, historic land use, and hydrogeomorphic factors." Canadian Journal of Fisheries and Aquatic Sciences 65, no. 7 (2008): 1250–64. http://dx.doi.org/10.1139/f08-046.

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We evaluated competing models explaining the occurrence of five stream fishes in an urbanizing watershed to determine the relative importance of (a) impervious surface and other indicators of current land use, (b) historic land use (e.g., agriculture, impoundments), and (c) hydrogeomorphic characteristics (e.g., stream size, elevation, geology). For four of five species, the best-supported models were those that included both current effective impervious cover and historic land use predictor variables, although models with only effective impervious cover were equally well supported for two of those species. For the best-supported models for three species, occurrence probability was predicted to approach zero at levels of development equivalent to about 2%–4% effective impervious cover in the surrounding region. Data were drawn from 357 fish collections made in the Etowah River basin, Georgia, USA, between 1998 and 2003 and analyzed using hierarchical logistic regression accounting for imperfect species detection. This is the first study we know of to examine the response of individual fish species to both increasing impervious cover and historic land use. Such individual species assessments will be increasingly necessary to guide policies for managing urban effects and preventing extirpations of sensitive species.

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Lester, Rebecca E., Ian T. Webster, Peter G. Fairweather, and William J. Young. "Linking water-resource models to ecosystem-response models to guide water-resource planning - an example from the Murray - Darling Basin, Australia." Marine and Freshwater Research 62, no. 3 (2011): 279. http://dx.doi.org/10.1071/mf09298.

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Objectively assessing ecological benefits of competing watering strategies is difficult. We present a framework of coupled models to compare scenarios, using the Coorong, the estuary for the Murray–Darling River system in South Australia, as a case study. The framework links outputs from recent modelling of the effects of climate change on water availability across the Murray–Darling Basin to a hydrodynamic model for the Coorong, and then an ecosystem-response model. The approach has significant advantages, including the following: (1) evaluating management actions is straightforward because of relatively tight coupling between impacts on hydrology and ecology; (2) scenarios of 111 years reveal the impacts of realistic climatic and flow variability on Coorong ecology; and (3) ecological impact is represented in the model by a series of ecosystem states, integrating across many organisms, not just iconic species. We applied the approach to four flow scenarios, comparing conditions without development, current water-use levels, and two predicted future climate scenarios. Simulation produced a range of hydrodynamic conditions and consequent distributions of ecosystem states, allowing managers to compare scenarios. This approach could be used with many climates and/or management actions for optimisation of flow delivery to environmental assets.

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Menden-Deuer, Susanne, Julie Rowlett, Medet Nursultanov, Sinead Collins, and Tatiana Rynearson. "Biodiversity of marine microbes is safeguarded by phenotypic heterogeneity in ecological traits." PLOS ONE 16, no. 8 (2021): e0254799. http://dx.doi.org/10.1371/journal.pone.0254799.

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Why, contrary to theoretical predictions, do marine microbe communities harbor tremendous phenotypic heterogeneity? How can so many marine microbe species competing in the same niche coexist? We discovered a unifying explanation for both phenomena by investigating a non-cooperative game that interpolates between individual-level competitions and species-level outcomes. We identified all equilibrium strategies of the game. These strategies represent the probability distribution of competitive abilities (e.g. traits) and are characterized by maximal phenotypic heterogeneity. They are also neutral towards each other in the sense that an unlimited number of species can co-exist while competing according to the equilibrium strategies. Whereas prior theory predicts that natural selection would minimize trait variation around an optimum value, here we obtained a mathematical proof that species with maximally variable traits are those that endure. This discrepancy may reflect a disparity between predictions from models developed for larger organisms in contrast to our microbe-centric model. Rigorous mathematics proves that phenotypic heterogeneity is itself a mechanistic underpinning of microbial diversity. This discovery has fundamental ramifications for microbial ecology and may represent an adaptive reservoir sheltering biodiversity in changing environmental conditions.

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Brown, Paul L., and Scott J. Markich. "An Evaluation of Metal Binding Constants to Cell Surface Receptors in Freshwater Organisms, and Their Application in Biotic Ligand Models to Predict Metal Toxicity." Water 16, no. 20 (2024): 2999. http://dx.doi.org/10.3390/w16202999.

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Biotic ligand models (BLMs) predict the toxicity of metals in aquatic environments by accounting for metal interactions with cell surface receptors (biotic ligands) in organisms, including water chemistry (metal speciation) and competing cations. Metal binding constants (log KMBL values), which indicate the affinity of metals for cell surface receptors, are fundamental to BLMs, but have only been reported for a few commonly investigated metals and freshwater species. This review evaluated literature toxicity and uptake data for seven key metals (cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), lead (Pb), uranium (U), and zinc (Zn)) and four key competing cations (protons (H), calcium (Ca), magnesium (Mg), and sodium (Na)), to derive average metal binding constants for freshwater organisms/taxa. These constants will improve current BLMs for Cd, Cu, Ni, Pb, and Zn, and aid in developing new BLMs for Co and U. The derived metal binding constants accurately predicted metal toxicity for a wide range of freshwater organisms (75–88% of data were within a factor of two and 88–98% of data were within a factor of three of the ideal 1:1 agreement line), when considering metal speciation, competing cations and the fraction of cell receptors ((fC)M50%) occupied by the metal at the median (50%) effect concentration (EC50). For many organisms, toxicity occurs when 50% of cell surface receptors are occupied by the metal, though this threshold can vary. Some organisms exhibit toxicity with less than 50% receptor occupancy, while others with protective mechanisms show reduced toxicity, even with similar log KMBL values. For Cu, U, and Pb, the toxic effect of the metal hydroxide (as MOH+) must be considered in addition to the free metal ion (M2+), as these metals hydrolyse in circumneutral freshwaters (pH 5.5 to 8.5), contributing to toxicity.

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Gourbiere, Sébastien, Pierre Auger, Jean Luc Chassé, and Bruno Faivre. "Extinction Waves in Spatial Population Dynamic Models — the Case of two Sibling Bird Species H. Icterina and H. Polygotta." Journal of Biological Systems 05, no. 03 (1997): 359–74. http://dx.doi.org/10.1142/s0218339097000229.

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Two spatial models of populations dynamics are presented to study the evolution of spatial distributions of two sibling species. We defined firstly an interspecific competition model and secondly a one predator-two preys model. They are constituted of a two dimensional discrete set of cells.Initially, the two competing or prey species occupy two complementary areas with common zone and the predator is regularly distributed. Populations of each cell are assumed to firstly have local interactions of competition or selective predation and secondly disperse to the four nearest neighbouring cells. We establish a typology of spatial structures obtained from both interspecific competition and selective predation. These two types of interactions are able to create a sympatric zone and to cause its motion.

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Hincal, Evren, Shorsh Mohammed, and Bilgen Kaymakamzade. "Stability analysis of an ecoepidemiological model consisting of a prey and tow competing predators with Si-disease in prey and toxicant." BULLETIN OF THE KARAGANDA UNIVERSITY-MATHEMATICS 99, no. 3 (2020): 55–61. http://dx.doi.org/10.31489/2020m3/55-61.

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In the present paper, we study two eco-epidemiological models. The first one consists of a prey and two competing predators with SI-disease in prey species spreading by contacts between susceptible prey and infected prey. This model assumes linear functional response. The second model is the modification of the first one when the effect of toxicant is taken into account. In this paper, we examine the dynamical behavior of non-survival and free equilibrium points of our proposed model.

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Cantrell, Robert Stephen. "Global higher bifurcations in coupled systems of nonlinear eigenvalue problems." Proceedings of the Royal Society of Edinburgh: Section A Mathematics 106, no. 1-2 (1987): 113–20. http://dx.doi.org/10.1017/s0308210500018242.

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SynopsisCoexistent steady-state solutions to a Lotka–Volterra model for two freely-dispersing competing species have been shown by several authors to arise as global secondary bifurcation phenomena. In this paper we establish conditions for the existence of global higher dimensional n-ary bifurcation in general systems of multiparameter nonlinear eigenvalue problems which preserve the coupling structure of diffusive steady-state Lotka–Volterra models. In establishing our result, we mainly employ the recently-developed multidimensional global multiparameter theory of Alexander–Antman. Conditions for ternary steady-state bifurcation in the three species diffusive competition model are given as an application of the result.

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Rheims, Cristina, Bernhard Huber, and Antonio Brescovit. "Exaggerated female genitalia in two new spider species (Araneae: Pholcidae), with comments on genital evolution by female choice versus antagonistic coevolution." Insect Systematics & Evolution 36, no. 3 (2005): 285–92. http://dx.doi.org/10.1163/187631205788838375.

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AbstractTwo new species are described that are remarkable in having exaggerated female genitalia: Mesabolivar samatiaguassu sp. n. and M. cuarassu sp. n.. Comparative evidence as well as size measurements of male and female structures suggest that the exaggerated female external genitalia correlate functionally with elongated male cheliceral apophyses. These morphological findings are discussed in the light of competing models of genital evolution. Luring mating acts, female cooperative behaviour and morphology, as well as the probable costs associated with the female structures argue against the antagonistic coevolution model and favour sexual selection by cryptic female choice.

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Yoshioka, Hidekazu, and Yumi Yoshioka. "On a non-standard two-species stochastic competing system and a related degenerate parabolic equation." ANZIAM Journal 61 (June 7, 2020): C1—C14. http://dx.doi.org/10.21914/anziamj.v61i0.15040.

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We propose and analyse a new stochastic competing two-species population dynamics model. Competing algae population dynamics in river environments, an important engineering problem, motivates this model. The algae dynamics are described by a system of stochastic differential equations with the characteristic that the two populations are competing with each other through the environmental capacities. Unique existence of the uniformly bounded strong solution is proven and an attractor is identified. The Kolmogorov backward equation associated with the population dynamics is formulated and its unique solvability in a Banach space with a weighted norm is discussed. Our mathematical analysis results can be effectively utilized for a foundation of modelling, analysis, and control of the competing algae population dynamics.   References S. Cai, Y. Cai, and X. Mao. A stochastic differential equation SIS epidemic model with two correlated brownian motions. Nonlin. Dyn., 97(4):2175–2187, 2019. doi:10.1007/s11071-019-05114-2. S. Cai, Y. Cai, and X. Mao. A stochastic differential equation SIS epidemic model with two independent brownian motions. J. Math. Anal. App., 474(2):1536–1550, 2019. doi:10.1016/j.jmaa.2019.02.039. U. Callies, M. Scharfe, and M. Ratto. Calibration and uncertainty analysis of a simple model of silica-limited diatom growth in the Elbe river. Ecol. Mod., 213(2):229–244, 2008. doi:10.1016/j.ecolmodel.2007.12.015. M. G. Crandall, H. Ishii, and P. L. Lions. User's guide to viscosity solutions of second order partial differential equations. Bull. Am. Math. Soc., 27(1):229–244, 1992. doi:10.1090/S0273-0979-1992-00266-5. N. H. Du and V. H. Sam. Dynamics of a stochastic Lotka–Volterra model perturbed by white noise. J. Math. Anal. App., 324(1):82–97, 2006. doi:10.1016/j.jmaa.2005.11.064. P. Grandits, R. M. Kovacevic, and V. M. Veliov. Optimal control and the value of information for a stochastic epidemiological SIS model. J. Math. Anal. App., 476(2):665–695, 2019. doi:10.1016/j.jmaa.2019.04.005. B. Horvath and O. Reichmann. Dirichlet forms and finite element methods for the SABR model. SIAM J. Fin. Math., 9(2):716–754, 2018. doi:10.1137/16M1066117. J. Hozman and T. Tichy. DG framework for pricing european options under one-factor stochastic volatility models. J. Comput. Appl. Math., 344:585–600, 2018. doi:10.1016/j.cam.2018.05.064. G. Lan, Y. Huang, C. Wei, and S. Zhang. A stochastic SIS epidemic model with saturating contact rate. Physica A, 529(121504):1–14, 2019. doi:10.1016/j.physa.2019.121504. J. L. Lions and E. Magenes. Non-homogeneous Boundary Value Problems and Applications (Vol. 1). Springer Berlin Heidelberg, 1972. doi:10.1007/978-3-642-65161-8. J. Lv, X. Zou, and L. Tian. A geometric method for asymptotic properties of the stochastic Lotka–Volterra model. Commun. Nonlin. Sci. Numer. Sim., 67:449–459, 2019. doi:10.1016/j.cnsns.2018.06.031. S. Morin, M. Coste, and F. Delmas. A comparison of specific growth rates of periphytic diatoms of varying cell size under laboratory and field conditions. Hydrobiologia, 614(1):285–297, 2008. doi:10.1007/s10750-008-9513-y. B. \T1\O ksendal. Stochastic Differential Equations. Springer Berlin Heidelberg, 2003. doi:10.1007/978-3-642-14394-6. O. Oleinik and E. V. Radkevic. Second-order Equations with Nonnegative Characteristic Form. Springer Boston, 1973. doi:10.1007/978-1-4684-8965-1. S. Peng. Nonlinear Expectations and Stochastic Calculus under Uncertainty: with Robust CLT and G-Brownian Motion. Springer-Verlag Berlin Heidelberg, 2019. doi:10.1007/978-3-662-59903-7. T. S. Schmidt, C. P. Konrad, J. L. Miller, S. D. Whitlock, and C. A. Stricker. Benthic algal (periphyton) growth rates in response to nitrogen and phosphorus: parameter estimation for water quality models. J. Am. Water Res. Ass., 2019. doi:10.1111/1752-1688.12797. Y. Toda and T. Tsujimoto. Numerical modeling of interspecific competition between filamentous and nonfilamentous periphyton on a flat channel bed. Landscape Ecol. Eng., 6(1):81–88, 2010. doi:10.1007/s11355-009-0093-4. H. Yoshioka, Y. Yaegashi, Y. Yoshioka, and K. Tsugihashi. Optimal harvesting policy of an inland fishery resource under incomplete information. Appl. Stoch. Models Bus. Ind., 35(4):939–962, 2019. doi:10.1002/asmb.2428.

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Rothschild, Jeremy, Tianyi Ma, Joshua N. Milstein, and Anton Zilman. "Spatial exclusion leads to “tug-of-war” ecological dynamics between competing species within microchannels." PLOS Computational Biology 19, no. 12 (2023): e1010868. http://dx.doi.org/10.1371/journal.pcbi.1010868.

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Competition is ubiquitous in microbial communities, shaping both their spatial and temporal structure and composition. Classical minimal models of competition, such as the Moran model, have been employed in ecology and evolutionary biology to understand the role of fixation and invasion in the maintenance of population diversity. Informed by recent experimental studies of cellular competition in confined spaces, we extend the Moran model to incorporate mechanical interactions between cells that divide within the limited space of a one-dimensional open microchannel. The model characterizes the skewed collective growth of the cells dividing within the channel, causing cells to be expelled at the channel ends. The results of this spatial exclusion model differ significantly from those of its classical well-mixed counterpart. The mean time to fixation of a species is greatly accelerated, scaling logarithmically, rather than algebraically, with the system size, and fixation/extinction probability sharply depends on the species’ initial fractional abundance. By contrast, successful takeovers by invasive species, whether through mutation or immigration, are substantially less likely than in the Moran model. We also find that the spatial exclusion tends to attenuate the effects of fitness differences on the fixation times and probabilities. We find that these effects arise from the combination of the quasi-neutral “tug-of-war” diffusion dynamics of the inter-species boundary around an unstable equipoise point and the quasi-deterministic avalanche dynamics away from the fixed point. These results, which can be tested in microfluidic monolayer devices, have implications for the maintenance of species diversity in dense bacterial and cellular ecosystems where spatial exclusion is central to the competition, such as in organized biofilms or intestinal crypts.

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Kunakh, O. N., S. S. Kramarenko, A. V. Zhukov, A. S. Kramarenko, and N. V. Yorkina. "Fitting competing models and evaluation of model parameters of the abundance distribution of the land snail Vallonia pulchella (Pulmonata, Valloniidae)." Regulatory Mechanisms in Biosystems 9, no. 2 (2018): 198–202. http://dx.doi.org/10.15421/021829.

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This paper summarizes the mechanisms behind the patterning of the intra-population abundance distribution of the land snail Vallonia pulchella (Müller, 1774). The molluscs were collected in recultivated soil formed on red-brown clays (Pokrov, Ukraine). Data obtained in this study reveal that V. pulchella population abundance ranges from 1 to 13 individuals per 100 g of soil sample. To obtain estimates of the mean, three models were used: the model of the arithmetic mean, the Poisson model and a log-normal model. The arithmetic mean of the occurrence of this species during the study period was 1.84 individuals/sample. Estimation of the average number of molluscs in one sample calculated using the Poisson model is lower and equals 1.40 individuals/sample. The distribution of the number of individuals in a population was described by the graphics "rank – abundance". The individual sample plot sites with molluscs may be regarded as equivalents of individual species in the community. For the analysis, the following models were used: broken sticks model, niche preemption model, log-normal model, Zipf model, and Zipf-Mandelbrot model. Applying the log-normal distribution gives a lower estimate of the mean density at 1.28 individuals/sample. Median value and mode is estimated at 1.00 individuals/sample. The Zipf-Mandelbrot model was shown as the most adequate to describe distribution of the V. pulchella population within the study area. The Zipf-Mandelbrot model belongs to the family of so-called non-Gaussian distributions. This means that the sample statistics do not possess asymptotic properties and by increasing the sample size, they tend to infinity, and are not close to the values of the general population. Therefore, the average value of the random variable that describes the non-Gaussian distribution has no statistical meaning. From an environmental point of view, this means that within the study area the capacity of the habitat is large, and for some combination of environmental conditions the rapid growth of the abundance of a given species is possible.

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Barbosa, Lorena Oliveira, Emanuel Arnoni Costa, Cristine Tagliapietra Schons, César Augusto Guimarães Finger, Veraldo Liesenberg, and Polyanna da Conceição Bispo. "Individual Tree Basal Area Increment Models for Brazilian Pine (Araucaria angustifolia) Using Artificial Neural Networks." Forests 13, no. 7 (2022): 1108. http://dx.doi.org/10.3390/f13071108.

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This research aimed to develop statistical models to predict basal area increment (BAI) for Araucaria angustifolia using Artificial Neural Networks (ANNs). Tree species were measured for their biometric variables and identified at the species level. The data were subdivided into three groups: (1) intraspecific competition with A. angustifolia; (2) the first group of species that causes interspecific competition with A. angustifolia; and (3) the second group of species that causes interspecific competition with A. angustifolia. We calculated both the dependent and independent distance and the described competition indices, considering the impact of group stratification. Multi-layer Perceptron (MLP) ANN was structured for modeling. The main results were that: (i) the input variables size and competition were the most significant, allowing us to explain up to 77% of the A. angustifolia BAI variations; (ii) the spatialization of the competing trees contributed significantly to the representation of the competitive status; (iii) the separate variables for each competition group improved the performance of the models; and (iv) besides the intraspecific competition, the interspecific competition also proved to be important to consider. The ANN developed showed precision and generalization, suggesting it could describe the increment of a species common in native forests in Southern Brazil and with potential for upcoming forest management initiatives.

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Pacciani-Mori, Leonardo, Samir Suweis, Amos Maritan, and Andrea Giometto. "Constrained proteome allocation affects coexistence in models of competitive microbial communities." ISME Journal 15, no. 5 (2021): 1458–77. http://dx.doi.org/10.1038/s41396-020-00863-0.

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AbstractMicrobial communities are ubiquitous and play crucial roles in many natural processes. Despite their importance for the environment, industry and human health, there are still many aspects of microbial community dynamics that we do not understand quantitatively. Recent experiments have shown that the structure and composition of microbial communities are intertwined with the metabolism of the species that inhabit them, suggesting that properties at the intracellular level such as the allocation of cellular proteomic resources must be taken into account when describing microbial communities with a population dynamics approach. In this work, we reconsider one of the theoretical frameworks most commonly used to model population dynamics in competitive ecosystems, MacArthur’s consumer-resource model, in light of experimental evidence showing how proteome allocation affects microbial growth. This new framework allows us to describe community dynamics at an intermediate level of complexity between classical consumer-resource models and biochemical models of microbial metabolism, accounting for temporally-varying proteome allocation subject to constraints on growth and protein synthesis in the presence of multiple resources, while preserving analytical insight into the dynamics of the system. We first show with a simple experiment that proteome allocation needs to be accounted for to properly understand the dynamics of even the simplest microbial community, i.e. two bacterial strains competing for one common resource. Then, we study our consumer-proteome-resource model analytically and numerically to determine the conditions that allow multiple species to coexist in systems with arbitrary numbers of species and resources.

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Alsolami, Abdulrahman Ali, and Miled El Hajji. "Mathematical Analysis of a Bacterial Competition in a Continuous Reactor in the Presence of a Virus." Mathematics 11, no. 4 (2023): 883. http://dx.doi.org/10.3390/math11040883.

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In this paper, we discuss the competition of two species for a single essential growth-limiting nutriment with viral infection that affects only the first species. Although the classical models without viral infection suggest competitive exclusion, this model exhibits the stable coexistence of both species. We reduce the fourth-dimension proposed model to a three-dimension one. Thus, the coexistence of the two competing species is demonstrated using the theory of uniform persistence applied to the three-variable reduced system. We prove that there is no coexistence of both species without the presence of the virus and the satisfaction of some assumptions on the growth rates of species. Finally, we give some numerical simulations to confirm the obtained theoretical findings.

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Ghosh, Preetam, Pratip Rana, Vijayaraghavan Rangachari, Jhinuk Saha, Edward Steen та Ashwin Vaidya. "A game-theoretic approach to deciphering the dynamics of amyloid- β aggregation along competing pathways". Royal Society Open Science 7, № 4 (2020): 191814. http://dx.doi.org/10.1098/rsos.191814.

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Aggregation of amyloid- β (A β ) peptides is a significant event that underpins Alzheimer's disease (AD). A β aggregates, especially the low-molecular weight oligomers, are the primary toxic agents in AD pathogenesis. Therefore, there is increasing interest in understanding their formation and behaviour. In this paper, we use our previously established results on heterotypic interactions between A β and fatty acids (FAs) to investigate off-pathway aggregation under the control of FA concentrations to develop a mathematical framework that captures the mechanism. Our framework to define and simulate the competing on- and off-pathways of A β aggregation is based on the principles of game theory. Together with detailed simulations and biophysical experiments, our models describe the dynamics involved in the mechanisms of A β aggregation in the presence of FAs to adopt multiple pathways. Specifically, our reduced-order computations indicate that the emergence of off- or on-pathway aggregates are tightly controlled by a narrow set of rate constants, and one could alter such parameters to populate a particular oligomeric species. These models agree with the detailed simulations and experimental data on using FA as a heterotypic partner to modulate the temporal parameters. Predicting spatio-temporal landscape along competing pathways for a given heterotypic partner such as lipids is a first step towards simulating scenarios in which the generation of specific ‘conformer strains’ of A β could be predicted. This approach could be significant in deciphering the mechanisms of amyloid aggregation and strain generation, which are ubiquitously observed in many neurodegenerative diseases.

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Sneddon, Lynne U. "Evolution of nociception and pain: evidence from fish models." Philosophical Transactions of the Royal Society B: Biological Sciences 374, no. 1785 (2019): 20190290. http://dx.doi.org/10.1098/rstb.2019.0290.

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In order to survive, animals must avoid injury and be able to detect potentially damaging stimuli via nociceptive mechanisms. If the injury is accompanied by a negative affective component, future behaviour should be altered and one can conclude the animal experienced the discomfort associated with pain. Fishes are the most successful vertebrate group when considering the number of species that have filled a variety of aquatic niches. The empirical evidence for nociception in fishes from the underlying molecular biology, neurobiology and anatomy of nociceptors through to whole animal behavioural responses is reviewed to demonstrate the evolutionary conservation of nociception and pain from invertebrates to vertebrates. Studies in fish have shown that the biology of the nociceptive system is strikingly similar to that found in mammals. Further, potentially painful events result in behavioural and physiological changes such as reduced activity, guarding behaviour, suspension of normal behaviour, increased ventilation rate and abnormal behaviours which are all prevented by the use of pain-relieving drugs. Fish also perform competing tasks less well when treated with a putative painful stimulus. Therefore, there is ample evidence to demonstrate that it is highly likely that fish experience pain and that pain-related behavioural changes are conserved across vertebrates. This article is part of the Theo Murphy meeting issue ‘Evolution of mechanisms and behaviour important for pain’.

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Journal articles on the topic 'Models for competing specie'

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