Adaptive explanation in socio-ecology: lessons from the Equidae.
Abstract: Socio-ecological explanations for intra- and interspecific variation in the social and spatial organization of animals predominate in the scientific literature. The socio-ecological model, developed first for the Bovidae and Cervidae, is commonly applied more widely to other groups including the Equidae. Intraspecific comparisons are particularly valuable because they allow the role of environment and demography on social and spatial organization to be understood while controlling for phylogeny or morphology which confound interspecific comparisons. Feral horse (Equus caballus Linnaeus 1758) populations with different demography inhabit a range of environments throughout the world. I use 56 reports to obtain 23 measures or characteristics of the behaviour and the social and spatial organization of 19 feral horse populations in which the environment, demography, management, research effort and sample size are also described. Comparison shows that different populations had remarkably similar social and spatial organization and that group sizes and composition, and home range sizes varied as much within as between populations. I assess the few exceptions to uniformity and conclude that they are due to the attributes of the studies themselves, particularly to poor definition of terms and inadequate empiricism, rather than to the environment or demography per se. Interspecific comparisons show that equid species adhere to their different social and spatial organizations despite similarities in their environments and even when species are sympatric. Furthermore, equid male territoriality has been ill-defined in previous studies, observations presented as evidence of territoriality are also found in non-territorial equids, and populations of supposedly territorial species demonstrate female defence polygyny. Thus, territoriality may not be a useful categorization in the Equidae. Moreover, although equid socio-ecologists have relied on the socio-ecological model derived from the extremely diverse Bovidae and Cervidae for explanations of variation in equine society, the homomorphic, but large and polygynous, and monogeneric Equidae do not support previous socio-ecological explanations for relationships between body size, mating system and sexual dimorphism in ungulates. Consequently, in spite of the efforts of numerous authors during the past two decades, functional explanations of apparent differences in feral horse and equid social and spatial organization and behaviour based on assumptions of their current utility in the environmental or demographic context remain unconvincing. Nevertheless, differences in social cohesion between species that are insensitive to intra- and interspecific variation in habitat and predation pressure warrant explanation. Thus, I propose alternative avenues of inquiry including testing for species-specific differences in inter-individual aggression and investigating the role of phylogenetic constraints in equine society. The Equidae are evidence of the relative importance of phylogeny and biological structure, and unimportance of the present-day environment, in animal behaviour and social and spatial organization.
Publication Date: 2000-03-31 PubMed ID: 10740891DOI: 10.1017/s0006323199005411Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
- Review
Summary
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This research article examines the influence of environment and demography on social and spatial organization behaviors within various feral horse populations, concluding that there is not one firmly ingrained socio-ecological explanation for differences in these behaviors.
Understanding the Socio-ecological Model with the Equidae
- The study delves into the socio-ecological model, which was first developed for the Bovidae and Cervidae. The model is typically applied to other groups, including the Equidae.
- Feral horses present an ideal case for intraspecific comparisons, which help researchers understand the influence of environment and demography on social and spatial organization without being confounded by others factors like phylogeny or morphology.
- The researcher used 56 reports to derive 23 measures of behaviour and social and spatial organization within 19 feral horse populations, noting environment, demography, management, research effort and sample size.
Comparison and Contrasts within Feral Horse Populations
- The study found that varying feral horse populations had largely similar social and spatial organization, and the differences in home range sizes and group formations appeared to be as diverse within populations as they were between different populations.
- The variations that did exist were attributed more to the individual studies’ shortcomings, such as imprecise definitions and insufficient empirical data, rather than differences in environment or demography.
- Interspecies comparisons revealed that even with similar environment conditions, equid species maintained distinct social and spatial organizations, speculating that male territoriality might not be a significant factor in equid behaviour.
Reassessing the Socio-ecological Model
- The study found that the existing socio-ecological model, which utilizes information from highly diverse Bovidae and Cervidae, is likely insufficient to explain equine society, as horse species are quite different from these groups in many ways. Therefore, the article proposes that the relationships this model constructs between body size, mating system, and sexual dimorphism are not completely transferable to ungulates.
- In conclusion, this article suggests that past efforts to explain differences in social and spatial organization based on their utility in varying environmental or demographic conditions are unconvincing.
Proposing New Avenues of Inquiry
- The research proposed alternative lines of inquiry to explain social cohesion differences among species that persist regardless of varying habitat and predation pressure. This includes testing species-specific differences in aggression levels between individuals and exploring the influence of phylogenetic constraints on equine society.
- The conclusion is made that, in Equidae, phylogeny and biological structure carry far greater importance than the specific characteristics of the present-day environment in determining animal behaviour and social and spatial organization.
Cite This Article
APA
Linklater WL.
(2000).
Adaptive explanation in socio-ecology: lessons from the Equidae.
Biol Rev Camb Philos Soc, 75(1), 1-20.
https://doi.org/10.1017/s0006323199005411 Publication
Researcher Affiliations
- Institute of Natural Resources, Massey University, Palmerston North, New Zealand.
MeSH Terms
- Adaptation, Physiological
- Animals
- Ecology
- Equidae / physiology
- Female
- Male
- Phylogeny
Citations
This article has been cited 28 times.- Krueger K, Gruentjens T, Hempel E. Wolf contact in horses at permanent pasture in Germany. PLoS One 2023;18(8):e0289767.
- Sharif MB, Fitak RR, Wallner B, Orozco-terWengel P, Frewin S, Fremaux M, Mohandesan E. Reconstruction of the Major Maternal and Paternal Lineages in the Feral New Zealand Kaimanawa Horses. Animals (Basel) 2022 Dec 12;12(24).
- Brucks D, Härterich A, König von Borstel U. Horses wait for more and better rewards in a delay of gratification paradigm. Front Psychol 2022;13:954472.
- Koons DN, Riecke TV, Boomer GS, Sedinger BS, Sedinger JS, Williams PJ, Arnold TW. A niche for null models in adaptive resource management. Ecol Evol 2022 Jan;12(1):e8541.
- Fehlmann G, O'riain MJ, FÜrtbauer I, King AJ. Behavioral Causes, Ecological Consequences, and Management Challenges Associated with Wildlife Foraging in Human-Modified Landscapes. Bioscience 2021 Jan;71(1):40-54.
- Maeda T, Ochi S, Ringhofer M, Sosa S, Sueur C, Hirata S, Yamamoto S. Aerial drone observations identified a multilevel society in feral horses. Sci Rep 2021 Jan 8;11(1):71.
- Gambini A, Duque Rodríguez M, Rodríguez MB, Briski O, Flores Bragulat AP, Demergassi N, Losinno L, Salamone DF. Horse ooplasm supports in vitro preimplantation development of zebra ICSI and SCNT embryos without compromising YAP1 and SOX2 expression pattern. PLoS One 2020;15(9):e0238948.
- Aune A, Fenner K, Wilson B, Cameron E, McLean A, McGreevy P. Reported Behavioural Differences between Geldings and Mares Challenge Sex-Driven Stereotypes in Ridden Equine Behaviour. Animals (Basel) 2020 Mar 2;10(3).
- Kydd E, Padalino B, Henshall C, McGreevy P. An analysis of equine round pen training videos posted online: Differences between amateur and professional trainers. PLoS One 2017;12(9):e0184851.
- Maigrot AL, Hillmann E, Anne C, Briefer EF. Vocal expression of emotional valence in Przewalski's horses (Equus przewalskii). Sci Rep 2017 Aug 18;7(1):8779.
- Gersick AS, Rubenstein DI. Physiology modulates social flexibility and collective behaviour in equids and other large ungulates. Philos Trans R Soc Lond B Biol Sci 2017 Aug 19;372(1727).
- Ringhofer M, Inoue S, Mendonça RS, Pereira C, Matsuzawa T, Hirata S, Yamamoto S. Comparison of the social systems of primates and feral horses: data from a newly established horse research site on Serra D'Arga, northern Portugal. Primates 2017 Oct;58(4):479-484.
- Goffe AS, Zinner D, Fischer J. Sex and friendship in a multilevel society: behavioural patterns and associations between female and male Guinea baboons. Behav Ecol Sociobiol 2016;70:323-336.
- Burger D, Dolivo G, Wedekind C. Ejaculate Characteristics Depend on Social Environment in the Horse (Equus caballus). PLoS One 2015;10(11):e0143185.
- Bourjade M, Thierry B, Hausberger M, Petit O. Is leadership a reliable concept in animals? An empirical study in the horse. PLoS One 2015;10(5):e0126344.
- Lemasson A, Remeuf K, Trabalon M, Cuir F, Hausberger M. Mares prefer the voices of highly fertile stallions. PLoS One 2015;10(2):e0118468.
- Trettin J, Seyferth T, Heinze J. Behavioral plasticity in ant queens: environmental manipulation induces aggression among normally peaceful queens in the socially polymorphic ant Leptothorax acervorum. PLoS One 2014;9(4):e95153.
- Marjamäki PH, Contasti AL, Coulson TN, McLoughlin PD. Local density and group size interacts with age and sex to determine direction and rate of social dispersal in a polygynous mammal. Ecol Evol 2013 Sep;3(9):3073-82.
- Thierry B. Identifying constraints in the evolution of primate societies. Philos Trans R Soc Lond B Biol Sci 2013 May 19;368(1618):20120342.
- Kappeler PM, Barrett L, Blumstein DT, Clutton-Brock TH. Constraints and flexibility in mammalian social behaviour: introduction and synthesis. Philos Trans R Soc Lond B Biol Sci 2013 May 19;368(1618):20120337.
- Henselek Y, Fischer J, Schloegl C. Does the stimulus type influence horses' performance in a quantity discrimination task?. Front Psychol 2012;3:504.
- Cameron EZ, Setsaas TH, Linklater WL. Social bonds between unrelated females increase reproductive success in feral horses. Proc Natl Acad Sci U S A 2009 Aug 18;106(33):13850-3.
- Grange S, Duncan P, Gaillard JM. Poor horse traders: large mammals trade survival for reproduction during the process of feralization. Proc Biol Sci 2009 May 22;276(1663):1911-9.
- Gray ME. An infanticide attempt by a free-roaming feral stallion (Equus caballus). Biol Lett 2009 Feb 23;5(1):23-5.
- Roig-Pons M, Bachmann I, Freymond SB. Impact of feeding strategies on the welfare and behaviour of horses in groups: An experimental study. PLoS One 2025;20(6):e0325928.
- Du W, Sun Q, Hu S, Yu P, Kan S, Zhang W. Equus mitochondrial pangenome reveals independent domestication imprints in donkeys and horses. Sci Rep 2025 Feb 25;15(1):6803.
- Bernátková A, Oyunsaikhan G, Šimek J, Komárková M, Ceacero F. Social networks of reintroduced Przewalski's horses in the Great Gobi B Strictly Protected Area (Mongolia). Curr Zool 2024 Apr;70(2):182-194.
- Hults CM, Francis RC, Clint EK, Smith W, Sober ER, Garland T Jr, Rhodes JS. Still little evidence sex differences in spatial navigation are evolutionary adaptations. R Soc Open Sci 2024 Jan;11(1):231532.
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