Bowyer R Terry, McCullough Dale R, Rachlow Janet L, Ciuti Simone, Whiting Jericho C
Institute of Arctic Biology University of Alaska Fairbanks Fairbanks AK USA.
Department of Environmental Science, Policy and Management University of California Berkeley CA USA.
Ecol Evol. 2020 Apr 15;10(11):5160-5178. doi: 10.1002/ece3.6246. eCollection 2020 Jun.
Ungulates exhibit diverse mating systems that range from monogamous pair territories to highly polygynous leks. We review mating systems and behaviors across ungulates and offer a new approach synthesizing how interacting factors may shape those mating systems. Variability exists in mating systems among and within species of ungulates and likely is affected by predation risk, availability of resources (food and mates), habitat structure, and sociality. Ungulate mating systems may be labile as a consequence of the varying strength of those interacting factors. In addition, degree of polygyny and sexual dimorphism in size are associated with the evolution of mating systems. Neither male-male combat nor paternal care, however, can completely explain differences in sexual size dimorphism for ungulates, a necessary component in understanding the development of some mating systems. Whatever the evolutionary pathway, sexual segregation limits paternal care allowing more intense male-male competition. Selection of habitat structure, because it modifies risk of predation, is a major determinant of sociality for ungulates. Likewise, ruggedness and steepness of terrain limit the types of mating systems that can occur because of limitations in group size and cohesiveness, as well as the ability of males to herd even small groups of females effectively. The quality and defensibility of resources affect mating systems, as does the defensibility of females. Population density of females also may be a critical determinant of the types of mating systems that develop. Size of groups likewise constrains the types of mating tactics that males can employ. Our aim was to use those relationships to create a broad conceptual model that predicts how various environmental and social factors interact to structure mating systems in ungulates. This model provides a useful framework for future tests of the roles of both ecological and social conditions in influencing the social systems of ungulates.
有蹄类动物展现出多样的交配系统，范围从一夫一妻制的配对领地到高度多配偶制的求偶场。我们回顾了有蹄类动物的交配系统和行为，并提供了一种新方法，综合阐述相互作用的因素如何塑造这些交配系统。有蹄类动物的物种之间以及物种内部的交配系统存在差异，并且很可能受到捕食风险、资源（食物和配偶）的可获得性、栖息地结构和社会性的影响。由于这些相互作用因素的强度不同，有蹄类动物的交配系统可能是不稳定的。此外，多配偶程度和体型上的两性异形与交配系统的进化有关。然而，雄性间的争斗和父性关怀都无法完全解释有蹄类动物在性体型二态性上的差异，而性体型二态性是理解某些交配系统发展的一个必要组成部分。无论进化途径如何，性别隔离限制了父性关怀，从而使雄性间的竞争更加激烈。栖息地结构的选择，因为它改变了捕食风险，是有蹄类动物社会性的一个主要决定因素。同样，地形的崎岖程度和陡峭程度限制了可能出现的交配系统类型，这是由于群体规模和凝聚力的限制，以及雄性有效聚集甚至一小群雌性的能力受限。资源的质量和可防御性会影响交配系统，雌性的可防御性也是如此。雌性的种群密度也可能是所发展的交配系统类型中的一个关键决定因素。群体规模同样限制了雄性可以采用的交配策略类型。我们的目的是利用这些关系创建一个广泛的概念模型，该模型预测各种环境和社会因素如何相互作用以构建有蹄类动物的交配系统。这个模型为未来测试生态和社会条件在影响有蹄类动物社会系统中的作用提供了一个有用的框架。
