Department of Biology, Queen's University, Kingston, Ontario, Canada.
PeerJ. 2023 Nov 23;11:e16090. doi: 10.7717/peerj.16090. eCollection 2023.
Closely related species with ecological similarity often aggressively compete for a common, limited resource. This competition is usually asymmetric and results in one species being behaviorally dominant over the other. Trade-offs between traits for behavioral dominance and alternative strategies can result in different methods of resource acquisition between the dominant and subordinate species, with important consequences for resource partitioning and community structure. Body size is a key trait thought to commonly determine behavioral dominance. Priority effects (., which species arrives at the resource first), however, can also determine the outcome of interactions, as can species-specific traits besides size that give an advantage in aggressive contests (., weapons). Here, we test among these three alternative hypotheses of body size, priority effects, and species identity for what determines the outcome of competitive interactions among two species of burying beetles, and . Both overlap in habitat and seasonality and exhibit aggressive competition over a shared breeding resource of small vertebrate carrion. In trials, we simulated what would happen upon the beetles' discovery of a carcass in nature by placing a carcass and one beetle of each species in a container and observing interactions over 13 h trials ( = 17 trials). We recorded and categorized interactions between beetles and the duration each individual spent in contact with the carcass (the key resource) to determine which hypothesis predicted trial outcomes. Body size was our only significant predictor; the largest species won most aggressive interactions and spent more time in contact with the carcass. Our results offer insight into the ecology and patterns of resource partitioning of and , the latter of which is unique among local for being a canopy specialist. is also unique among all in using snake eggs, in addition to other carrion, as a breeding resource. Our results highlight the importance of body size and related trade-offs in ecology and suggest parallels with other coexisting species and communities.
生态相似的密切相关物种通常会为争夺共同的、有限的资源而激烈竞争。这种竞争通常是不对称的，导致一个物种在行为上对另一个物种具有优势。行为优势和替代策略之间的权衡取舍可能导致优势种和从属种在获取资源方面采用不同的方法，这对资源分配和群落结构有重要影响。体型是一个关键特征，通常被认为决定着行为优势。然而，优先效应（即哪种物种先到达资源）也可以决定相互作用的结果，除了体型之外，还有一些物种特有的特征在攻击性竞争中具有优势（例如武器）。在这里，我们测试了体型、优先效应和物种身份这三个替代假设，以确定两种埋葬甲虫（ 和 ）之间竞争相互作用的结果由什么决定。这两个物种在栖息地和季节性上重叠，并对小型脊椎动物尸体这一共同繁殖资源表现出强烈的竞争。在试验中，我们通过将一具尸体和每只甲虫放入一个容器中，模拟了甲虫在自然界中发现尸体时会发生的情况，并在 13 小时的试验中观察相互作用（ = 17 次试验）。我们记录和分类了甲虫之间的相互作用，并记录了每个个体与尸体（关键资源）接触的持续时间，以确定哪个假设预测了试验结果。体型是我们唯一的显著预测因子；最大的物种在大多数攻击性相互作用中获胜，并与尸体接触的时间更长。我们的研究结果为 和 的生态学和资源分配模式提供了深入了解，其中后者是当地唯一一种树冠专家。 也是所有 中唯一一种除了其他腐肉之外还将蛇卵用作繁殖资源的物种。我们的研究结果强调了体型和相关权衡在生态学中的重要性，并表明与其他共存物种和群落存在相似之处。
