具有生态相似性的密切相关的物种经常积极竞争一个共同的,资源有限。这种竞争通常是不对称的,导致一个物种在行为上占主导地位。行为优势性状和替代策略之间的权衡可以导致优势种和从属种之间不同的资源获取方法,对资源分配和社区结构产生了重要影响。体型是通常被认为决定行为优势的关键特征。优先效果(即,哪些物种首先到达资源),然而,还可以确定互动的结果,除了大小之外,物种特定的特征也可以在侵略性竞赛中提供优势(例如,武器)。这里,我们在这三个身体大小的替代假设中进行测试,优先效果,和物种身份决定了两种掩埋甲虫之间竞争性相互作用的结果,鸟颈微带和猪笼草。栖息地和季节性都重叠,并且在小型脊椎动物腐肉的共享繁殖资源上表现出激烈的竞争。在审判中,我们通过将一个car体和每个物种的一个甲虫放在一个容器中并观察13h试验(n=17试验)的相互作用,模拟了甲虫在自然界中发现car体时会发生什么。我们记录并分类了甲虫之间的相互作用以及每个人与car体(关键资源)接触的持续时间,以确定哪个假设可以预测试验结果。体型是我们唯一的重要预测指标;最大的物种赢得了最积极的相互作用,并花了更多的时间与car体接触。我们的结果提供了对N.orbicollis和N.pustulatus的生态和资源分配模式的见解,后者在当地的Nicrophorus中是独一无二的,因为它是树冠专家。在所有Nicrophorus中,pustulatus在使用蛇卵方面也是独一无二的,除了其他腐肉,作为育种资源。我们的结果强调了体型和相关权衡在生态学中的重要性,并暗示了与其他共存物种和群落的相似之处。
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 (i.e., 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 (e.g., 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, Nicrophorus orbicollis and N. pustulatus. 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 (n = 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 N. orbicollis and N. pustulatus, the latter of which is unique among local Nicrophorus for being a canopy specialist. N. pustulatus is also unique among all Nicrophorus 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.