Rethinking trophic niches: Speed and body mass colimit prey space of mammalian predators
Rethinking trophic niches: Speed and body mass colimit prey space of mammalian predators
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DOI：
10.1002/ece3.6411
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发表时间：
2020-06-28
影响因子：
2.6
通讯作者：
Brose, Ulrich
中科院分区：
文献类型：
--
作者：
Hirt, Myriam R.;Tucker, Marlee;Brose, Ulrich
现实的捕食者营养生态位的特点往往是沿着一维范围内的捕食者-猎物的体重比。这个猎物的范围是由一个“能量限制”和“制服限制”对小型和大型猎物，分别。除了这些身体质量比，最大速度是大多数捕食者与猎物相互作用的另一个关键组成部分。在这里，我们通过引入一个驼峰形的速度-身体质量关系，将一维食饵范围的概念扩展到二维食饵空间。这种新的“速度限制”还限制了捕食者对快速猎物的营养生态位。为了测试这个概念的二维猎物空间不同的狩猎策略（追求，组，伏击捕食），我们合成了63陆生哺乳动物捕食者-猎物的相互作用，他们的身体质量和最大速度的数据。我们发现，追求捕食者狩猎较小和较慢的猎物，而群体猎人专注于较大但大多较慢的猎物和捕食者更灵活。群体狩猎者和捕食者已经进化出不同的策略来占据相似的营养生态位，避免与追捕捕食者竞争。此外，我们的概念表明，这些狩猎策略沿着身体质量轴充满活力的最佳，从而提供了机械解释为什么没有小团体猎人（称为“微型狮子”）或大型食肉动物（称为“巨型猎豹”）。我们的研究结果表明，通过增加新的速度维度，推进猎物范围到猎物空间的概念，将促进对捕食者营养生态位的新的机械理解，并提高我们对捕食者-猎物相互作用，食物网结构和生态系统功能的预测。
Realized trophic niches of predators are often characterized along a one-dimensional range in predator-prey body mass ratios. This prey range is constrained by an "energy limit" and a "subdue limit" toward small and large prey, respectively. Besides these body mass ratios, maximum speed is an additional key component in most predator-prey interactions. Here, we extend the concept of a one-dimensional preyrangeto a two-dimensional preyspaceby incorporating a hump-shaped speed-body mass relation. This new "speed limit" additionally constrains trophic niches of predators toward fast prey. To test this concept of two-dimensional prey spaces for different hunting strategies (pursuit, group, and ambush predation), we synthesized data on 63 terrestrial mammalian predator-prey interactions, their body masses, and maximum speeds. We found that pursuit predators hunt smaller and slower prey, whereas group hunters focus on larger but mostly slower prey and ambushers are more flexible. Group hunters and ambushers have evolved different strategies to occupy a similar trophic niche that avoids competition with pursuit predators. Moreover, our concept suggests energetic optima of these hunting strategies along a body mass axis and thereby provides mechanistic explanations for why there are no small group hunters (referred to as "micro-lions") or mega-carnivores (referred to as "mega-cheetahs"). Our results demonstrate that advancing the concept of prey ranges to prey spaces by adding the new dimension of speed will foster a new and mechanistic understanding of predator trophic niches and improve our predictions of predator-prey interactions, food web structure, and ecosystem functions.