Applied Wildlife Ecology Lab, Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA.
J Anim Ecol. 2020 Aug;89(8):1952-1960. doi: 10.1111/1365-2656.13266. Epub 2020 Jun 20.
Generalist species, by definition, exhibit variation in niche attributes that promote survival in changing environments. Increasingly, phenotypes previously associated with a species, particularly those with wide or expanding ranges, are dissolving and compelling greater emphasis on population-level characteristics. In the present study, we assessed spatial variation in diet characteristics, gut microbiome and associations between these two ecological traits across populations of coyotes Canis latrans. We highlight the influence of the carnivore community in shaping these relationships, as the coyote varied from being an apex predator to a subordinate, mesopredator across sampled populations. We implemented a scat survey across three distinct coyote populations in Michigan, USA. We used carbon (δ C) and nitrogen (δ N) isotopic values to reflect consumption patterns and trophic level, respectively. Corresponding samples were also paired with 16S rRNA sequencing to describe the microbial community and correlate with isotopic values. Although consumption patterns were comparable, we found spatial variation in trophic level among coyote populations. Specifically, δ N was highest where coyotes were the apex predator and lowest where coyotes co-occurred with grey wolves Canis lupus. The gut microbial community exhibited marked spatial variation across populations with the lowest operational taxonomic units diversity found where coyotes occurred at their lowest trophic level. Bacteriodes and Fusobacterium dominated the microbiome and were positively correlated across all populations. We found no correlation between δ C and microbial community attributes. However, positive associations between δ N and specific microbial genera increased as coyotes ascended trophic levels. Coyotes provide a model for exploring implications of niche plasticity because they are a highly adaptable, wide-ranging omnivore. As coyotes continue to vary in trophic position and expand their geographic range, we might expect increased divergence within their microbial community, changes in physiology and alterations in behaviour.
广义种，根据定义，表现出生态位属性的变化，这些变化促进了在变化环境中的生存。越来越多的先前与一个物种相关的表型，特别是那些具有广泛或扩展范围的表型，正在消失，并迫使人们更加关注种群水平的特征。在本研究中，我们评估了饮食特征、肠道微生物组在不同种群间的空间变化，并研究了这两个生态特征之间的关联。我们强调了食肉动物群落对这些关系的影响，因为在被采样的种群中，郊狼（Canis latrans）的角色从顶级捕食者转变为从属的中型捕食者。我们在美国密歇根州的三个不同的郊狼种群中进行了粪便调查。我们使用碳（δ C）和氮（δ N）同位素值来分别反映消费模式和营养水平。相应的样本也与 16S rRNA 测序配对，以描述微生物群落，并与同位素值相关联。尽管消费模式相似，但我们发现不同郊狼种群之间的营养水平存在空间差异。具体来说，当郊狼是顶级捕食者时，δ N 最高，而当郊狼与灰狼（Canis lupus）共存时，δ N 最低。肠道微生物群落在种群间表现出明显的空间差异，其中郊狼处于最低营养水平的地方，操作分类单元多样性最低。拟杆菌属和梭菌属在整个种群中占主导地位，并且在所有种群中都呈正相关。我们没有发现 δ C 和微生物群落特征之间的相关性。然而，随着郊狼在营养水平上的上升，δ N 与特定微生物属之间的正相关关系增加。郊狼为探索生态位可塑性的影响提供了一个模型，因为它们是一种适应性强、分布广泛的杂食动物。随着郊狼在营养位置上的变化和地理范围的扩大，我们可能会期望它们的微生物群落内部出现更多的分歧、生理变化和行为改变。
