Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, 37996, USA.
Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, 70118, USA.
Microb Ecol. 2021 Jan;81(1):253-266. doi: 10.1007/s00248-020-01569-8. Epub 2020 Aug 16.
Habitats are changing rapidly around the globe and urbanization is one of the primary drivers. Urbanization changes food availability, environmental stressors, and the prevalence of disease for many species. These changes can lead to divergence in phenotypic traits, including behavioral, physiological, and morphological features between urban and rural populations. Recent research highlights that urbanization is also changing the gut microbial communities found in a diverse group of host species. These changes have not been uniform, leaving uncertainty as to how urban habitats are shaping gut microbial communities. To better understand these effects, we investigated the gut bacterial communities of White-Crowned Sparrow (Zonotrichia leucophrys) populations along an urbanization gradient in the San Francisco Bay area. We examined how gut bacterial communities vary with the local environment and host morphological characteristics. We found direct effects of environmental factors, including urban noise levels and territory land cover, as well as indirect effects through body size and condition, on alpha and beta diversity of gut microbial communities. We also found that urban and rural birds' microbiomes differed in which variables predicted their diversity, with urban communities driven by host morphology, and rural communities driven by environmental factors. Elucidating these effects provides a better understanding of how urbanization affects wild avian physiology.
全球的栖息地正在迅速变化，城市化是主要驱动力之一。城市化改变了许多物种的食物供应、环境压力和疾病的流行程度。这些变化可能导致表型特征的差异，包括城市和农村种群之间的行为、生理和形态特征。最近的研究强调，城市化也在改变多种宿主物种中发现的肠道微生物群落。这些变化并不均匀，因此不确定城市栖息地是如何塑造肠道微生物群落的。为了更好地理解这些影响，我们沿着旧金山湾区的城市化梯度调查了白头鹎（Zonotrichia leucophrys）种群的肠道细菌群落。我们研究了肠道细菌群落如何随当地环境和宿主形态特征而变化。我们发现环境因素（包括城市噪音水平和领地土地覆盖）以及通过体型和状况的间接影响，对肠道微生物群落的 alpha 和 beta 多样性有直接影响。我们还发现，城市和农村鸟类的微生物组在哪些变量可以预测它们的多样性方面存在差异，城市群落受宿主形态驱动，而农村群落受环境因素驱动。阐明这些影响可以更好地了解城市化如何影响野生鸟类的生理学。
