Rivkin L Ruth, Johnson Reagan A, Chaves Jaime A, Johnson Marc T J
Department of Ecology and Evolutionary Biology University of Toronto Toronto Ontario Canada.
Department of Biology University of Toronto Mississauga Ontario Canada.
Ecol Evol. 2021 Oct 26;11(22):15754-15765. doi: 10.1002/ece3.8236. eCollection 2021 Nov.
Emerging evidence suggests that humans shape the ecology and evolution of species interactions. Islands are particularly susceptible to anthropogenic disturbance due to the fragility of their ecosystems; however, we know little about the susceptibility of species interactions to urbanization on islands. To address this gap, we studied how the earliest stages of urban development affect interactions between Darwin's finches and its key food resource, , in three towns on the Galápagos Islands. We measured variation in mericarp predation rates, mericarp morphology, and finch community composition using population surveys, experimental manipulations, and finch observations conducted in habitats within and outside of each town. We found that both seed and mericarp removal rates were higher in towns than natural habitats. We also found that selection on mericarp size and defense differed between habitats in the survey and experimental populations and that towns supported smaller and less diverse finch communities than natural habitats. Together, our results suggest that even moderate levels of urbanization can alter ecological interactions between Darwin's finches and . , leading to modified natural selection on . populations. Our study demonstrates that trophic interactions on islands may be susceptible to the anthropogenic disturbance associated with urbanization. Despite containing the highest diversity in the world, studies of urbanization are lacking from the tropics. Our study identified signatures of urbanization on species interactions in a tropical island ecosystem and suggests that changes to the ecology of species interactions has the potential to alter evolution in urban environments.
新出现的证据表明，人类塑造了物种相互作用的生态和进化。由于岛屿生态系统的脆弱性，它们特别容易受到人为干扰；然而，我们对岛屿上物种相互作用对城市化的敏感性知之甚少。为了填补这一空白，我们研究了城市发展的早期阶段如何影响加拉帕戈斯群岛三个城镇中达尔文雀及其主要食物资源之间的相互作用。我们通过在每个城镇内外的栖息地进行种群调查、实验操作和雀类观察，测量了分果捕食率、分果形态和雀类群落组成的变化。我们发现，城镇中的种子和分果去除率均高于自然栖息地。我们还发现，在调查和实验种群中，不同栖息地对分果大小和防御的选择存在差异，并且城镇中支持的雀类群落比自然栖息地更小且多样性更低。总体而言，我们的结果表明，即使是适度的城市化水平也会改变达尔文雀与……之间的生态相互作用，从而导致对……种群的自然选择发生改变。我们的研究表明，岛屿上的营养相互作用可能易受与城市化相关的人为干扰影响。尽管热带地区拥有世界上最高的生物多样性，但对城市化的研究却很匮乏。我们的研究确定了热带岛屿生态系统中城市化对物种相互作用的影响特征，并表明物种相互作用生态的变化有可能改变城市环境中的进化。
