Kozlovsky Dovid Y, Weissgerber Emily A, Pravosudov Vladimir V
Department of Biology, Evolution and Conservation Biology Doctoral Program, University of Nevada, Reno, NV, USA
Ecology, Evolution and Conservation Biology Doctoral Program, University of Nevada, Reno, NV, USA.
Proc Biol Sci. 2017 May 31;284(1855). doi: 10.1098/rspb.2016.2613.
Anthropogenic environments are a dominant feature of the modern world; therefore, understanding which traits allow animals to succeed in these urban environments is especially important. Overall, generalist species are thought to be most successful in urban environments, with better general cognition and less neophobia as suggested critical traits. It is less clear, however, which traits would be favoured in urban environments in highly specialized species. Here, we compared highly specialized food-caching mountain chickadees living in an urban environment (Reno, NV, USA) with those living in their natural environment to investigate what makes this species successful in the city. Using a 'common garden' paradigm, we found that urban mountain chickadees tended to explore a novel environment faster and moved more frequently, were better at novel problem-solving, had better long-term spatial memory retention and had a larger telencephalon volume compared with forest chickadees. There were no significant differences between urban and forest chickadees in neophobia, food-caching rates, spatial memory acquisition, hippocampus volume, or the total number of hippocampal neurons. Our results partially support the idea that some traits associated with behavioural flexibility and innovation are associated with successful establishment in urban environments, but differences in long-term spatial memory retention suggest that even this trait specialized for food-caching may be advantageous. Our results highlight the importance of environmental context, species biology, and temporal aspects of invasion in understanding how urban environments are associated with behavioural and cognitive phenotypes and suggest that there is likely no one suite of traits that makes urban animals successful.
人为环境是现代世界的一个主要特征；因此，了解哪些特征能让动物在这些城市环境中取得成功尤为重要。总体而言，广适性物种被认为在城市环境中最为成功，具有更好的一般认知能力和较少的新事物恐惧被认为是关键特征。然而，对于高度特化的物种来说，哪些特征在城市环境中会更受青睐还不太清楚。在这里，我们将生活在美国内华达州里诺市城市环境中的高度特化的食物贮藏型黑顶山雀与生活在其自然环境中的同类进行比较，以探究是什么让这个物种在城市中取得成功。使用“共同花园”范式，我们发现与森林中的黑顶山雀相比，城市黑顶山雀倾向于更快地探索新环境且移动更频繁，在解决新问题方面表现更好，具有更好的长期空间记忆保持能力，并且端脑体积更大。城市黑顶山雀和森林黑顶山雀在新事物恐惧、食物贮藏率、空间记忆获取、海马体体积或海马体神经元总数方面没有显著差异。我们的结果部分支持了这样一种观点，即一些与行为灵活性和创新相关的特征与在城市环境中的成功定居有关，但长期空间记忆保持能力的差异表明，即使是这种专门用于食物贮藏的特征也可能具有优势。我们的结果强调了环境背景、物种生物学以及入侵的时间因素在理解城市环境如何与行为和认知表型相关联方面的重要性，并表明可能不存在一套能让城市动物成功的单一特征组合。
