Understanding how biodiversity responds to urbanization is challenging, due in part to the single‐city focus of most urban ecological research. Here, we delineate continent‐scale patterns in urban species assemblages by leveraging data from a multi‐city camera trap survey and quantify how differences in greenspace availability and average housing density among 10 North American cities relate to the distribution of eight widespread North American mammals. To do so, we deployed camera traps at 569 sites across these ten cities between 18 June and 14 August. Most data came from 2017, though some cities contributed 2016 or 2018 data if it was available. We found that the magnitude and direction of most species' responses to urbanization within a city were associated with landscape‐scale differences among cities. For example, eastern gray squirrel (Sciurus carolinensis), fox squirrel (Sciurus niger), and red fox (Vulpes vulpes) responses to urbanization changed from negative to positive once the proportion of green space within a city was >~20%. Likewise, raccoon (Procyon lotor) and Virginia opossum (Didelphis virginiana) responses to urbanization changed from positive to negative once the average housing density of a city exceeded about 700 housing units/km². We also found that local species richness within cities consistently declined with urbanization in only the more densely developed cities (>~700 housing units/km²). Given our results, it may therefore be possible to design cities to better support biodiversity and reduce the negative influence of urbanization on wildlife by, for example, increasing the amount of green space within a city. Additionally, it may be most important for densely populated cities to find innovative solutions to bolster wildlife resilience because they were the most likely to observe diversity losses of common urban species.

中文翻译：

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城市之间的景观尺度差异改变了常见物种对城市化的反应

部分由于大多数城市生态研究关注的是单一城市，因此了解生物多样性如何应对城市化具有挑战性。在这里，我们通过利用来自多城市相机诱集调查的数据来描述城市物种集合中的大洲尺度模式，并量化了北美10个城市之间绿地可用性和平均住房密度的差异如何与8种北美哺乳动物的分布有关。为此，我们于6月18日至8月14日在这10个城市的569个地点部署了相机陷阱。大多数数据来自2017年，尽管有些城市提供了2016年或2018年的数据。我们发现，城市中大多数物种对城市化的反应的程度和方向与城市之间的景观尺度差异有关。例如，东部灰松鼠（一旦城市中的绿地比例超过20％，则对城市化的反应就由松鼠carolinensis，狐狸松鼠（Sciurus niger）和赤狐（Vulpes vulpes）的响应从负变为正。同样，一旦城市的平均住房密度超过700个住房单位/ km ²，浣熊（Procyon lotor）和弗吉尼亚负鼠（Didelphis virginiana）对城市化的反应就会从积极变为消极。我们还发现，只有城市化程度更高的城市（>〜700个住房单位/ km ^2），城市中的本地物种丰富度才随着城市化而持续下降。）。根据我们的结果，因此有可能设计一些城市来更好地支持生物多样性，并通过例如增加城市内的绿色空间来减少城市化对野生动植物的负面影响。此外，对于人口稠密的城市而言，找到创新的解决方案以增强野生动植物的适应力可能是最重要的，因为它们最有可能观察到常见城市物种的多样性丧失。