Data from: Are house sparrow populations limited by the lack of cavities in urbanized landscapes? an experimental test.

Current urban policies are associated with deep changes in urban
structures, which may impoverish urban biodiversity. A major concern is
the disappearance of nesting sites for wild vertebrate species living in
urban areas. New urban structures without any cracks or cavities may
especially preclude cavity nesters from breeding in cities and they may
cause population declines. In that context, we experimentally investigated
this question in an urban exploiter bird species (the house sparrow,
Passer domesticus), which is dramatically declining in most European
cities. To test if the lack of cavities is limiting house sparrow
populations in urban areas, we equipped 11 sites along an urbanization
gradient with nest boxes and we then evaluated the rate of occupancy of
these nest-boxes. This urbanization gradient was characterized by very
rural places (isolated farms) and moderately urbanized areas (town of
medium size, i.e. 60 000 inhabitants). Surprisingly, rural nest boxes were
more occupied than urban ones, suggesting that cavity availability is
probably more constraining in rural areas relative to urban ones.
Therefore, our study suggests that urban house sparrow populations are
probably not constrained by a lack of nesting sites in medium size cities
with urban designs similar to our city of interest (Niort, Western
France). This hypothesis definitely needs now to be tested in further
urban landscapes (e.g. large cities and urban landscapes with other
architecture and management policies).

当前城市政策与城市结构的深刻变革紧密相关，而此类变革或会削弱城市生物多样性。当前学界的一大核心关切为：城市区域内野生脊椎动物的筑巢位点正不断消失。无任何缝隙或天然洞穴的新型城市建筑结构，尤其会阻碍洞巢类物种在城市中繁衍，进而可能引发种群数量下降。在此背景下，我们针对一种在多数欧洲城市中种群数量急剧下降的城市利用型鸟类——家雀（Passer domesticus），通过实验对这一问题展开研究。为验证洞穴匮乏是否会限制城市家雀的种群规模，我们在沿城市化梯度设置的11个样地中安装了巢箱（nest boxes），并对这些巢箱的占用率进行了评估。该城市化梯度涵盖了极乡村化区域（孤立农场）与中度城市化区域（中等规模城镇，即人口约6万的城镇）。令人意外的是，乡村样地的巢箱占用率高于城市样地，这表明相较于城市区域，乡村地区的洞穴可获得性对鸟类的限制作用可能更强。因此，本研究表明，在与本次研究区域（法国西部尼奥尔特市）城市设计相似的中等规模城市中，城市家雀种群大概率不会受到筑巢位点匮乏的限制。该假说仍需在更多城市景观（例如大城市以及采用其他建筑与管理政策的城市区域）中进一步验证。

搜集汇总

背景与挑战

背景概述

该数据集研究了城市家麻雀种群数量是否受巢穴缺乏限制的问题，通过实验发现乡村巢箱占用率高于城市，表明城市家麻雀种群可能不受巢穴缺乏的限制。数据集包含城市化评分、巢箱占用率和繁殖率等关键信息。