Osawa Takeshi
National Institute for Agro-Environmental Sciences, 3-1-3, Kannondai, Tsukuba, Ibaraki, 305-8604, Japan,
Environ Manage. 2015 May;55(5):1160-7. doi: 10.1007/s00267-015-0457-5. Epub 2015 Mar 27.
Urbanization is one of the key factors in the population declines of many species. Conversely, some species may favor urbanized areas. The barn swallow Hirundo rustica is well known to breed in urban areas of Japan, and uses both urban and farmland areas as habitat during the breeding season. Specifically, this species often nests on concrete buildings and feeds in surrounding farmland. Therefore, it was hypothesized that H. rustica is not strongly influenced by heavy urbanization and benefits from farmland areas, even if they are not near its nests. In this study, I evaluated the landscape components around H. rustica nests situated on concrete buildings, focusing on both urbanized and farmland areas. In particular, I explored the occurrence of H. rustica nests at train stations in the Kinki region of Japan. Assisted by 124 citizen scientists, I analyzed the landscape components around the train stations at multiple spatial scales. Results showed that the occurrence of H. rustica nests was negatively influenced by both urbanized land area and road density, whereas nest occurrence was positively influenced by farmland area and river density. These results suggest that H. rustica does not prefer urbanized areas overall, but can rather utilize urbanized areas primarily as nesting spots. Therefore, H. rustica cannot breed in heavily urbanized areas without feeding sites such as farmland or riparian areas.
城市化是许多物种数量减少的关键因素之一。相反，一些物种可能偏爱城市化地区。家燕（Hirundo rustica）在日本城市地区繁殖是众所周知的，并且在繁殖季节将城市和农田地区都用作栖息地。具体而言，该物种经常在混凝土建筑物上筑巢，并在周围的农田觅食。因此，有人推测家燕不太受高度城市化的影响，并且即使农田不在其巢穴附近，也能从农田中受益。在本研究中，我评估了位于混凝土建筑物上的家燕巢穴周围的景观组成部分，重点关注城市化地区和农田地区。特别是，我调查了日本近畿地区火车站上家燕巢穴的分布情况。在124位公民科学家的协助下，我在多个空间尺度上分析了火车站周围的景观组成部分。结果表明，城市化土地面积和道路密度对家燕巢穴的分布有负面影响，而农田面积和河流密度对巢穴分布有正面影响。这些结果表明，家燕总体上并不偏爱城市化地区，而是主要将城市化地区用作筑巢地点。因此，如果没有农田或河岸地区等觅食地点，家燕无法在高度城市化地区繁殖。
