Sunde Peter, Thorup Kasper, Jacobsen Lars B, Rahbek Carsten
Department of Bioscience, Aarhus University, Rønde, Denmark.
Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark.
PLoS One. 2014 Feb 6;9(2):e88221. doi: 10.1371/journal.pone.0088221. eCollection 2014.
Despite the dynamic nature of habitat selection, temporal variation as arising from factors such as weather are rarely quantified in species-habitat relationships. We analysed habitat use and selection (use/availability) of foraging, radio-tagged little owls (Athene noctua), a nocturnal, year-round resident generalist predator, to see how this varied as a function of weather, season and availability. Use of the two most frequently used land cover types, gardens/buildings and cultivated fields varied more than 3-fold as a simple function of season and weather through linear effects of wind and quadratic effects of temperature. Even when controlling for the temporal context, both land cover types were used more evenly than predicted from variation in availability (functional response in habitat selection). Use of two other land cover categories (pastures and moist areas) increased linearly with temperature and was proportional to their availability. The study shows that habitat selection by generalist foragers may be highly dependent on temporal variables such as weather, probably because such foragers switch between weather dependent feeding opportunities offered by different land cover types. An opportunistic foraging strategy in a landscape with erratically appearing feeding opportunities in different land cover types, may possibly also explain decreasing selection of the two most frequently used land cover types with increasing availability.
尽管栖息地选择具有动态性，但由天气等因素引起的时间变化在物种与栖息地关系中很少被量化。我们分析了无线电追踪的食虫小猫头鹰（Athene noctua）的栖息地利用和选择（利用/可利用性）情况，小猫头鹰是一种夜行性、全年栖息的广食性捕食者，目的是了解其如何随天气、季节和可利用性而变化。通过风的线性效应和温度的二次效应，作为季节和天气的简单函数，两种最常用的土地覆盖类型（花园/建筑物和耕地）的利用变化超过3倍。即使在控制时间背景的情况下，两种土地覆盖类型的利用都比根据可利用性变化预测的更为均匀（栖息地选择中的功能反应）。其他两种土地覆盖类别（牧场和潮湿地区）的利用随温度线性增加且与它们的可利用性成正比。该研究表明，广食性觅食者的栖息地选择可能高度依赖于天气等时间变量，这可能是因为此类觅食者会在不同土地覆盖类型提供的依赖天气的觅食机会之间切换。在不同土地覆盖类型中觅食机会不规则出现的景观中，机会主义觅食策略可能也解释了随着可利用性增加，两种最常用土地覆盖类型的选择减少的现象。
