Courtois Ève, Garant Dany, Pelletier Fanie, Bélisle Marc
Département de Biologie Université de Sherbrooke Sherbrooke Quebec Canada.
Ecol Evol. 2021 Nov 9;11(22):16296-16313. doi: 10.1002/ece3.8323. eCollection 2021 Nov.
Animals are expected to select a breeding habitat using cues that should reflect, directly or not, the fitness outcome of the different habitat options. However, human-induced environmental changes can alter the relationships between habitat characteristics and their fitness consequences, leading to maladaptive habitat choices. The most severe case of such nonideal habitat selection is the ecological trap, which occurs when individuals prefer to settle in poor-quality habitats while better ones are available. Here, we studied the adaptiveness of nest box selection in a tree swallow () population breeding over a 10-year period in a network of 400 nest boxes distributed along a gradient of agricultural intensification in southern Québec, Canada. We first examined the effects of multiple environmental and social habitat characteristics on nest box preference to identify potential settlement cues. We then assessed the links between those cues and habitat quality as defined by the reproductive performance of individuals that settled early or late in nest boxes. We found that tree swallows preferred nesting in open habitats with high cover of perennial forage crops, high spring insect biomass, and high density of house sparrows (), their main competitors for nest sites. They also preferred nesting where the density of breeders and their mean number of fledglings during the previous year were high. However, we detected mismatches between preference and habitat quality for several environmental variables. The density of competitors and conspecific social information showed severe mismatches, as their relationships to preference and breeding success went in opposite direction under certain circumstances. Spring food availability and agricultural landscape context, while related to preferences, were not related to breeding success. Overall, our study emphasizes the complexity of habitat selection behavior and provides evidence that multiple mechanisms may potentially lead to an ecological trap in farmlands.
动物有望利用一些线索来选择繁殖栖息地，这些线索应直接或间接地反映不同栖息地选择的适合度结果。然而，人为引起的环境变化会改变栖息地特征与其适合度后果之间的关系，导致不适应的栖息地选择。这种非理想栖息地选择的最严重情况是生态陷阱，即当个体更倾向于在质量较差的栖息地定居，而有更好的栖息地可供选择时就会发生。在此，我们研究了在加拿大魁北克省南部沿农业集约化梯度分布的400个巢箱网络中，树燕（）种群在10年繁殖期内巢箱选择的适应性。我们首先研究了多种环境和社会栖息地特征对巢箱偏好的影响，以确定潜在的定居线索。然后，我们评估了这些线索与栖息地质量之间的联系，栖息地质量由在巢箱中早定居或晚定居个体的繁殖表现来定义。我们发现，树燕更喜欢在多年生饲料作物覆盖率高、春季昆虫生物量高以及家麻雀（）密度高的开阔栖息地筑巢，家麻雀是它们筑巢地点的主要竞争者。它们也更喜欢在繁殖者密度高以及前一年雏鸟平均数量多的地方筑巢。然而，我们发现几个环境变量在偏好和栖息地质量之间存在不匹配。竞争者密度和同种社会信息显示出严重的不匹配，因为在某些情况下，它们与偏好和繁殖成功率的关系呈相反方向。春季食物可利用性和农业景观背景虽然与偏好有关，但与繁殖成功率无关。总体而言，我们的研究强调了栖息地选择行为的复杂性，并提供了证据表明多种机制可能会在农田中导致生态陷阱。
