Adjustments in habitat selection to changing availability induce fitness costs for a threatened ungulate

1. Functional responses in habitat selection occur when individuals adjust their selection of habitat features as a function of the availability of those features. Functional responses in habitat selection are generally assumed to be fitness-rewarding tactics and are used to guide conservation actions. Fitness consequences of functional responses, however, have rarely been evaluated. 2. Eighty-three caribou were followed with GPS collars to establish the link between functional responses in habitat selection and adult female survival, a strong fitness correlate for caribou. We measured how caribou avoidance of mixed/deciduous stands and 6–20-year-old clearcuts varied with the proportion of 6–20-year-old clearcuts within their 100% minimal convex polygon (MCP), and if these functional responses were linked to survival. Mixed/deciduous stands and 6–20-year-old clearcuts are risky for caribou because they are selected by moose, thereby attracting wolves and increasing predation risk for ca...

1. 生境选择中的功能响应（functional responses）是指个体依据生境特征的可获得程度，调整其对该类生境特征的选择行为。学界通常认为生境选择的功能响应是提升适合度的适应性策略，并将其用于指导保护实践。然而，功能响应所带来的适合度后果却极少得到评估。2. 本研究通过GPS项圈追踪了83头驯鹿，以建立生境选择的功能响应与成年雌性存活率——驯鹿适合度的重要关联指标——之间的关联。我们量化了驯鹿对混交/落叶林分以及6~20年生皆伐迹地的回避行为随其100%最小凸多边形（minimal convex polygon, MCP）内6~20年生皆伐迹地占比的变化规律，并探究此类功能响应是否与存活率相关。混交/落叶林分与6~20年生皆伐迹地对驯鹿而言属于高风险生境，因为驼鹿会偏好利用此类生境，进而吸引狼聚集，提升驯鹿的捕食风险……