Habitat partitioning and molting site fidelity in Tetrao urogallus cantabricus revealed through stable isotopes analysis

摘要: Sexual dimorphism is often associated with different feeding strategies between sexes because of distinct nutritional demands or intake rates. Capercaillie (Tetrao urogallus) the most sexually dimorphic grouse, thus sexual segregation in resource use likely. This study assessed intrapopulation variation diet related to habitat use, focusing on differential behaviors females and males. We used stable isotopes analyses feathers Cantabrian Capercaillie, a population living at southern edge range purely deciduous forests. analyzed males, sorted them according dominant tree species patch where they were found. Mean isotopic values differed both among forest types. The latter explained variance, suggesting that birds consistently selected certain types molt. showed wider trophic niche seemingly more intra-gender diversity than differences variability support reported previous studies which using micro-habitat diverse treeline areas, while males mainly inner areas Stable isotope analysis proved very useful assess intersexual partitioning rare rugged terrains it logistically difficult rely direct approaches (i.e. observation, capture radio-tracking).