Annual variation of adult survival of a south-temperate House Wren population in Argentina

Abstract

Identifying factors affecting the survival of individuals is essential for understanding the evolution of life-history traits and population dynamics. Despite numerous studies on this subject in north-temperate environments, there is a lack of equivalent studies at similar latitudes in the south. Here, we used a 14-year dataset of capture, banding, and resighting to estimate the annual variation in the apparent adult survival probability of a south-temperate population of House Wrens (Troglodytes aedon bonariae). We evaluated temporal variation in survival and the effect of environmental (climatic) and demographic variables (adult abundance, total number of fledglings produced during each breeding season) on survival estimators. We found that the probability of adult survival decreased as the abundance of breeding adults increased. This density-dependent effect could be related to the resident lifestyle of southern House Wrens, which could determine an intense competition for territories and resources that ultimately would affect their survival.