Bénéfices associés à la réutilisation des nids chez l’hirondelle à front blanc (Hirundo pyrrhonota)

Abstract

AbstractTo determine if nest reuse results in energy savings and enhanced nesting success, we compared the energy budgets and nesting success of cliff swallows (Hirundo pyrrhonota) that built new nests (builders) with those that reused old ones (reusers). Energy budgets of the two groups were measured during nest construction and nestling periods using isotopic techniques to estimate their body fat reserves, food consumption and energy expenditures. We found that nest building led to a significant depletion of fat reserves that lasted throughout the incubation and nestling periods. Despite their faster fat depletion, builders showed a nesting success similar to reusers. However, builders suffered a higher nestling mortality than reusers. Moreover, nest reuse was the preferred strategy of cliff swallows. Since bad weather conditions may lead to high building costs and low food availability, we conclude that nest reuse may contribute to an increased breeding success in cliff swallows.