First cavity-nesting records for three Patagonian forest birds

Abstract

We found Austral Thrush (Turdus falcklandii), Patagonian Sierra-finch (Phrygilus patagonicus) and White-crested Elaenia (Elaenia albiceps) nests in tree cavities in the Andean Patagonian forests. These species were not known to nest in cavities. Nests and substrates were described. The three species built cup nests with vegetable matter, similar to those commonly made as open nesters, but placed inside natural cavities in lenga (Nothofagus pumilio) trees. Most of the cavities used were large and trees used as a substrate were also large, with decomposition of the heartwood in all cases. We discuss possible reasons for the absence of previous reports of cavity-nesting for these species, in the light of the nesting habits of related species (i.e., same genera and family).