Several cavity-nesting birds fight for a single tree hollow in an Atlantic Forest fragment: consequence of increasing nest-site limitation?

Abstract

Most remnants of Atlantic Forests are found as small and isolated forest fragments. Forest fragmentation and edge effects often lead to structural changes in vegetation that may affect the availability of tree cavities for birds that rely on hollows for reproduction. Here I describe an unusual dispute for a cavity among birds (at least six Primolius maracana, two Pionus maximiliani  (Psittacidae) and two Pteroglossus aracari (Ramphastidae)) in the Estação Ecológica dos Catetetus, southeast Brazil. Consequences of Atlantic Forest fragmentation, together with an increase in abundance of cavity users such as Opossums (Didelphis spp.) and exotic Honey Bees (Apis mellifera) might be decreasing the already small availability of cavities for medium- and large-sized cavity-nesting birds. The conservation of large hardwood trees is probably critical for the persistence of cavity-nesting birds in fragmented Atlantic Forest landscapes. Supply of nest boxes and control of Honey Bees may also be considered.