Parrot Nesting in Southeastern Peru: Seasonal Patterns and Keystone Trees

—Parrots that inhabit tropical lowland forests are difficult to study, are poorly known, and little information is available on their nesting habits, making analysis of community-wide nesting patterns difficult. I present nesting records for 15 species of psittacids that co-occur in southeastern Peru. The psittacid breeding season in this area lasted from June to April, with smaller species nesting earlier than larger species. Why smaller species bred earlier is uncertain, though it may be related to interspecific competition for nest sites or variations in food availability. This study identified two keystone plant resources used by nesting parrots: Dipteryx micrantha (Fabaceae) and Mauritia flexuosa (Arecaceae). Local threats to these plant species are discussed. Received 25 August 2003, accepted 14 April 2005. Nesting is a critically important stage in the natural history of all bird species. Reproductive failure has caused numerous conservation crises, so knowledge of nesting habits is critical (Ratcliffe 1967, Herkert et al. 2003). The nesting ecology of many tropical species remains poorly documented, especially for canopy nesters in dense, lowland tropical forests. The family Psittacidae is the most endangered large avian family in the world, making its study a conservation priority (Bennett and Owens 1997, Collar 1997). Most of our knowledge of parrot nesting comes from anecdotal accounts by early collectors (Huber 1933), regional avifaunal compendia (Cherrie 1916, Havershmidt 1968), detailed studies of individual taxa (reviewed in Masello and Quillfeldt 2002), and the monumental compendium of Forshaw (1989). New World parrot diversity is highest in the western Amazon Basin, where communities commonly include more than 15 species (Roth 1984, Montambault 2002). This diversity peaks in southeastern Peru, where 18 to 20 species have been reported at various sites (Terborgh et al. 1984, Foster et al. 1994). However, the nesting season for all but five species in the region remains undocumented, making community-level analyses impossible. Here, I report on the nesting season for 15 species of sympatric parrots inhabiting lowlands of the western Amazon Basin in southeastern Peru. Land clearing and pressures on global forest resources are constantly increasing. As for1 Duke Univ., Dept. of Biology, Durham, NC 27708, USA; e-mail: [email protected] est areas shrink, conservationists must prioritize their conservation efforts. Large, old trees and the cavities they contain are vital for the persistence of many cavity-nesting birds (Mawson and Long 1994, Poulsen 2002). However, cavity nesters usually do not use trees in proportion to their abundance, suggesting that some tree species are more important than others to these birds (Martin and Eadie 1999, Monterrubio and Enkerlin 2004). In this study, I compiled nesting records for 15 species to determine which trees were most important to the nesting parrot community in southeastern Peru.