POPULATION SIZE AND STRUCTURE OF THE THREATENED YELLOW-NAPED PARROT Amazona auropalliata ON THE NICOYA PENINSULA OF COSTA RICA.

MATUZAK, GREG. Amigos de las Aves USA, 22318 Walnut Street, Wildomar, CA 92595, USA; (gmatuzak((AT))hotmail.com).

The Yellow-naped Parrot (Amazona auropalliata) is a threatened species and it is declining throughout its range. On the tip of the Nicoya Peninsula in Costa Rica, a population assessment of this species was conducted through implementing evening roost counts 90 minutes before sunset over an entire year. Population counts ranged from 0 to 300 individuals, with daily count averages ranging between 52 during the nesting/dry season (January to June) to 127 during the wet season (July to November). The roosting site, the Tortuga Islands, located off the coast of Curú National Wildlife Refuge, was also documented to be a nesting site for the species. Family groups (groups of 3 - 4 parrots) were documented during counts and ranged from a low of 1 in May to a high of 19 in October. The young to adult ratio in the population during this time period ranged from a low of 2.1% to a high of 14%. The roosting area being connected to other roost sites and changes in seasonal food availability appear to explain seasonal changes in abundance during roost counts. Regional conservation initiatives for the species should include all nearby roosting sites that exist for this species in the area