Ecological Notes on the Green Parakeet of Isla Socorro, Mexico

Abstract

Key words: Green Parakeet; Aratinga holochlora brevipes; status: flock size: diet; Isla Socorro, Mexico. The Green Parakeet of Isla Socorro (Aratinga holochlo- ru brevipes Lawrence) is an endemic subspecies (Gray- son 1870-1871, Anthony 1898, McLellan 1926, Villa 1960, Jehl and Parkes 1982). However, no quantitative information exists on the abundance of the species on the island, and very little is known of its feeding habits, nesting and flocking behavior. Previous studies of the endemic birds of Socorro Island have noted the need for additional information on the status of the species due to the serious environmental problems the island has faced since the last centurv (Jehl and Parkes 1982. 1983). Thus, information regarding their status could permit evaluation of population changes. This note presents information on the abundance and some as- pects of the ecology of the Socorro Green Parakeet. Study area and methods. Socorro Island is located approximately 450 km to the south southwest of the southern tip of Baja California, Mexico (Fig. 1). De- scriptions of the island may be found in Levin and Moran (1989) and Brattstrom (1990). Six plant asso- ciations have been recognized on the island (Miranda 1960, Levin and Moran 1989, Leon de la Luz et al. 1990). The mixed scrub, dominated by Dodonaeu vis- cose and Pteridium caudutum (O-700 m) and the forest, dominated by Bumelia socorrensis, Ilex socorrensis, Guettarda insularis, Psidium socorrense (350-850 m) and Ficus cotinzfiha (100-300 m) cover most of the area on the island.