Abundance and distribution of parrots along the elevational gradient of Calilegua National Park, Argentina

In February 2001, we recorded six parrot species and detected differences in their distribution patterns and abundances along an elevational gradient in the montane forests of the Calilegua National Park in northwestern Argentina. The study area was divided into four forest types (from low to high altitude: Piedmont, transition to montane, montane, and transition to cloud). The transition to cloud forest had the lowest number of species. Yellow-collared Macaws (Propyrrhura auricollis), Scaly-headed Parrots (Pionus maximiliani) and Green-cheeked Parakeets (Pyrrhura molinae) occurred in three forest types at the lower end of the elevational gradient. White-eyed Parakeets (Aratinga leucophthalma) occupied Piedmont and transition to montane, whereas Mitred Parakeets (A. mitrata) occupied montane and transition to cloud forest, showing a replacement of species of the genus Aratinga in different forest types. Tucuman Parrots (Amazona tucumana) were found only in transition to cloud forest. Five species were significantly more abundant in a particular forest type: White-eyed Parakeet in Piedmont, Mitred Parakeet in transition to cloud, Scaly-headed Parrot in transition to montane, Green-cheeked Parakeet in Piedmont, and Tucuman Parrot in transition to cloud. However, Yellow-collared Macaws did not show significant abundance difference among the three forest types where it was detected. Most observations of White-eyed Parakeets and Tucuman Parrots were in pairs, whereas Mitred Parakeets, Yellow-collared Macaws, Scaly-headed Parrots, and Green-cheeked Parakeets were in groups >= 4 individuals. This study highlights the importance of conserving the complete elevational gradient. Accepted 1 October 2004.