The objectives of this study were: (1) to investigate the richness and composition of the Psittacidae in palm swamps; (2) to determine if the sizes of flocks vary seasonally; (3) to compare detectability rates according to species. Psittacid communities were observed from November 2006 to November 2007 in semimonthly visits to the area using fixed-point observation. A total of 1616 individuals from eight species were registered in 199 contacts. The palm swamps were highly similar (H > 0.62), and their diversity was above 1.56. The Yellow-chevroned Parakeet was considered resident in the three palm swamps (Fr > 60 %). The White-eyed Parakeet and Red-bellied Macaw were the most abundant species in the three areas. Most of the species (n = 5) were more abundant in one of the seasons. The most abundant species in the rainy season were the White-eyed Parakeet and Yellow-chevroned Parakeet (42.16 ± 30.77 individuals), whereas in the dry season the most prevalent was the Red-bellied Macaw (68.50 ± 39.35 individuals). The highest detectability rate was for the Yellow-chevroned Parakeet, which demonstrates the inter-species differences and the need to adapt the methods of research, unclear for this family.