Densidade e uso de habitat de psitacídeos na área de ocorrência histórica da extinta ararinha-azul

Abstract

The body size has been pointed as a potential variable that explains species abundance in different lineages and scales. Such information about the factors influencing both population density and habitat use could aid species conservation programs by choosing potential reintroduction sites, for example. We assessed the relationship between Psittacidae abundance, body size and habitat use in a semi-arid area with conservation interests for reintroduction of extinct Cyanopsitta spixii. Linear transects were plotted to record four parrot species, which density and abundance were estimated by the software DISTANCE 6.0. To verify the relationship between the species and their habitat we used the Soil Ajusted Vegetation Index (SAVI) relative to occurrence points of each species. This points were recorded during sampling in transects. We used ANOVA and Tukey test to identify possible differences on the habitat use between each species, as pointed by SAVI. The most abundant species was Epsittula cactorum with 391 individuals, followed by Primolius maracana (N = 297), Thectocercus acuticaudatus (N = 256) and Amazona aestiva (N = 235). We noticed that the species abundance can be predicted by body mass in the study area. Likewise, species‟ body mass also strongly influences their geographical distribution range (R2 = 0.91 p=0,0049). In contrast, the same does not happen at the local scale (R2 = 0.423 p= 0,0597). We recorded a significant variation on the vegetation index values between the occurrence points of each species (F= 7,9966, p = 0,0049). The values were significantly higher for P. maracana occurrence points, indicating a strong relationship between the species and the arboreal vegetation covering and/or the riparian forest. Our results describe species abundance predictors and suitable habitats of four parrots species as important information to promote conservation actions in the study area, including the reintroduction project of Cyanopsitta spixii.