Atributos da paisagem e espécies congêneres alóctones influenciam a ocorrência de Callithrix aurita em remanescentes florestais do Brasil

Abstract

Callithrix aurita is one of the world’s 25 most endangered primates, mostly due to fragmentation, habitat loss, and congeners allochthonous species introduction, and consequent competition and hybridization. It is a critical situation, once the species is endemic to Atlantic Forest, a fragmented biome, which has only 12.4% of its original area. As an essentially arboreal species, its occurrence is expected to be linked to landscape characteristics. It was evaluated if area size, minimal distance to allochthonous species, altitude, connectivity, and percentage of types of the matrix influenced the species occurrence in its distribution area. Using occurrence data from two data papers, 46 sampling sites (23 with confirmed occurrence of C. aurita and 23 control, without the confirmed occurrence of C. aurita) were established. A set of balanced models were created with every possible additive combination with up to four variables per model, which allowed the interpretation of the cumulative AICc weight (w+) of each predictor variable of interest, considering that variables with w+ ≥ 0.50 were considered as the determinants for influencing the occurrence of C. aurita. Using this strategy, 1093 models were built, with the smallest distance to C. jacchus (w+ = 0.94) and the matrix of non-vegetated areas (w+ = 0.59) negatively correlated with the occurrence of C. aurita. While the percentage of mosaic matrix of agriculture and pasture (w+ = 0.61) and the percentage of matrix of savanna formation (w+ = 0.59) correlated positively with the occurrence of the species. From these results we can infer that C. aurita occurs in areas surrounded by great proportions of open area matrix, unfavorable to movement, and close to C. jacchus populations. In other words, this demonstrates isolation of the native species in preserved areas increasingly surrounded by unfavorable matrix, along with an approximation of a more generalist and potentially invasive species. The results ensure the need to include landscape attributes and allochthonous species into C. aurita conservation studies, besides indicating urgency towards the allochthonous species management.