Distribuição do maracanã-verdadeiro Primolius maracana (psittacidae): preferência de hábitat e fatores que influenciam na manutenção de sua populações remanescentes. / Distribution of blue-winged macaw primolius maracanã: habitat preferences and factors affecting the persistence of its remaining populations.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

The blue-winged macaw is a vulnerable psittacidae, which has been suffering a rapid reduction of its populations in different parts of its occurrence. Thus, it was carried a detailed revision on the, historical and current, distribution and estatus of the species through using literature and specimens in museums data. We gathered 176 records of blue-winged macaw sites and compared its historical and current distributions. We verified a range contraction in the south limit of blue-winged macaw’s historical occurence. In this way, we evaluated if, in this zone, the blue-winged macaw’s occurrence is correlated to composition and structure of residual vegetation. The current occurrence of the species was related to geographic coordinates and landscape indices of 54 localities, through the logistic regression analysis. The "total of vegetal cover of the landscape" was the only feature of the landscape significantly related to blue-winged macaw’s occurrence (p<0,01), however its explicatory power was very low. The "latitude" was highly significant to predict blue-winged macaw’s occurrence (p<0,001), and also was not related to any analyzed landscape metric. This suggests the existence of another non-evaluated factor, with spatial structure highly related to latitude, affecting the southern populations of blue-winged macaw. Also we studied the occurrence pattern of blue-winged macaw in local scale, around of Caetetus Ecological Station (2178 ha). This reserve is placed in a mosaic of landscape, consisting of small remnants of native vegetation that may have some value to the specie’s maintenance. We sampled 36 of these remaining areas through the method of countings in advantage points. Each remnant got a "blue-winged macaw’s visit index" that was related to spatial remnants features and its surrounding landscape, through the linear regression model. The landscape features around of the fragments explained more the variation of the bluewinged macaw’s visit index than the features of the fragments itself. The "index of visits of maracanãs" was directly related to "distance to the closest city" (p<0,05) and to "remnant size" (p<0,05), and inversely related to "distance to the closest known roost of blue winged macaw " (p<0,01) and "shortest distance to the Caetetus Ecological Station" (p<0,05). All these analyses indicate that the conservation of the landscape as a whole seems to be critical for the maintenance of blue-winged macaw’s populations, in local and regional scale. However the size of the remnants and its spatial configuration must be taken in account, besides the efforts for the conservation of the roost sites.

ASSUNTO(S)

psitaciformes ecologia animal wildlife population biologia animal população animal aves wildlife biology psitacideae forest ecosystem habitat proteção animal wildlife protection habitat birds ecossistema florestal wildlife ecology

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