Effects of structural and functional connectivity and patch size on the abundance of seven Atlantic Forest bird species

A Uezu, JP Metzger, JME Vielliard - Biological conservation, 2005 - Elsevier
A Uezu, JP Metzger, JME Vielliard
Biological conservation, 2005Elsevier
We studied the importance of fragment size and structural and functional connectivity on the
occurrence and abundance of seven Atlantic Forest bird species in 13 patches (13–275ha)
and three sites within a continuous forest (10,000 ha). We sampled birds with point counts
and evaluated structural connectivity considering the presence of corridors and the degree
of isolation. We defined functional connectivity by analyzing species movements using
playbacks in forest corridors between fragments and in the surrounding matrix. Species …
We studied the importance of fragment size and structural and functional connectivity on the occurrence and abundance of seven Atlantic Forest bird species in 13 patches (13–275ha) and three sites within a continuous forest (10,000ha). We sampled birds with point counts and evaluated structural connectivity considering the presence of corridors and the degree of isolation. We defined functional connectivity by analyzing species movements using playbacks in forest corridors between fragments and in the surrounding matrix. Species differed in their responses to fragmentation. For the frugivorous species, Trogon surrucura, Carpornis cucullatus and Triclaria malachitacea, patch size was the main factor determining abundance. Two understory insectivorous species, Basileuterus leucoblepharus and Pyriglena leucoptera, were more affected by the degree of patch connectivity, the former by the presence of corridors and the latter by the distance between patches. The capacity of P. leucoptera to use corridors and open areas (i.e. functional connectivity) shaped its abundance pattern. Fragmentation had no effect on the abundance of Chiroxiphia caudata and had a positive effect on Batara cinerea. This study emphasizes the importance of considering species’ perceptions of landscape, especially functional connectivity, in understanding the effects of habitat fragmentation.
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