Bird assemblages in anthropogenic habitats: Identifying a suitability gradient for native species in the Atlantic Forest

ZURITA, G.A.; BELLOCQ, M.I.

BIOTROPICA

WILEY-BLACKWELL PUBLISHING, INC

Año: 2012 vol. 44 p. 412 - 419

0006-3606

Traditional approaches to the study of species persistence in fragmented landscapes generally consider a binary classification of habitat as suitable and non-suitable; however, the range of human-modified habitats within a region may offer a gradient of habitat suitability (or conservation value) for species. We identified such gradient by comparing bird assemblages among contrasting land uses (pine plantations of different age, annual crops, clearcuts and cattle pastures) in the Upper Parana Atlantic forest. Birds and vegetation structure were sampled in an extensive area of 4400 km2 in Argentina and Paraguay during the breeding season of 2004-2010. Bird assemblages similarity between anthropogenic habitats and native forest and the proportion of forest species increased with vegetation vertical structure, while the proportion of open-area species decreased. As a consequence, mature tree plantations were the most suitable habitats for forest species and were mainly used by frugivores and bark insectivores. In contrast, open habitats were the least suitable habitat for forest species and were used mainly by insectivores species. Structurally complex human-modified habitats can be exploided by a sub-group of forest species and, in some cases, increase functional connectivity and mitigate the consequences of the edge effect; however, the conservation of large tracks of native forest is critical for the long term persistence of the entire bird assemblage.