Amazonian countryside habitats provide limited avian conservation value

Balancing ever-increasing agricultural and biofuel needs with biodiversity conservation is one of the greatest challenges facing conservation biologists in the 21st century. The conversion of >75 million hectares of forests in Brazilian Amazonia over four decades for agropastoral uses has resulted in the ‘creation’ of a similar-sized amount of non-forest ‘agricultural matrix’ habitats. Despite extensive research on the effects of forest loss and fragmentation on the Amazonian biota, the value of increasingly larger areas of non-forest habitat for forest wildlife remains poorly understood. We conducted 325 fixed-radius point counts of the avifaunal assemblage of non-forest vegetation within a 1200-km² region along the Amazonian ‘Arc of Deforestation’ in Northern Mato Grosso, Brazil. Our sampling included 2,814 records of 164 species, 15 and 54% of which were recorded in more than 10% and fewer than 2% of all sampling sites, respectively. In particular, nearly 70% of the regional scale avifauna of 560 species failed to use the agricultural matrix, regardless of the persistence of ameliorating structural features, such as isolated trees. At the local scale, higher species richness in the agricultural matrix was best predicted by the presence of relictual trees, and to a lesser extent by standing water and scrubby habitats. The presence of relictual trees, rather than scrub, predicted the occurrence of those forest-dependent species that did use the agricultural matrix. Our results indicate that intensive agricultural production coupled with land sparing would better suit conservation of vulnerable forest species than more extensive ‘wildlife friendly’ agricultural practices that require more land under production to produce the same yield.