to intrinsic differences in the sensitivity to habitat grain among
species, studies performed at different extent are necessary to
understand the consequences of forest loss and fragmentation. Using a
large database, we explored the responses of birds to changes in forest
cover and the role of habitat specialization in the strength of this
Southern Atlantic forest of Argentina, Brazil and Paraguay.
used data on bird occurrences recorded in 1,384 point counts
(2004–2011), estimated forest cover and number of forest fragments in
two radii (60 and 960 m), centred at each point count. For each bird
species, we extracted the geographical and altitudinal range as two
indirect measures of habitat specialization. We used general linear
model and Akaike information criterion to explore the influence of the
type of habitat, the amount of habitat and fragmentation pattern on the
probability of species occurrence and the influence of habitat
specialization on the strength of response.
the 28 species analysed, 15 (55%) responded either to forest loss or
the number of fragments, either positively or negatively. In these 15
species, the probability of occurrence of 67% was better explained by a
specific extent (either 60 or 960 m). The strength of the response to
forest loss decreased with both the geographical and the altitudinal
range of species.
study shows that a large proportion of species responded to forest loss
at a specific extent and that the magnitude of the response is related
to species specialization. A single-extent approach to multispecies
studies may not be enough to preserve the whole community due to
differences in sensitivity to habitat grain. Maintaining forest cover at
multiple extents and managing anthropogenic habitats to increase their
suitability for native species are essential to preserve communities in
highly fragmented landscapes such as the Atlantic forest.