Data from: Threshold effect of habitat loss on bat richness in cerrado-forest landscapes

Understanding how animal groups respond to contemporary habitat loss and
fragmentation is essential for development of strategies for species
conservation. Until now, there has been no consensus about how landscape
degradation affects the diversity and distribution of Neotropical bats.
Some studies demonstrate population declines and species loss in impacted
areas, although the magnitude and generality of these effects on bat
community structure are unclear. Empirical fragmentation thresholds
predict an accentuated drop in biodiversity, and species richness in
particular, when less than 30% of the original amount of habitat in the
landscape remains. In this study, we tested whether bat species richness
demonstrates this threshold response, based on 48 sites distributed across
12 landscapes with 9 to 88% remaining forest in Brazilian cerrado-forest
formations. We also examined the degree to which abundance was similarly
affected within four different feeding guilds. The threshold value for
richness, below which bat diversity declines precipitously, was estimated
at 47% of remaining forest. To verify if the response of bat abundance to
habitat loss differed among feeding guilds, we used a model selection
approach based on Akaike's information criterion. Models accounted
for the amount of riparian forest, semideciduous forest, cerrado, tree
plantations, secondary forest, and the total amount of forest in the
landscape. We demonstrate a nonlinear effect of the contribution of tree
plantations to frugivores, and a positive linear effect of the amount of
cerrado to nectarivores and animalivores, the groups that responded most
to decreases in amount of forest. We suggest that bat assemblages in
interior Atlantic Forest and cerrado regions of southeastern Brazil are
impoverished, since we found lower richness and abundance of different
groups in landscapes with lower amounts of forest. The relatively higher
threshold value of 47% suggests that bat communities have a relatively
lower resistance to habitat degradation than other animal groups.
Accordingly, conservation and restoration strategies should focus on
increasing the amount of native vegetation of landscapes so as to enhance
species richness of bats.