Flexible nest‐site selection under anthropogenic habitat change in an Afrotropical understorey insectivore

Abstract

Human activities impact upon natural habitats used by birds for breeding and foraging, and lead to changes in the composition and spatial distribution of predator communities, mainly through loss, fragmentation and disturbance of formerly pristine habitat. Yet possible fitness consequences of such changes through impacts on bird nest‐site selection remain poorly known. Here we study nest‐site selection and reproductive success of Placid Greenbuls Phyllastrephus placidus in the Taita Hills, southeast Kenya. We show that habitat features associated with nest‐site selection by this insectivorous, open‐cup‐nesting bird species vary among forest fragments that are exposed to different levels of habitat disturbance. Such differences in sites selected for breeding result from a plastic response to fragment‐specific conditions or may be driven by fragment‐specific variation in the distribution and availability of certain habitat features. Given the overall high nest predation rates in our study area, we expected variation in nest‐site selection to correlate with reproductive success and nestling condition, but detected no such relationship. Because predator density and nest predation rates may vary strongly in space and time, a better understanding of spatio‐temporal variation in predator communities is needed to assess the possible adaptive value of nest‐site selection strategies for reducing the high predation rates that are typical for this and many other open‐cup‐nesting tropical passerines.