Does nest predator activity predict the location and survival of songbird nests in urbanizing landscapes?

Abstract

ABSTRACT Songbirds are under strong pressure to choose nest locations that reduce the risk of nest predation and, as such, are expected to use a variety of information sources to guide decisions about nest sites. The activity patterns of potential predators in the local vicinity should be one especially important source of information, although this may vary in urban ecosystems with altered predator–prey relationships. We examined the extent to which predator activity was associated with the nest distribution and survival of Northern Cardinals (Cardinalis cardinalis) and Acadian Flycatchers (Empidonax virescens) in 13 riparian forests situated across a gradient of urbanization in central Ohio, USA, in 2008–2010. We focused on a suite of diurnal predators that was responsible for >70% of songbird nest depredations in our study system. By overlaying nest locations of cardinals (n = 334) and flycatchers (n = 60) on predator utilization distributions created from mapped predator locations at each site, we det...