Print PageUrbanization is rapidly and profoundly altering the world, leading to changes in the fundamental mechanisms that structure communities of wildlife. Top down influences (i.e., predation) could be one such mechanism that is affected by urbanization. Recent research has suggested a predation paradox is occurring in urban environments, where predation may be lower in more urbanized habitats while the number of predators may actually be higher. Here, we review the evidence to assess the validity of the predation paradox, focusing on songbirds.
Results/Conclusions
We found that nest and adult survival rates generally are similar or higher in more developed landscapes, and behavioral indicators also support the idea that predation pressure is lower in more urban settings. Predator responses to urbanization are taxon-specific, but several native species and introduced predators have increased in abundance with urbanization, leading to overall predator numbers being greater in more urbanized areas. Changes in diet have been noted for a number of urban predators, and this shift away from native birds as prey may help explain the predation paradox. Based on these findings, we present a modified framework for considering the role of predation in structuring urban wildlife communities that also incorporates bottom up factors, including the availability and abundance of different food resources.
