Differences in patch use behavior between an urban and rural species: Effects of distance from shelter and wing molt-gaps Academic Article uri icon

abstract

  • It has been suggested that urban bird populations and communities are controlled by bottom-up mechanisms because predation costs are lower in urban than in non-urban habitats. We hypothesized that urban birds are less sensitive to variations in the cost of predation than non-urban birds. We predicted that the house sparrow, a widespread urban species, is less sensitive to variations in predation risk, while foraging, than its rural (less urban) congener, the Spanish sparrow. We quantified foraging behavior of these species, as affected by the proximity to shelter, in large outdoor aviaries. We then clipped feathers from the birds' wings to manipulate escape ability and increase predation risk. We predicted that birds experience increasing predation risk with increasing distance from shelter, and that reduced wing surface increases the birds' sensitivity to risk of predation with respect to distance from shelter. Both species displayed increasing giving-up densities in seed trays with increasing distance f...

publication date

  • January 1, 2009