Journal Article

The traits that predict the magnitude and spatial scale of forest bird responses to urbanization intensity

Paton, Grant D., Gagné, Sara A., Wilson, Andrew M., Shoffner, Alexandra V.

2019

Overview

As humans continue moving to urban areas, there is a growing need to understand the effects of urban intensification on native wildlife populations. Forest species in remnant habitat are particularly vulnerable to urban intensification, but the mechanisms behind these effects are poorly understood. An understanding of how species traits, as proxies for mechanisms, mediate the effects of urban intensification on forest species can help fill this knowledge gap. Using a large point count dataset from the Second Pennsylvania Breeding Bird Atlas, we tested for the effects of species traits on the magnitude and spatial scale of the responses of 58 forest bird species to urbanization intensity in landscapes surrounding count locations. Average urbanization intensity effect size across species was -0.36 ± 0.49 (SE) and average scale of effect of urbanization intensity was 4.87 ± 5.95 km. Resident forest bird species that are granivorous or frugivorous, cavity-nesting, and have larger clutch sizes and more fledglings per clutch had more positive associations with increasing urbanization intensity in landscapes. In addition, the effect of urbanization intensity on forest birds manifested most strongly at larger spatial scales for granivorous, frugivorous, or omnivorous species that are cavity-nesting, have larger clutch sizes and longer wingspans, and flock in larger numbers. To our knowledge, the present study represents the first direct tests of the effects of species traits on both the magnitude and spatial scale of the effect of urbanization on forest birds, as well as the first evidence that migratory status, clutch size, wingspan, and fledglings per clutch are important determinants of the responses of forest birds to urbanization. We discuss the possible mechanisms underlying our results and their implications for forest bird conservation in urbanizing landscapes.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adaptation, Biological - physiology / Agriculture - trends / Amplification / Analysis / Animal behavior / Animal breeding / Animal Migration - physiology / Animals / Atlases as Topic / Biodiversity / Biology and Life Sciences / Birds / Birds - classification / Birds - growth & development / Birds - physiology / Blue jay / Body Size - physiology / Breeding / Cavity nesting / Clutch size / Clutch Size - physiology / Clutches / Demography / Earth science / Earth Sciences / Ecology and Environmental Sciences / Ecosystem / Feeding Behavior - physiology / Forest conservation / Forest management / Forests / Granivory / Habitats / Humans / Indigenous species / Juveniles / Landscape preservation / Metropolitan areas / Mortality / Nesting / Pennsylvania / People and places / Population Forecast / Proxy / Quantitative Trait, Heritable / Social Sciences / Success / Urban areas / Urban planning / Urbanization / Urbanization - trends / Wildlife / Wildlife conservation / Wildlife habitats / Wings, Animal - anatomy & histology