Demographic, ecological, and life-history traits associated with bird population response to landscape fragmentation in Europe

Abstract

Human land-use transformation has fragmented natural landscapes around the world, with fragmentation currently being considered a global threat to biodiversity conservation. Landscape fragmentation, however, does not affect all species similarly, suggesting that some species characteristics may render species more sensitive to fragmentation than others. The aim of this study was to test whether demographic, ecological, and life-history traits are associated with vulnerability to landscape fragmentation in European breeding bird species. Effective mesh size per area unit was used as an index of landscape fragmentation. Vulnerability to fragmentation for every bird species was estimated as population response to fragmentation per se (controlling for habitat loss due to fragmenting elements), with more vulnerable species showing a negative relationship between population density and fragmentation among countries, and less vulnerable species showing no (or even a positive) relationship. Comparative analyses controlled for similarity among species due to common phylogenetic descent. Response to fragmentation was more often positive than negative, and it was positively related to population size, migration distance, and body mass, and negatively related to age at first reproduction. The relationship between response to fragmentation and population size did not allow us to assess whether being less abundant was the cause or the consequence of being vulnerable to fragmentation. Response to fragmentation was not significantly related to other demographic, ecological, and life-history characteristics. These results suggest that small-sized resident bird species with delayed maturity are particularly vulnerable to landscape fragmentation. Future conservation efforts should target these species.