A Multi-Scale Analysis of Competition between the House Finch and House Sparrow in the Southeastern United States

[摘要] Abstract. The decline of House Sparrow (Passer domesticus) populations in eastern North America has been proposed to be a consequence of competition between the House Sparrow and the House Finch (Carpodacus mexicanus), both introduced species. Previous research testing the hypothesis that House Sparrow declines are due to competition with House Finches focused on populations in the northeastern U.S., excluding other regions where the species coexist. We tested for effects of competition between these two species in the southeastern U.S. at two scales of analysis. First, we looked for evidence of competition at a local scale during the breeding season by examining patterns of co-occurrence of House Finches and House Sparrows at count points within a 28.3-km2 study area centered on Auburn, Alabama. Second, we tested for the effects of competition at a regional scale across seven southeastern states by analyzing trends in Christmas Bird Count data. Using null-model analysis, we found no evidence for competit...

[学科分类] 动物科学

[关键词] Carpodacus mexicanus;co-occurrence;House Finch;House Sparrow;interspecific competition;invasive species;Passer domesticus