Interspecific variation in nest survival is not driven by nest predator identity or nest-site characteristics in shrub-nesting birds

Considerable attention has been focused on factors influencing spatiotemporal variation in avian nest survival. Despite focus on causes of nest failure within species, relatively little consideration has been given to variation in nest survival among species nesting within closeproximity. Predation is the leading cause of nest failure for most open-cup nesting passerines, and nests of different species within the same habitats may be susceptible to the same predator species. However, numerous factors, including the timing of nesting within the breeding season, nest height, nest-site habitat, and species-specific behaviors may influence the probability of nest predation. We examined causes of interspecific variation in nest survival in shrub-nesting birds at 12 sites in Illinois from 2011 to 2014. Using data collected from >2,000 nests of 7 different open-cup nesting passerines, including >350 video-monitored nests, we examined the importance of nest height, nesting date, habitat characteristics surrounding nest sites, and nest concealment on nest survival and predator identity. After controlling for these ecological factors, we examined whether adding species identity explained further variation in nest survival or predator identity. After controlling for date and aspects of the nest site, bird species were susceptible to the same suite of nest predators. Nonetheless, species exhibited considerable variation in daily survival rates even after accounting for nest-site characteristics. Given that these species were susceptible to the same nest predators, interspecific differences in nest survival likely reflect differences in predation rates resulting from interspecific behavioral differences.