Female site familiarity increases fledging success in Piping Plovers (Charadrius melodus)

Abstract

Reproductive success commonly improves with age in birds. However, it is difficult to determine whether this phenomenon is due to breeding experience or other age-related factors because most potential explanatory factors are positively correlated. Using a 17-year database, we investigated how age, breeding experience, location experience, and pair-bond experience influenced Piping Plover (Charadrius melodus) reproductive success in the Great Lakes region. Reproductive success was measured as number of offspring fledged per pair for 415 successful nests during 1993-2009. We controlled for individual and site variation with random effects and tested for increased reproductive success associated with age, prior breeding experience, prior location experience, and prior pair-bond experience using generalized linear mixed models. Reproductive success increased with locationspecific breeding experience of females and declined when females moved to a new location. After statistically controlling for these effects, we found no additional effect of male age, male experience, or pair experience. Additionally, fledging success declined with later hatching dates, so we examined the relative influence of age and experience on hatch date and determined that older females and males bred earlier. Our results indicate that improvement in reproductive success with age in Piping Plovers has two components: a direct effect of female location experience on fledging success, and an indirect effect of timing of breeding, which leads to greater reproductive success through earlier nesting by older males and females. Actions by resource managers to promote breeding philopatry and successful early nesting attempts may enhance reproductive success of this federally endangered population. © 2012 by The American Ornithologists' Union. All rights reserved.