Kristie Stein's Graduate Exit Seminar
We invite you to attend Kristie Stein’s Graduate Exit Seminar Tuesday, July 10th at 10 A.M. in 333 Kottman Hall.
She will be presenting Filling Gaps in the Full Annual Cycle of the Black-crowned Night-Heron (Nycticorax nycticorax)
As many as 60% of North American migratory birds are in decline, and populations can be limited during one or more stages of the annual cycle. These stages are often linked through carry over effects whereby individual fitness in a given stage is determined by events and experience in a preceding stage. Without knowledge of each stage, it is difficult to pinpoint factors that may pose challenges to declining populations. One species of migratory bird, the Black-crowned Night-Heron is of conservation concern throughout the Great Lakes region and within Ohio, the number breeding pairs and active breeding colonies has declined beginning in the 1970s, resulting in the species to be listed as state-threatened. We used automated telemetry to examine how conditions experienced within the nest carry over to influence survival during the post-fledging period of juvenile birds. We found that parental-mediated (e.g. growth rate, nest height) and species-specific (e.g. brood size, hatching asynchrony) traits influenced nestling survival, but not post-fledging survival. Instead post-fledging survival sex-biased, where females were less likely to survive the six months following fledging. We also examined the migratory and nonbreeding stages of adult night-herons using satellite transmitters. We found consistency in migratory routes, but strategies varied between individuals. Additionally, the nonbreeding distribution is large, with locations spanning five countries. The information that our research provided fills gaps our knowledge of the full annual cycle and can be used to inform conservation planning both within Ohio and in other declining populations.