Meeting Abstract
To help forestall coastal erosion, Louisiana’s Coastal Protection and Restoration Authority has instated beach renourishment programs, which help reduce the risk of storm surge for coastal marsh and human communities and provide ideal habitat for nesting Least Terns because they vastly increase the area of sparsely vegetated open beach. Previous data have suggested, however, that beach restoration has a mixed effect on nest success for these birds. Increased presence of mesopredators, which leads to lower hatching success, may in some circumstances create a population sink associated with restored beaches, but nests on restored beaches also appear less likely to be destroyed by floods and storm surge. We tested these predictions on Elmer’s Island, in which the Caminada Headlands Phase II dune renourishment project was completed in late 2016. To quantify the effects of restoration on nesting success, we used program MARK to calculate daily nest survival (DNS) for 287 nests monitored in summer 2017, and modeled nest success with DNS evaluated at different intervals. Nest elevation, storm surge, predator density, and substrate/vegetation surrounding nests were used as covariates. Interactions between extreme high tide events and depredation risk may be complex, such that understanding these interactions and how restoration affects these risks is an important pursuit in researching the effects of coastal restoration on beach-nesting birds.
