Hatching Success and Nest Site Characteristics of Black Skimmer (<i>Rynchops niger</i>) on the Isles Dernieres Barrier Island Refuge, Louisiana

Abstract

Barrier islands provide numerous ecosystem functions and services, including critical breeding habitat for many waterbird species. Louisiana's barrier islands are experiencing rapid land loss and habitat degradation. Restoration of barrier islands has become a high priority in Louisiana and barrier island degradation has increased waterbird reliance on restored dredge material islands. To improve restoration and management of barrier islands, we investigated the hatching success of Black Skimmer (Rynchops niger) and determined important habitat characteristics for their hatching success. Nest monitoring and nest habitat characteristics were measured at breeding colonies on the Isles Dernieres Barrier Island Refuge, Louisiana, in 2009 and 2010. Hatching success varied greatly for Black Skimmers (1–84%). Predation, flooding, and competition were the three main causes of nest failure. Habitat modeling identified nest elevation relative to the high-tide line and distance to high-tide line as important habitat characteristics. Continued restoration to build landmass on the islands is necessary to maintain quality nesting areas for Black Skimmers. Additionally, dredge applications to increase elevation, vegetation management, and predator control can provide more quality habitat and increase hatching success.