Nest‐site selection and demography of Wilson's Plovers on a North Carolina barrier island

Despite concerns about their population status, information about the habitat preferences, population size, and vital statistics of Wilson's Plovers (Charadrius wilsonia) is currently lacking. We compared habitat characteristics of nest sites and unused sites and examined factors affecting nest success on a barrier island in North Carolina in 2010 and 2011. We monitored 83 nests with cameras and added heart‐rate monitors in artificial eggs to 36 of these nests for a concurrent study of the effects of jet overflights; predator exclosures were placed around 17 of the nests with cameras. Wilson's Plovers used interdune areas, flats, and isolated dunelets on flats more than expected based on availability, and nests were located closer to dense vegetation than unused sites. Nests in interdune areas had higher daily survival rates than nests on flats, but distance to dense vegetation did not affect nest survival. Nests without cameras, heart‐rate monitors, or exclosures had a 35% predicted probability of hatching at least one egg. Exclosed nests had higher daily survival rates than nests without exclosures, but daily survival rates were lower for nests with cameras or heart‐rate monitors and for nests initiated later in the season. Daily survival rates also declined as nests aged. The predicted probability of fledging was 74%, resulting in a reproductive output of 0.78 fledglings/pair. Apparent annual adult survival was 77%, and the apparent annual survival rate for birds banded as chicks was 42%. Additional research is needed throughout the range of Wilson's Plovers to determine if populations are stable or decreasing, and to predict the productivity rates needed to maintain current populations. However, our results suggest that in our study area, predator removal and protection of sparsely vegetated overwash habitats will likely have the greatest impact on reproductive output.