SNOWY PLOVERS SELECT OPEN HABITATS FOR COURTSHIP SCRAPES AND NESTS

The population decline of the Western Snowy Plover (Charadrius alexandrinus nivosus) along the Pacific coast of the U.S., has been attributed, in part, to the spread of European beachgrass (Ammophila arenaria), which degrades nesting habitats. We compared Ammophila cover at the plover's courtship scrapes and nest sites with that at random locations in coastal northern California. Ammophila cover around nests and scrapes was significantly less than random points at several spatial scales (<= 100 m) of analysis; cover around nests was also less than around scrapes. Incubating plovers ceased incubation and left nests when an observer approached to within a mean distance of 80 +/- 33 m (n = 8). We conclude that the plover's selection of open habitats for courtship and nesting may facilitate early detection of predators. Our results indicate a minimum size for restoration projects and a distance at which fencing around nests should be placed to ameliorate the effects of human disturbance on incubating plovers.