There is little information on demographic trends of, or threats to the Wilson's Plover (Charadrius wilsonia), despite concerns that habitat degradation may be causing the species to decline. I studied Wilson's Plover demography, nest site selection, and physiological and behavioral responses to overflights at Cape Lookout National Seashore, North Carolina, where the National Park Service and U.S. Marine Corps recently lowered the altitude for overflights at tactical speeds. I monitored the responses of incubating Wilson's Plovers to overflights and other human activities and compared heart rate, incubation rate, and vigilance behaviors during time periods with and without these stimuli. I compared habitat use vs. availability at the island-scale, and nest placement relative to geomorphic features and vegetative cover, both on a local and island-wide scale. Wilson's Plovers increased vigilance during military rotary-wing and civilian fixed-wing overflights, but not during military fixed-wing overflights. Plovers were vigilant more and incubated less when researchers were present. Wilson's Plovers selected for interdune areas, flats and isolated dunelets on flats, and against beach and dunes. At the local scale, nests were more likely to be near dense vegetation than random points. Mayfield nest survival was 25%, and predation caused most of the nest failure. Daily nest survival was negatively correlated with nest age and initiation date. Nests with cameras and heart rate monitors had lower survival, and nests with predator exclosures had higher survival. The mean number of chicks fledged per pair was 0.78. / Master of Science

The Wilson’s Plover (Charadrius wilsonia) is a species of concern in most southeastern U.S. coastal states, where it breeds and winters. The U.S. Shorebird Conservation Plan listed this species as a Species of High Concern (Prioritization Category 4), and the U.S. Fish and Wildlife Service has designated it as a Bird of Conservation Concern (BCC). Despite its conservation status, Wilson’s Plover population trends are poorly understood and little research has been conducted examining habitat factors affecting this species’ breeding and foraging ecology. I collected Wilson’s Plover demographic data and explored which habitat characteristics influenced breeding success and foraging site selection among three coastal habitat types (i.e. fiddler crab (Uca spp.) mud flats, beach front, and interdune sand flats) at Onslow Beach, Marine Corps Base Camp Lejeune, North Carolina, 2008-2009. I observed little difference between years in nest success (≥ 1 egg hatched), failure, and overall nest survival. The majority of nest failures were caused by mammalian predators. For those nests that hatched successfully, greater proportions were located in clumped vegetation than on bare ground or sparsely vegetated areas. In-season chick survival for both years was higher for nests that hatched earlier in the season, and for nests farthest from the broods’ final foraging territory. Productivity estimates (chicks fledged per breeding pair) were not significantly different between years (0.88 ± 0.26 fledged/pair in 2008, 1.00 ± 0.25 fledged/pair in 2009) despite a shift in foraging behavior, possibly related to habitat alterations and availability in 2009. My findings indicate that Wilson’s Plover adults and broods were flexible in establishing final foraging territories; in 2008 all final brood foraging territories were on fiddler flats while in 2009, final foraging territories were sometimes split between fiddler flats, beach front, and interdune sand flats. For those Wilson’s Plovers establishing territories on fiddler flats, area of the flat was the most important feature explaining use versus non-use of a particular flat; area ≥ 1250 m² was preferred. Close proximity to water and vegetative cover were also important habitat features in foraging site selection on fiddler crab mud flats, and in all habitat types combined. My findings will directly contribute to population and habitat research goals outlined in the U.S. Shorebird Plan and will supplement limited data about foraging and habitat use related to Wilson’s Plover breeding ecology. / Master of Science