Draft Baseline Report - Least Turn and Piping Plover Section

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Piping plovers forage visually, by picking and gleaning, for invertebrates at the substrate surface in open, wet, sandy shorelines areas of rivers, alkali wetlands, and other water bodies (Lingle 1988). Prey Species Corn and Armbruster (1993) identified several patterns of invertebrate distribution and abundance relative to piping plover foraging along the central Platte River between Lexington and Grand Island at 11 study sites (6 sandpits and 5 river channel reaches) in 1988, and at 12 sites (6 sandpits and 6 river channel reaches) in 1989. Of these sites, 4 of the 6 sandpit sites were used for nesting and foraging, all of the river reaches were used for foraging, and no river reaches were used for nesting. Diets of piping plovers were determined by describing the invertebrate fauna on areas where plovers were known to forage. Invertebrate distribution and abundance were determined by sampling the strata that were used significantly more than other areas at each study site. The dominant invertebrate taxa collected on sticky boards from both site types consisted of shore - inhabiting and semi - aquatic species associated with moist, sandy environments. Observations of plover foraging activity indicated that the birds appeared to track soil moisture of the foraging substrate. Plovers using sandpits concentrated their foraging effort along the sandpit shoreline, where soil moisture was highest. Plovers foraging on river channel sites, where soil moisture did not vary with distances from water's edge, tended to forage at all distances from the water's edge. Corn and Armbruster found that invertebrates are distributed more or less uniformly across the foraging habitat on river channel sites, but decline with increasing distance from water's edge on sandpits. The patterns of invertebrate occurrence resulted in greater foraging activity on river channel sites by piping plovers. Lingle (1988) reported that piping plovers appeared to prey on invertebrates of all sizes both on dry substrates and along the waterline. Fecal samples that were collected and examined contained body parts from beetles. Adult piping plovers were observed feeding on grasshoppers and terrestrial beetles (Lingle 1988). Foraging Movements Piping plovers generally forage within one mile of their nest site (Lingle 1988). Banded piping plovers nesting at sand pits have been observed foraging at the river approximately %2 mile from their nests (Lingle 1988). Mortality/ Nest Success Least Tern Mortality Lingle (1993a) examined factors contributing to nest failures and poor recruitment (high chick mortality) and compared success between riverine and sandpit colonies. Effects of river stage on tern and plover nests and /or chicks along the 80 mile reach of the Platte Draft Baseline Report, July 2002 4 -10