Date of this Version
Prairie Naturalist (December 1983) 15(4): 145-154.
Breeding habitat of the least tern is made up primarily of coastal beaches and inland river sandbars. Populations of the interior (Sterna antillarum athalassos) and east coast (S. a. antillarum) subspecies are now declining (Marshall et al. 1975, Duffy 1977, Jernigan et al. 1978) and the western subspecies (S. a. browni) is endangered (Wilbur 1974). Although coastal populations have received considerable attention (Wolk 1974, Atwood et al. 1977, Blodgett 1978), little research has been conducted on the interior race (Hardy 1957, Downing 1975).
The piping plover inhabits river sandbars and sand beaches and, like the least tern, breeding populations are declining (Arbib 1975, 1978, Niemi et al. 1977). Of the two races, little is known about the interior population (Charadrius melodus circumcinatus) (Pickwell 1925, Renaud 1974, Niemi and Davis 1979).
In Nebraska, the Platte River has historically supported breeding populations of least tern and piping plover (Bent 1929), and both species are found where sandbars are present (Downing 1975). Changes in adjacent land use including increased use of center pivot irrigation systems, and in the water regime of the Platte River, have resulted in reduced availability and quality of sandbar breeding habitat. This is primarily the result of reduced water levels and the subsequent encroachment of woody vegetation within the river channels (Currier 1982). Williams' (1978) study of Platte River channel shrinkage described changes that have occurred in peak discharges, annual flow, channel width, and bed elevations between 1865-1978. Current annual flows are about 69% reduced from pristine times (Krapu et al. 1982).
The objectives of this study were to: 1) determine the distribution and abundance of least tern and piping plover using the Platte River in central Nebraska, 2) quantify selected parameters associated with their nesting habitat, 3) evaluate the impact of changing land use on tern and plover nesting habitat, and 4) suggest management alternatives for least tern and piping plover breeding habitat.