Population Studies of Piping Plovers at Lake of the Woods, Minnesota: 19 Year History of a Declining Population

-We determined population status and reproductive success of Piping Plovers (Charadrius melodus) at Lake of the Woods, Minnesota during 1988-2000. This is the only remaining breeding population of Piping Plovers in the state and is the last geographic link between the Great Lakes and Northern Great Plains populations. Previous studies, beginning in 1982, recorded populations of up to 50 birds at this location in 1984. Since then, despite intensive management attempts to improve reproductive success, numbers have gradually declined to a low of six birds in 1997. Of 88 nests monitored over 13 years, 54.6% hatched, 18.2% were depredated, 13.6% were destroyed by storm waves and 13.6% were abandoned. The number of chicks fledged per breeding pair ranged from 0.0-2.7 (K = 1.1) among years. Varying water levels either exposed broad sandy beaches or led to inundation of Piping Plover nests and substantial erosion of breeding habitat. Management activities included seasonal posting of sanctuaries, trapping of mammalian predators, destruction of Ring-billed Gull (Larus delawarensis) nests, use of elevated string gull deterrents, use of predator exclosures around nests, destruction of American Crow (Corvus brachyrhynchos) nests, and removal of trees and shrubs. Despite these efforts, during most years, fledging rates have been below those believed necessary for population stability. Received 31 March 2000, accepted 3 August 2000.