The Masked Duck in the United States

Abstract

UNTIL fairly recently, the neotropical Masked Duck (Oxyura dominica) had been reported within the continental United States only a few times. Between 1857 and 1905 single accidental records of the species were made in Vermont, Massachusetts, Wisconsin, and Maryland (Bent, 1925). Only the Rio Grande area of Cameron County, Texas, where Fisher (1895) first reported the sighting of several Masked Ducks and the collection of a female specimen near Brownsville in July 1891, has been considered a potential breeding locality. Griscom and Crosby (1925) mention a male specimen, taken in the same place at the same time, and Lawrence (1927) reports a specimen killed in Brazoria County, Texas. A female Masked Duck was shot in Louisiana during December of 1933 (Lowery, 1955), one was reported near Harlingen (Cameron County), Texas in December of 1936 (Bird-Lore, 39': 65, 1937), and a flock of 24 was reported at Aransas National Wildlife Refuge (Aransas County), Texas in December of 1948 (Audubon Field Notes, 3: 177, 1949). As Masked Ducks are not known ever to have been kept in captivity in the United States (Delacour, 1959), it is unlikely that these early records represent escaped birds. In September 1937 Lo-etscher (1956) observed a group of eight Masked Ducks near Brownsville, including two males in nuptial plumage. Loetscher presumed that the five female-like birds may have included young of both sexes. Prior to 1941 L. I. Davis repeatedly observed single Masked Ducks near Harlingen, and, although no nest was located, he believed (1966) that they attempted to breed there in 1941, when five possible immatures were seen. These two cases apparently represent the only reported instances of possible breeding by Masked Ducks in the United States prior to 1967. During the 195Os three Masked Ducks were reported from Florida, including a bird found dead at Key West in 1955 (Hames, 1956), one shot during the 1956-57 hunting season in Glades County, and one shot during 1957 in Palm Beach County (Owre, 1962). Texas reports include a female seen near Santa Ana National Wildlife Refuge (Hidalgo County) during March of 1957 (A.F.N., 11: 362, 1957) and a female observed on Laguna Atascosa National Wildlife Refuge (Cameron County) in October of 1959 (A.F.N., 14: 53, 1960). The early 1960s brought about a surprising number of new Masked Duck reports, often shortly after the passage of Caribbean hurricanes. These included the sighting of a male on Brigantine National Wildlife Refuge, New Jersey, in December 1960 (A.F.N., 15: 315, 1961), a bird