(1) Generally metal levels were higher in the salt gland for mallard and black duck, and in the liver for greater scaup.
(2) During February and March, 1974, an epizootic involving lesser scaup (Aythya affinis) occurred in the Tampa Bay area on the west coast of Florida.
(3) Pintails and lesser scaup gave the poorest results, and pekin duck, black duck, and redhead duck were intermediate.
(4) Concurrent with this epizootic was a red tide caused by heavy blooms of the toxic dinoflagellate Gymnodinium breve intoxication were evident in some of the lesser scaup.
(5) The concentrations of Fe, Zn, Mn, Cu, Pb, Cd, Co, Ni, Cr and Ag in 88 samples of various bones and five samples of trachea prepared from scaup ducks (Aythya marila L.) have been determined.
(6) In comparing tissues cobalt was higher in the salt glands than in livers of all three species; chromium and nickel were higher in the salt gland than liver for mallard and black duck; and lead, manganese and zinc were higher in the liver than the salt gland in greater scaup.
(7) These lesser scaup specialists exhibit interactive patterns amongst themselves and, to some extent, with avocet specialists.
(8) Levels of nine heavy metals were measured in the livers and salt glands of greater scaup (Aythya marila), black duck (Anas rubripes) and mallard (A. platyrhynchos) from Raritan Bay, New Jersey to determine if the functioning avian salt gland concentrates heavy metals.
(9) Adults of Profilicollis botulus were found in 6 species of diving ducks in British Columbia including 3 new hosts: common goldeneye, Bucephala clangula (L.); Barrow's goldeneye, B. islandica (Gmelin); and greater scaup, Aythya marila (L.).
(10) A comparison of susceptibility to experimental infection with C. bushiensis revealed that mallards (Anas platyrhynchos), black ducks (Anas rubripes), blue-winged teal, pintail (Anas acuta) and lesser scaup (Aythya affinis) had similar susceptibilities but that wood ducks were significantly less susceptible to infection.
(11) In contrast, avocets collected from permanent bodies of water in Alberta had communities composed largely of species that are specialists in various duck species, particularly lesser scaup.
(12) A controlled experimental feeding of G. breve toxic material to White Pekin ducklings produced illness and death with signs comparable to some of those seen in the scaup.