Aerially spraying ponds with carbaryl (Sevin-4-oilR) at 840 g active ingredient/ha reduced biomass and numbers of macroinvertebrates and decreased the growth rates of American black duck, Anas rubripes, and mallard. Anas platyrhynchos, ducklings in Maine. Ducklings on sprayed ponds spent more time searching for food and less time resting, and their rate of movement around the ponds was greater than for ducklings on unsprayed ponds.
Two female American Black Ducks (Anas rubripes) were initially observed during June 1982 with 20 Class Ib or 18-22 Class Ia-b ducklings in two wetlands in Hancock County, Cherryfield, Maine. Fifteen of 20 ducklings (75%) in one brood and 16 of 18-22 ducklings (72-89%) in the other brood survived to fledge. These large broods probably resulted from post-hatch brood amalgamation.
Extraordinary Size and Survival of American Black Duck, Anas rubripes, Broods