Introduction

Breeding and wintering exclusively in North America, the Surf Scoter was until recently one of our least-known seaducks. Bellrose (1980: 402) wrote, “Of all the ducks in North America, the Surf Scoter has the dubious distinction of being the least studied. It is indeed a blemish on the record of twentieth-century ornithologists and wildlife biologists that most of the available information on nesting dates back to the nineteenth century and is only fragmentary.” Within the last 10–12 years (1985–1997), however, many aspects of the ecology, distribution, and behavior of this species have been documented for the first time.

Breeding in northern Canada and Alaska and wintering along the East and West Coasts of North America, the Surf Scoter eats aquatic invertebrates on its breeding grounds and mollusks in spring, fall, and winter, as do other North American scoters. Outside its breeding range, the Surf Scoter occurs in flocks of various sex and age composition, molting in large concentrations at specific sites located in coastal waters. The species breeds on freshwater lakes, where males defend a moving area around the female. Females with broods are not territorial. Accidental exchanges of young among broods are frequent on crowded lakes, and reproductive success may fluctuate widely between years, mostly in response to weather conditions.

The first and only extensive study on the breeding ecology of Surf Scoters has just been completed (Morrier et al. 1997). Before this study, most accounts were anecdotal and concerned mostly the distribution and migration of the species (Savard and Lamothe 1991). Studies on staging or winter ecology and habitat use are few (Stott and Olson 1973, Bédard et al. 1997a, Falardeau et al. 1998), but courtship behavior and feeding habits have been well documented (Cottam 1939, Myres 1959a, 1959b, Stott and Olson 1973, Vermeer 1981, Vermeer and Bourne 1984). Only a few Surf Scoter nests have been described to date, and much remains to be learned about this endemic North American waterfowl.