in areas other than the southeast. 



HABITAT 



Nesting The Bufflehead is one of the few hole-nesting ducks and is conse- 

 quently associated with forests in its breeding distribution. These ducks nest 

 primarily in mixed coniferous-deciduous woodlands north and west of the Great 

 Plains (Palmer 1976b). Palmer (1976b) indicated that Buffleheads typically nest 

 in or by small, shallow, fresh or slightly alkaline bodies of water that have 

 little emergent vegetation around their margins. Erskine (1972) characterized 

 lakes used for breeding as moderately to highly eutrophic, and indicated that 

 Buffleheads avoid both shallow, weedy sloughs and large, deep, gravel-shored 

 lakes . 



Nest density is closely related to the presence of deciduous trees con- 

 taining Common Flicker ( Colaptes auratus ) holes, especially aspen. Flicker 

 holes are preferred, but holes excavated by Pileated Woodpeckers ( Dryocopus 

 pileatus ) are also used. Burned areas and parkland groves of aspens which sup- 

 port large numbers of nesting Flickers also support large numbers of Buffleheads. 

 Few nest far from water or in dense forest (Palmer 1976b). 



Most of 205 nests found in breeding areas from Alaska to California and 

 Saskatchewan were found in in Quaking Aspen ( Populus tremuloides - 52.2%) and 

 Douglas Fir ( Pseudotsuga menziesii - 21 . 5%)(Erskine 1972). 



Feeding Buffleheads prefer to feed in shallow water, with most feeding 

 done at depths of about 6-10 ft (1.8-3.0 m)(Erskine 1972). 



Winter and Offshore Buffleheads seek out sheltered portions of the marine 

 habitat for winter, avoiding the more exposed coasts. They particularly favor 

 shallow waters over mud flats that are exposed at low tide. Habitats utilized 

 range from secluded coves, river mouths, and shoals along flat Gulf shores to 

 the icy edges of rocky coasts (Erskine 1972). Wintering Buffleheads may occur 

 quite far from shore and may winter on sheltered salt water, slightly brackish 

 water, and on inland fresh water just south of the areas in which most such 

 waters freeze (Palmer 1976b). 



FOOD AND FEEDING BEHAVIOR 



Buffleheads feed predominantly by diving, using the feet for propulsion 

 (Erskine 1972). They have also been seen wading in shallow water seizing food 

 with their heads submerged beneath the water and also seizing food at the sur- 

 face (King 1976). In another instance, a flock was seen up-ending on the Indian 

 River at Cape Canaveral (King 1976). Buffleheads may dive for food individually 

 but when in flocks often exhibit synchronized diving. Most dives take 15-25 sec 

 in water 6-10 ft (1.8-3.0 m) deep; dives may average as little as 10 sec in 

 shallower water. 



Palmer (1976b) summarized Erskine 's (1972) fine synthesis of the feeding 

 habits of the Bufflehead by stating that "The Bufflehead feeds primarily on 



411 



