Age at First Breeding Buffleheads probably breed for the first time at 

 the age of 2 years (Erskine 1972). 



Mortality of Eggs and Young Nests may be destroyed by large predators 

 (bears) or robbed by small ones (mustellids, squirrels). Competitors for nest- 

 ing cavities (flying squirrels, birds) may cause the loss or desertion of nests 

 and eggs. Some nests are deserted after intrusion by other Buffleheads or by 

 Barrow's Goldeneyes that lay in the same cavity (Erskine 1972). Some young 

 fail to leave the nest cavity or to reach water. Erskine (1972) suggested that 

 large carnivorous fish, especially the northern pike ( Esox lucius ) , may take 

 the ducklings. 



Renesting There is no good evidence that Buffleheads renest after the 

 loss of a clutch (Erskine 1972). 



Maximum Natural Longevity Birds banded in British Columbia have been 

 found alive up to nine years after banding (Erskine 1972). A bird recovered at 

 Sled Lake, Saskatchewan, had reached an age of at least 14 years and 3 months 

 (Clapp et al . in press). 



Weight Averaged over the year, male Buffleheads weigh about 1 lb (450 g) , 

 and females weigh about 0.73 lb (330 g) (Erskine 1972). 



SUSCEPTIBILITY TO OIL POLLUTION 



Buffleheads have been involved in a few oiling incidents (Table 12). King 

 and Sanger (1979) suggested that this species may be adversely affected in the 

 waters of the Pacific Northwest, but they thought that the damage probably would 

 not be catastrophic. This species seldom forms large aggregations and is fair- 

 ly uncommon in much of the southeastern United States. Consequently, we think 

 that there is no major hazard to the Bufflehead population from development of 

 petroleum resources in most of the southeastern United States. Only in the 

 colder waters of North Carolina, the state harboring more wintering Buffleheads 

 than any other in the southeast, are these ducks likely to suffer significant 

 mortality from oil pollution. 



BIBLIOGRAPHY 



1981 



Bolen, E. G. and B. R. Chapman. 1981. Estimating winter sex ratios for Buffle- 

 heads. Southwest. Nat. 26: 49-52. 



1980 



Lirapert , R. J. 1980. Homing of adult Buffleheads to a Maryland wintering site. 

 J. Wildl. Manage. 44: 905-908. 



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