ern Mississippi and eastern Louisiana coasts. Judging from the 1975 waterfowl 

 survey (Goldsberry et al. 1980), most of these birds occurred in Louisiana wa- 

 ters. Hamilton (1978) considered a concentration of 500 near Horn Island in 

 January 1978 unusually large. 



Louisiana Lowery (1974) stated that Redheads are uncommon winter residents 

 on inland lakes, but are occasionally observed forming rafts of several thousand 

 on the coast. Arriving in the state around the first week, of October, they re- 

 main until late April. Large numbers may winter along the eastern coast (Bell- 

 rose 1976). An incomplete survey in January 1975 found 1,000 Redheads in Loui- 

 siana (Goldsberry et. al. 1980). 



Texas From mid-October to mid-May, Redheads are locally abundant to com- 

 mon on the lower and central coasts, and irregularly common to uncommon else- 

 where in the state (Oberholser 1974). During the spring and fall, they are most 

 numerous in the northern two-thirds of the state. Bellrose (1976) considered 

 both the south Texas coast and that of adjacent Mexico important wintering areas 

 for this species. Large concentrations were found at the Laguna Madre of Texas 

 (300,000) and Mexico (60,000), and at Matagorda and San Antonio bays (20,000). 

 Goldsberry et al. (1980) reported that 438,290 were found on the January 1975 

 waterfowl survey. This figure represents 62.4% of all wintering Redheads count- 

 ed in the contiguous United States and Mexico, making Texas by far the most im- 

 portant wintering ground for the species. 



Sporadic nesting by a very few Redheads has been reported from inland 



Castro, Medina, and Lubbock counties. These records consisted of unfledged 



young seen in the months of August (3 of 5 records), November, and December 

 (Oberholser 1974, Rhodes 1979). 



SYNOPSIS OF PRESENT DISTRIBUTION AND ABUNDANCE 



Breeding Redheads breed solely in North America, most of them in an area 

 extending from southern Mackenzie and central and southern British Columbia 

 southeast to western Minnestota , northern Nebraska, and central Colorado, and 

 southwest to northwestern Nevada and central California (Small 1974, Palmer 

 1976b). 



Breeding populations on the principal prairie breeding grounds ranged from 

 387,000 in 1963 to 927,000 during the period 1955-74, and averaged 649,000 

 (Bellrose 1976). The 1976 waterfowl breeding ground survey indicated a breeding 

 population of at least 963,000 birds, the majority (67.3%) in southern Alberta 

 and southern Saskatchewan (Larned et al. 1980). This survey evidently did not 

 cover several states in which the Redhead is known to breed. Among these is 

 Utah, which contains the greatest concentration of nesting Redheads in North 

 America in the marshes near Great Salt Lake. According to figures provided by 

 Bellrose (1976), this area has more breeding Redheads (130,000) than all of the 

 rest of the western United States put together. 



Weller (1964) mapped densities throughout the breeding range of the Red- 

 head, finding that extreme drought in the primary nesting range of both the 

 Redhead and the Canvasback severely reduced the quantity and quality of breed- 



272 



