In the Old World, these mergansers breed in the northern Palearctlc from 

 Iceland, the Faeroes, and the British Isles through Scandinavia, Denmark, and 

 the Baltic States to Russia, northern Siberia, and the islands of the Bering 

 Sea (BOU 1971) . 



Bellrose (1976) reviewed estimates of populations of North American Red- 

 breasted Mergansers and derived from these a total summer population of 237,000. 

 Population estimates for northern Europe indicate a population of probably not 

 less than 13,000 pairs (Cramp et al. 1977). 



Winter In North America, Red-breasted Mergansers winter primarily along 

 the Atlantic, Gulf, and Pacific coasts from open waters of the breeding range 

 south to Baja California and coastal Sonora (Palmer 1976b), coastal Tamaulipas 

 (Saunders and Saunders 1949 in Leopold 1959), and southern Florida (Palmer 

 1976b). 



Bellrose (1976) used Christmas Count figures to estimate the proportions 

 of each species of merganser that were included in the estimates made during 

 January waterfowl surveys. He assigned 67% of the observations to Common Mer- 

 gansers, 25% to Red-breasted Mergansers, and 8% to Hooded Mergansers. He esti- 

 mated that a total of nearly 60,000 Red-breasted Mergansers wintered in the 

 four flyways: 38,000 (ca. 64%) in the Atlantic, 14,000 (ca. 24%) in the Missis- 

 sippi, 6,000 (ca. 10%) in the Pacific, and 1,100 (ca. 2%) in the Central Flyway 

 (Bellrose 1976). About 165,000 mergansers were counted in the contiguous United 

 States during the January 1975 waterfowl survey (Goldsberry et al. 1980). If 

 Bellrose' s method of estimation is valid, about 41,000 of these were Red-breast- 

 ed Mergansers, and more than half of them wintered in the waters off the south- 

 eastern states. 



Eurasian populations winter south to northern Africa, the Middle East, the 

 China coast, and Japan. About 40,000 winter in western Europe and the British 

 Isles, another 50,000 in the Mediterranean and Black sea regions, and 48,000 

 pairs in Russia (Cramp et al . 1977). 



Migration The majority of Red-breasted Mergansers that breed inland appar- 

 ently migrate toward the Atlantic or Pacific coasts to reach their principal 

 wintering grounds. A smaller proportion migrate into the Great Lakes region, 

 and from there move to either the Gulf or the mid-Atlantic coast. Those that 

 winter along the Texas coast apparently fly from central Canada south across 

 the Great Plains (Bellrose 1976). Cramp et al. (1977) summarized movements and 

 chronology of migrations for this species in the Old World. 



Fall migrants may appear in coastal areas to the north as early as Septem- 

 ber (Palmer 1976b) but the peak of fall migration along the southeastprn coast 

 occurs during the third week of November (Bellrose 1976), with some migrants 

 still moving past raid-December (Palmer 1976b). Spring migration occurs largely 

 from early March through May in the contiguous United States, with peak movement 

 from late March through late April (Palmer 1976b). Flocks of fall migrants may 

 consist of a few hundred birds or more, but flocks of spring migrants are usu- 

 ally smaller (Cramp et al. 1977). 



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