12 



NORTH AMERICAN FAUNA 74 



At the same time, rising water temperatures in southeastern Rering Sea lead to 

 more rapid melting of ice at the southern border of the pack and the beginning of 

 general recession northward. To the north, there is loosening of the pack in all 

 areas. 



Dispersion of walruses from their areas of winter concentration is abundantly 

 evident throughout the pack ice in April. Those animals that winter in the 

 Rristol-Kuskokwim Ray area begin to move northward along the Alaskan coast; 

 apparently those in the Pribilof area begin their migration northwestward 

 toward the Gulf of Anadyr. The major concentration of animals to the south and 

 west of St. Lawrence Island disperses more into the Gulf of Anadyr, and 

 especially northeastward toward Rering Strait. 



A small, third concentration in the western Rering Sea, east of Gape Navarin, 

 was indicated by Kenyon's (1972) data. Probably, this group overwintered along 

 the Koryak coast, southwest of Gape Navarin, and was bound for northwestern 

 Anadyr. A similar concentration was sighted in this same area in April 1979, and 

 other small groups, including females with calves, were present on the Koryak 

 coast (G. A. Fedoseev, personal communication). Judging from the general 

 tendency for northward movement in April, I presume the Koryak animals move 

 northward to Kresta Ray. 



To the north, the first walruses appear in Kresta Ray, and large numbers are 

 present in Rering Strait. A few have been sighted at the latitude of Point Hope 

 (S. J. Harbo, J, Swiss, personal communication) and rarely near Rarrow (J. J. 

 Rums, personal communication). A single male sighted near the northwestern 

 corner of Ranks Island in early April (Stirling 1974) certainly was one that had 

 overwintered there, rather than having been part of the vanguard of northward 

 migrants. Distributional extremes in the southern Rering Sea include a herd 

 sighted in Korf Ray, northern Kara gin Gulf in 1968 (Kosygin and Sobolevskii 

 1971), and large herds (about 100 each) sighted on Amak Island near the 

 southwestern end of the Alaska Peninsula in 1962 and 1969 (K. W. Kenyon, 

 K. R. Schneider, personal communication). In addition, there have been at least 

 three extralimital records for April from the North Pacific Ocean: an adult 

 female in Uyak Ray, Kodiak Island, in 1954 (R. A. Ryder, personal communica- 

 tion), a subadult female in the Knik River, near Anchorage in 1964 (F. H. Fay, 

 unpublished data), and a herd on Egg Island, Shumagin Islands, in 1979 (G. A. 

 Smith, personal communication). 



May (Fig. 8) 



Ry late April or early May of most years, formation of new ice ceases in the 

 Rering Sea, and melting of the submerged parts of the floes becomes evident not 

 long thereafter, even in Rering Strait. At the same time, surface winds become 

 much weaker and more variable in direction, which usually leads to cessation of 

 the general north-to-south trend of ice movement. Ry the end of May, the ice 

 that had covered nearly the entire shelf of the Rering Sea for the previous 

 4 months is reduced to a few large, wind-rafted masses of heavy floes that 

 generally cover less than one-fourth of that area. Meanwhile, in the Ghukchi 

 Sea, a major flaw opens widely along the northwestern coast of Alaska, and 

 there is increasing occurrence of open leads and polynyas in the area between 

 Point Hope and Rering Strait. 



