ECOLOGY AND BIOLOGY OF THE PACIFIC WALRUS 



11 



Fig. 6. Walruses sighted in March (symbols as in Fig. 4). 



Conceivably, a third, smaller group exists along the Koryak coast, southwest of 

 Cape Navarin (cf. Fig. 7), but no data are available from that sector in March. 



The distribution at this time probably is much the same as it is in February, 

 but there are suggestions of some initial movement northward, especially in the 

 vicinity of St. Lawrence Island and Bering Strait. The first sightings north of 

 64°N and east of 170°40'W were recorded in March, though in only 4 of 17 

 winters between 1956 and 1972. Large numbers also were sighted there in March 

 1976 (H. W. Braham, personal communication). In some years, an increase in 

 numbers from February to March also was seen in the vicinity of Bering Strait, 

 near and to the north of the Diomede Islands. The most northerly sightings were 

 of two animals near Barrow, Alaska (H. Melchior, personal communication), 

 and of a few males just west of Point Hope (Manville 1961; S.J. Harbo, personal 

 communication). The southernmost sightings were near the Pribilof Islands 

 (F. H. Fay, K. W. Kenyon, unpublished data). At this time also, a few indi- 

 viduals have been seen near shore along the southern coast of Chukotka 

 (Belopol'skii 1939; Nikulin 1941) and off the Alaskan coast near Hazen Bay and 

 Tununak (K. W. Kenyon, R. Tremaine, personal communication). 



April (Fig. 7) 



With the increasing angle and duration of solar radiation and lighter, more 

 variable winds, the weather over the Bering Sea is appreciably warmer in April 

 than in the previous months, and the rate of formation of new ice is diminished. 



