2 



NORTH AMERICAN FAUNA 74 



at least 15 months. Females tend to breed at 2-year intervals or less often and are 

 most productive between the ages of 8 and 15 years. The principal causes of mor- 

 tality appear to be predation, intraspecific trauma, and microbiological in- 

 fections. The Pacific walrus population was severely depleted in the late 19th 

 century and again in the mid-20th century by overharvests for commercial 

 purposes. Over the past 20 years, it apparently has recovered rapidly, in response 

 to reduced harvest. The sex ratio of breeding adults appears to be about 

 1 male:3 or 4 females. The crude birth rate in recent years is estimated at 17 ± 

 2%, and the survival of young to puberty appears to be very high. 



Introduction 



One of the most remarkable creatures in the Arctic is the walrus {Odohenus 

 rosmarus), whose very existence and natural history were cloaked in mysticism 

 and anthropomorphism until the 19th century (Gray 1853; Allen 1880; 

 Cammann 1954). For thousands of years, this mammal was regarded by Eskimos 

 and other native people of the North as having supernatural powers and human 

 attributes. At the same time it was for them a natural resource of major 

 importance. From the walrus they obtained food and fuel, as well as materials 

 for making tools, shelters, boats, sleds, and clothing. In all probability, the 

 harvesting of walruses by these indigenous people before the 18th century had 

 little impact on the populations. The primitive hunter was not equipped to kill 

 great numbers of these animals and had no incentive to take more than were 

 required to meet his own daily needs. 



A new era of exploitation of walruses and other animal resources of the 

 northern seas was heralded in the North Pacific region by the arrival of 

 European man in the 17th century. Finding rich, untapped resources in the 

 Bering Sea, he came later in capacious ships and with the firearms and the 

 economic incentive to take all that he could obtain. He did so for the next two 

 centuries, as though the supply were endless (Fay 1957). From the Pacific walrus 

 (O. r. divergens), the principal commodities taken were ivory, oil, and hides. 



By the end of the 19th century, the walrus population was severely depleted, 

 and in 1951 when my study was conceived, there seemed to be no indications of 

 its being restored. Although commercial harvesting of walruses by American 

 industries had all but ceased more than 35 years earlier, there were suggestions of 

 continued decline of the population. That trend was reversed a decade later, but 

 at the time when I began my work, the Pacific walrus appeared to be on the road 

 to extinction. My primary goals then were to assess the status of the population 

 and to identify the forces that were suppressing it. Of necessity, much of my 

 emphasis was placed on supportive studies of the biology and ecology of this 

 mammal. There was a dearth of such information in the literature at that time. 

 The results of my work, up to 1979, make up the bulk of this report. Relevant 

 published and unpublished information from other sources up to December 1978 

 has been included. This publication is not, however, an attempt to review all 

 available information. 



I began my field work in April 1952 in the Eskimo village of Gambell 

 (Seviiokak) on the northwestern tip of St, Lawrence Island (Fig. 1). I chose that 



