ECOLOGY AND BIOLOGY OF THE PACIFIC WALRUS 



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1953. A. C. Heinrich (personal communication) reported a "tumor of the 

 womb" in another animal taken in the same locality. Tumors of the cervix seem 

 to be relatively common in Pacific walruses, for I have seen at least four in 240 

 uteri from animals 2 years old and older. The largest of these, about 15 x 20 cm, 

 had fully occluded the left uterine horn, which contained about 2 L of purulent 

 fluid (Fig. 135). The right horn of this specimen, however, remained fully 

 functional, as indicated by the presence of a recent (2- to 3- week-old) placental 

 scar and associated large corpus albicans in the ovary. 



Cystic Ovaries 



Cystic ovaries occur infrequently. I have seen three cases, drawn from a 

 sample of more than a thousand adult females examined by Burns (1965 and 

 unpublished data) and me. In each case, the cysts apparently were of long 

 standing, since they were filled with caseous, necrotic material. In two cases, 

 only one ovary was affected; in the third, both ovaries were totally affected, and 

 the animal consequently was sterile. 



Umbilical Hernia 



A beached carcass of an adult female, found on the southern shore of Bristol 

 Bay by R. A. Dieterich and L. M. Shults (personal communication) had a 

 herniated umbilicus, through which had emerged part of the uterus and of the 

 fetus therein (Fig. 136). The adult appeared otherwise to have been in excellent 

 condition. Presumably, the herniation had been caused by trauma. 



Fig. 136. Umbilical hernia in an adult female walrus. Extrusion of part of the uterus and 

 hind limbs of the full-term fetus (arrow) through the ruptured abdominal wail 

 apparently had caused the death of this animal, shown here in posteroventral view. The 

 two holes in the right abdominal wall were made by scavengers at the mammae. The 

 base of the right hind limb is visible at left. (Photo by R. A. Dieterich) 



