THE SEA OTTER IN THE EASTERN PACIFIC OCEAN 25 



to early spring period indicates no statistically significant differ- 

 ence in body condition (table 2). The sea otter must maintain a 

 high daily intake of food regardless of season. It is reasonable to 

 suppose that those animals capable of maintaining themselves 

 under the feeding conditions imposed by a maximum otter popu- 

 lation would show little seasonal differences in body weight. 



WEIGHT LOSS PRECEDING DEATH 



Death, in the wild and in captivity, is usually preceded by a 

 period of physical deterioration evidenced by gradual or precipi- 

 tous loss of body weight. The mean weight of 13 adult males found 

 dead on Amchitka beaches was 47.1 lb. (21.4 kg.) (table 4). The 

 mean weight of 79 adult males that were shot near the same places 

 was 62.5 lb. (28.3 kg.) (table 2). The mean weight difference was 

 15.2 lb. (6.9 kg.), indicating that preceding death the moribund 

 animals lost 24 percent or about one-quarter of their body weight. 

 Similarly, between 254 adult females that were shot and 17 that 

 were found dead on beaches the mean weight difference was 10.8 

 lb. (4.9 kg.) (21.1 kg. minus 16.2 kg., tables 2 and 4), or an indi- 

 cated reduction of about 23 percent. 



Seventeen adult sea otters (10 males and 7 females) were 

 weighed at capture and again after they died in captivity. These 

 animals were held captive for periods varying from 6 days to 

 10 months (tables 5 and 6). Among 10 adult males that died in 

 captivity, the mean weight loss at death was 24 percent of the 

 body weight at capture. Three animals in this group lost 30 per- 

 cent or more of their body weight (table 5) . Data for adult females 

 are similar (table 6). 



Massive weight loss preceding death appears to result from 

 (1) evacuation of the gastrointestinal tract, (2) consumption of 

 body fat reserves, and (3) dehydration. The usual terminal symp- 

 toms, in wild and captive animals, was excretion of black, tarry 

 feces due to enteritis. 



After an adult otter enters a period of physical decline, the 

 restoration of normal vigor and weight may be difficult or impossi- 

 ble by any knov^ means. The afflicted animal may become in- 

 creasingly lethargic and may consume little or no food. Some 

 emaciated juveniles captured on beaches, however, recovered when 

 given adequate food in captivity. 



In summary, there is evidence that among adult otters of about 

 the same body length, those from areas of sparse population 

 may weigh about 16 to 28 percent more than apparently healthy 

 animals from a densely populated area and about 50 percent more 



