To minimize disturbance, capture only pups that are directly 

 beneath the catwalk. If pups are noosed at some distance away from 

 the catwalk (2-3 m), they cannot be lifted from there but must first be 

 dragged beneath the catwalk. Mothers will chase pups that are 

 dragged away, and the resident males will often chase the females. 

 Great injury and disturbance can result from these chases. By the end 

 of July or the first of August both females and pups are too wary of 

 humans to permit further captures from a catwalk. 



FEEDING OF CAPTIVE ANIMALS IN 

 PERMANENT FACILITIES 



Holding and feeding captive fur seals requires a considerable 

 investment in time (particularly in the early stages), and usually 

 results in less than 100% success with all animals. In planning for our 

 needs for captives, we generally anticipate that 20 to 25% of those 

 animals brought in will not learn to eat in captivity and will have to be 

 released. Adult females should not be held longer than 8 or 9 d with- 

 out food. Other researchers have also noted that some northern fur 

 seals are slow to begin feeding in captivity (Bigg et al. 1977; Spotte 

 1980). 



We keep herring and squid frozen at 0°F or below until the day of 

 use. Protein breakdown in the thawed fish appears to be rapid which 

 may decrease the nutritional value and reduces the acceptability of 

 the food. No fish is kept frozen more than 1 yr. Although we have 

 made no attempts to find out what the maximum consumption would 

 be, we have found that females fed 5-7 kg of whole fish per day do 

 not appreciably lose weight over a period of a month to 6 wk. Diet is 

 supplemented by vitamin tablets ("Sea-tabs") specifically formu- 

 lated for marine mammals. These tablets are inserted into the body 

 cavity of a herring before it is fed to the seals. Because seals may pass 

 the first food of the day through their systems quickly, (Kooyman 4 ) 

 we introduce the vitamin-supplemented fish sometime near the mid- 

 dle of the feeding session. Seals may not eat all the fish given in a 

 feeding session and hence may miss a vitamin dose given late in the 

 session. 



During the first few days of captivity the animals are particularly 

 sensitive to the presence and movement of nearby humans. To avoid 

 this distraction, we generally try to stay out of sight of the animals 

 during the first few feeding sessions. Our animals are trained to take 

 dead fish while swimming. Animals are allowed into the feeding 

 tanks and are given a few minutes to acclimate to the new surround- 

 ings. Then from a position out of sight (in the rafters above the tanks) 

 fish are dropped one at a time into the water close to the swimming 

 seals. For the first few sessions, interest in the food shown by the 

 seals appears to be little more than curiosity. They may take the fish 

 into their mouths, but generally do not eat. Occasionally a seal hauled 

 out on a resting platform above the water may enter the water to 

 investigate a fish dropped in the water nearby, but more typically this 

 happens after the animals have learned to eat the dead fish. 



The animals do not learn to accept dead fish at the same rate. At 

 times it may prove valuable to experiment with putting a noneating 

 seal in the same tank with a seal which has learned to feed (see also 

 Spotte 1980). The amount of aggression displayed by different seals 

 may vary widely. Once all the animals are eating, it may be necessary 

 to keep more aggressive animals separate from less aggressive ones 

 to more evenly distribute the food. 



The amount offish eaten and the portion of the fish consumed var- 

 ies from day to day and among different seals. Sometimes only fish 



*G. L. Kooyman. PRL. Scripps Institution of Oceanography, La Jolla. CA 92037. 

 pers. commun. February 1981. 



bodies are eaten: heads are bitten off and discarded. Occasionally 

 seals will tear open the fish and consume only the livers. Most fre- 

 quently we have seen animals eat entire fish for the first two or three 

 offered on a given day, then begin biting off the heads and eating only 

 the bodies. (This should be considered when fish are supplemented 

 with vitamin tablets.) Seals usually begin by taking only one or two 

 fish in the first feeding session. Good feeders rapidly increase to 3 or 

 4 kg per day in two or three sessions. Some appear to be insatiable, 

 but if fed to satiation they will develop diarrhea and stop eating. It is 

 best to increase the amount of food by a modest amount each day 

 when a seal begins feeding. 



Once the animals have begun to accept dead fish, the feeder may 

 begin throwing fish into the tanks from a visible position. Eventually 

 seals can be encouraged to eat at the near edge of the tank, and some 

 will finally learn to take fish directly from he feeder's hand. The 

 value of this training (especially if more than one seal is fed in a tank 

 at one time) is that the amount of fish consumed by each animal can 

 be monitored more accurately. 



The degree of success with inducing seals to feed, and the amount 

 of continued successful feeding may depend upon stresses placed 

 upon the animals between feeding times. We recommend that the ani- 

 mals be disturbed as little as possible between feeding sessions for the 

 first several days while they are still learning to accept dead fish in 

 captivity. 



One- and 2-yr-old subadult male seals have also been held in cap- 

 tivity and have learned to feed on dead fish. For experimental pur- 

 poses these young males were taught to take fish while out of the 

 water. This is not recommended as a normal procedure for feeding 

 since animals choke on the loose scales. 



LITERATURE CITED 



BIGG. M. A.. I. B. MACASKIE, and G. ELLIS. 



1977. Studies on captive fur seals. Fish. Res. Board Can.. Pac. Biol. Stn., 

 Nanaimo, B. C., Manuscr. Rep. Ser. 1422, 29 p. 

 CHEVALIER-SKOLNIKOFF, S., and F. E. POIRIER 



1977. Primate bio-social development. Garland Publ. Co., N.Y., 636 p. 

 GENTRY, R. L. 



1975. Comaparative social behavior of eared seals. Rapp. P. -V. Re'un. Cons. 

 Int. Explor. Mer 169: 188-194. 



GENTRY, R. L., and J. H. JOHNSON. 



1978. Physical restraint for immobilizing fur seals. J. Wildl. Manage. 42: 944- 

 946. 



GPJBEN, M. R. 



1979. A study of the intermixture of subadult male fur seals Callorhinus 

 ursinus (Linnaeus 1758) between the Pribilof Islands of St. George and St. 

 Paul, Alaska. M.S. Thesis, Univ. Washington, Seattle. 191 p. 



HOBBS. L. and P. RUSSELL (editors). 



1979. Report on the Pinniped and Sea Otter Tagging Workshop, 18-19 January 

 1979, Seattle Washington. Natl. Fish Wildl. Lab., Natl. Mus. Nat. Hist., 

 Wash.,D. C.,48p. 



JOHNSON, A.M. 



1971. Recoveries of marked seals. In Marine Mammal Biological Laboratory, 

 fur seal investigations, 1970. p. 26-31. Natl. Mar. Mammal Lab., Northwest 

 and Alaska Fish. Cent., Natl. Mar. Fish. Serv., NOAA, Seattle, Wash. 

 KEYES, M. C. 



1965. Pathology of the northern fur seal. J. Am. Vet. Med. Assoc. 147: 1090- 

 1095. 

 KOOYMAN. G. L.. R. L. GENTRY, and D. L. URQUHART 



1976. Northern fur seal diving behavior: a new approach to its study. Science 

 (Wash., D. C.)193:411-412. 



RONALD, K., and A. W. MANSFIELD (editors). 



1975. Biology of the seal: proceedings of a symposium held in Guelph 14-17 

 August 1979. Rapp. R -V Re'un. Cons. Int. Explor. Mer 169. 557 p. 

 SPOTTE, S. 



1980. Acclimation of adult northern fur seals (Callorhinus ursinus) to captivity. 

 Cetology 36:1-8. 



15 



