Abstract

Northern fur seals have not been kept successfully in captivity. Young animals have not achieved normal growth, and full grown adults have not adapted or survived. We are conducting a study to determine how to achieve dietary intake and other husbandry considerations sufficient to sustain normal growth and longevity.

Preliminary results indicate that northern fur seals are more active and hungry at night, would not compete well with other pinnipeds for food, and prefer to be aloof from humans. Notes

Fur seals don't adjust well to captivity. They refuse to eat, must be force-fed, don't gain weight and eventually die. While they are pups they accept stomach tubes and are fed formula, however, it is difficult to wean them onto fish.

Since fur seals are capricious eaters and spit out their fish a few times before swallowing, they should not be housed with Phoca or Zalophus. These latter species will eat the fur seal's fish.

Fur seals take 75-80% of their food after dark. They are nocturnal feeders, preying on schooling fish which rise to the surface at night. Their eyes are adapted for gathering light, so bright light hurts their eyes and they squint in the daytime. Thus color and depth of the pool are important. Stay away from bright reflective colors because they are optically painful to seals. During captivity, the dark brown pigment of the iris changes to light lavender, possibly due to bright light conditions.

One may get seals used to eating squid by throwing a live one in. After eating a live one they often accept dead ones. Hand-fed animals will eventually eat on their own but don't rush them or starve them too soon for training because they can be thrown into a fasting state. The male seal should get all the fish it wants during the period of maximum growth.

There may be a physiological need to experience water pressure (to eliminate all air periodically from the lungs) so seals should have a minimum pool depth of 15 feet.

There are several postulated reasons for poor growth of captive fur seals. They are poor competitors for food and do poorly in cohabitation with other species. Fur seals are usually hand-fed when young and become used to this. Finally, a low food intake is maintained to keep the seals hungry for optimum training. Thus it is suggested that it is not a good idea to train fur seals since reducing their food intake aggravates poor growth rates.

Young fur seals will likely adapt to captivity, but adults are not likely to adapt.