THE SEA OTTER IN THE EASTERN PACIFIC OCEAN 321 



On 20 May, seven otters, including four females and three males, 

 were taken to St. Paul Island by direct flight (see Transportation 

 of Captives, Aircraft). They weighed 26 to 36 lb. and were esti- 

 mated to be 1 to li/o years old. They were marked with numbered 

 monel tags on the hind flippers. The animals were liberated at 

 Polovina Point within 20 minutes after landing. All appeared in 

 excellent condition and, except for one, each accepted and ate a 

 fish as it swam from shore. When liberated, the animals scattered. 



On 21 May, D. L. Spencer and I watched one otter for some time 

 from the cliffs of Reef Rookery (3 miles from the point of release). 

 This animal was eating a large sea urchin and appeared contented 

 and in good health. A brief aerial survey of a part of the west and 

 south sides of St. Paul was made after takeoff on 21 May. Two 

 additional otters were seen at this time ; however, several thousand 

 fur seals in the area made it difficult to distinguish otters. 



Subsequent reports indicate that this transplant was partially 

 successful in that the animals survived for a substantial period 

 after liberation. Several observations of them were reported during 

 the remainder of 1959 and in 1960. The last authentic sighting of 

 one otter was by an experienced hunter, Maxim Buterin, in the 

 spring of 1961. He saw it near the same place on two occasions. 



Why these transplanted animals did not ultimately survive and 

 reproduce is problematical. Two possible explanations may be 

 considered: (1) Seven immature otters may be too small a nucleus 

 to form a reproducing colony. Before they matured (estimated 

 2 to 3 years after liberation) too few survived natural attrition 

 to form a colony. (2) The Pribilofs are at the northern limit of 

 the species original range. Hardship caused by winter ice, as 

 described by Nikolaev (1965) might be expected to have caused 

 mortality. 



In August 1965, John Vania and Edward Klinkhart, of the 

 Alaska Department of Game, captured 41 and held 35 otters in a 

 floating netted enclosure supported by a wooden frame and styro- 

 foam floats in Constantine Harbor at Hinchinbrook Island in 

 Prince William Sound, Alaska. Free circulation of water and a 

 plentiful supply of food assured excellent survival in the holding 

 facilities. The animals were transported 450 miles in a Grumman 

 Goose Amphibian aircraft after receiving injections of a tran- 

 quilizer "Tranvet." During the 3.7-hour flight distress caused by 

 overheating occurred. This problem of overheating was solved by 

 constructing a container for water into the cages but 12 otters 

 died in flight prior to the pen modification. On the last flight, after 

 the cages had been modified, seven otters were transported. All 



