lULl.. ~~C'(fh"-<Y.~~\J Stlll~~JW&'VLt.:..l' Olf' PREDATORY HABITS OF ATLANTIC WALRUS c-n p~ ~~ ~ .J IU.K.Timoshenko (SevPINRO), L.A.Popov (VNIRO) n{)AltMti_ jIO.-~ W.JJ\.W'1 -~) WI Predators are known to exist among walruses. There is n~~o~~~O;> ~p tion in literature,however, on any direct observation on the attack I of walruses on other warm-blooded animals, except for the case repor- ted by Pedersen (Pedersen,I962). roo the data available are of particUlar interest. The observations were made on board vessels,helicopters and on ice in the White Sea in the sealing season of the harp seal. Here some examples will be given. ~ young walrus was encountered on the ice in the Nack of the White ~ea at a distance of 34 km west of the Village of Nizhnyaya Zolotitsa on March 4,1983. ~eeing pea.ple it crept down into water. The ice floe was stained with blood. Many traces found on the· snow covering the ice floe evidenced the predator's movements. Some fragments of a white-coat harp seal,e.g. head and fore flippers, were found. A similar caRe when a walrus attacked a harp seal was recorded in March 1976 (Popov,Nazarenko,I977). At that time the observation made on board a helicopter registered a fact that a young male at the age 3 or 4 years emerged from water and trod on a pup of harp seal who stayed on the ice floe without its mother, and disappeared with the pup in water. In March 1984 the observers on board s/v MEZEN saw a walrus chasing a female of harp seal in the Funnel of the White Sea. The female with a pup were lying on a small ice floe and attracted the walrus's attention. The walrus emerged from water from different sides of the floe trying to reach the female. The latter caring after the pup moved from one edge of the floe to another. Unfortunately their behaviour could not be followed any longer because the walrus was frightened by the vessel and disappeared in water. On March 8,1988 a walrus emerged from water attacked a female - 2 - of harp seal lying with a pup on the edge of the ice floe, killed the 'female and pushed her into water. Then the walrus attacked the pup and tore it to pieces. It took place in the north-east of the White Sea proper. It should be noted that a sealer stood near the female and her pup,but it did not affect the aggressive intentions of the predator. One more case, on April 24,1988 a walrus attacked a killed harp seal that lay on an ice floe on the molting ground situated in the south part of the Funnel of the White Sea, and pulled it into water. Experienced sealer~ hunting for marine animals in the south- east part of the B~rents Rea for a long time note that bearded seal and ringed seal leave their areas if walruses approach them. Of interest are cases when sealers found the remains of pups of harp seal (skin with blubber) in the stomachs of walruses in the.past. It is likely that due to these facts and similar cases the sealer6t belief that walruaes feed on seals has been strengthened. While discussing the predatory behaviour of the Atlantic walrus froD the Barents Sea population attention should, be paid to another' circumstance. It seems that the distribution pattern of walruses migrat- ing in the White Sea in sprinR (March-April) coincides by and large with the localities of breeding and molting ground~ of harp seal. In fact, in r.larch walruses occur somewhat further' south than in April,i.e.. in the north-east part of the sea proper,in the Neck and in the south part of the Funnel of the Sea. It is in these areas that pups of harp seal are born. The evidence is also supported by frequent records of the oocurrences of walruses on the breeding groundA of seals. For 'example, three walruses were observed among breeding harp seals in the north-east part of. the sea proper in the first 10- day period of March 1988. They stayed in water,but got sometimes out, onto the ice. Three more walruses were found in the south-west part of the Funnel of the sea - 3 and one walrus was encountered in the south-west part of the I~ck of the sea among pups of the harp seal when the lactation period was ove~' in late March 1988. Besides, one walrus was registered on the pup roockery situated west of the Morzhovets Island in the first 10-day period of March 1989. The evidence of the interrelatiQn~etween the localities of pup roockeries of harp seal and walruseg:~eupported also • I by the fact that when rookeries drift intensively to the nQrth under' the influence of southerly winds,e.g.in 1989, walruses do not; penetrate far in the White Sea and occur' in northern areas. And in contrast to that, in years when roockeries of harp seal are forme~ and stay iru tlie 80uth areas of the White Sea for a long time,as it happened i~ 1988, walruses also penetrate furthe~ south in; the sea. The record indicates one case when a young walrus was enoounterea on the molting ground of harp seal in the Barents Sea in May 1979. Of partioular interest is the faot that walruses occur in the White Sea precisely at the moment when harp seal stay' in the area,i.e_ in March-April-May. According to our obser~ations some part; of the' Barents Sea. population of walrus' spends' winter' in the South-East Ba- rents Sea,that is in the area where migratiom routes of the harp seal are,when they migrate along the ice edge to the breedin~ grounds ift the White Sea. It is likely that this fact iB responsible for' the movement of certain] walruses to the White Sea following schools of harp seals. The data obtained enable us to change somewhat our attitude to- ward the predatory habits of walruses,at least toward. the Atlantic populatio~ It is evident that predation and aggressive behaviour' of the Atlantic walruses toward harp seal and probably to other' species of pinnipedB should be considered as a fairtT common phenomenon rather' than the fate of' individuals aB it seemed earlie~~ One of the reasons of predation in walruses is assumed to be the lack of food in their habitat. o - ~ (t-2 • -3 Fig.1·Location on where wharuses where met in the White Se~.