Translation 2783

. 156
are to be seen on coastal stretches t;lat have been favoured by the
animals for a long time. bome . well-separated groups of unhated-males
and of females with young are known to exist on Mednyi island and
in the Kurile Islands; Further differentiation of the groups of
females with young into two subgroups has been observed, one of these
consisting of pregnant females with new-born.young and the other of
females with well-grown cubs. It is believed that the adult males
remain separate except during the mating period. As. Compared with
related genera, the «sea otter is a .peace-loving animal with a well- -
instinct. - •
developed co-operative
• • The reproductive biology of the sea otter has not been fully
studied, on account of the difficulty of approaching the animals for
year-round - observations in natural conditions. Although females with
new-born young may be seen at practically any time throughout the
year, parturition by the majority of the females in the Komandorskie .
and Kurile populations takes place in May and June. The young are
brought . forth on shore or among rocky islets projecting above the
water. Cases have also been recorded of young being born in dense
beds.of seaweed in the water. The birth process lasts only for a few
minutes.
Asa rule a female produces a single cub, although - eases are .
known of two embryos being found in a uterus. The cubs are born with
eyes open, with all their milk-teeth, and with dense light-brown fur.
They live a fairly passive life for a long period and spend most of •
their time sleeping;, they do not go into the water independently, and
cannot swim activelY. During the entire lactation period the mothe r .
constant care of her,offspring; she feeds them well with milk, takes
drags them from the rocks if danger threatens, teaches tnem to swim
actively , . and so on. The duration of the lactation period iù unknown,
as'also is the time when the . cubs make the transition to an independent
mode•of life. It is believed that most of the females abandon
their young in autumn, as observations Of cubs with their mothers in
november and. December are quite rare. Probably, therefore, the lactation
period lasts for four or five months some cases of females
feeding eubs of other mothers.have been recorded.
•
Uourtuhi9 dlaj and matin by the adultG ap!,arently take place .
, end of the lactation .perioa_ It IG eoliuvr2d that in the
at UK