Translation 2783

• •
. 289
whales of the West African herd leave.the waters adjacent to the
-
coasts of the Congo, Angola, and South Africa in spring and head
for -U.s.e A.ntarctic, where they are found in summer from the South
Sandwich Islands to the Greenwich meridian. After winterinçe, the
• hales of the East African herd migrate south into the region east
of the Greenwich meridian approximately as far as 60 0 E.
At the
ond of summer the West Australian herd leaves the Antarctic (from
Co E to 110 ° or 120 ° E) for the region lying northwest of West
Australia.
The Coral Sea is the wintering-place for the whales of
the East Australian herd; they spend the summer in the Antarctic
from 140 0 E to 170 ° E, including Balleny Island.
The New Zealand
herd occupies the region eastward to 145 0 W; it winters in the seas
around the Fiji Islands and in the waters east of these.
While in their fattening-grounds in Antarctic waters blue
whales feed exclusively on Euphausia superba, one of the most abundant
species of Euphausiacea, which forms mass concentrations in -
these waters. The stomachs of different specimens have been found
to contain from one to one-and-a-half tons of krill. Other crustacean
species, such as the amphipod -2arathemiSto gaudichaudi ,
occur ver rarely.
During the period spent in the fattening-grounds the thickness
of the blubber layer increases by from 15'; . : to 2 5:), ensuring a
great increase in the oil yield when the whales are processed.
The females attain sexual maturity at an average body length
of 23.8 metres, and the males at 22.6 metres. The peak of mating
occurs in winter, apparently in May and June. Gestation lasts for
ten months and three-Quarters (on an average, from the end of May
until the middle of the following Avril). The most intensive growth
of the embryo takes place during the last five months of pregnancy:
its length increases from 1.5 to 7.0 metres, and its weight from 20
kg to 2,500 kg. During . the last two months of pregnancy its weight
increases by more than two tons, from 420 kg to 2,500 kg. An embryo
7.46 metres iï lew;th weighed 2,800 kg.
The calf is fed for more than six months on milk containing
from 35 to 50: of fat. During the whole lactation period the calf •
doubles ii length, atainig a length ofe 15-16 metres or more. A
ferlale with a calf 12-1i; meures long ras observed in February at 70 o S.
The transition period of mixed feeding (on milk and crustaceans) is
not 7-,roomeed.
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