Translation 2783

i'he
..... 265^
0
first Dryde' s whales appear in the Kyushu region (33 N,
1?0° E; in July, but almost two-thirds of the kill is made in Sep-
It is possible that in that region (the northeastern part
tember.
of the ^ast China. Sea) these whales belong to another population --
their length is approximately one metre less than that of whales
of the Bonin Islands 01 roup
As soon as t^,,.e water temperature begins to fall, in September
or October, the Bryde's whales leave the Sanriku region a.nd go to
warmer southern waters, i,: ith a water temperature of 2no-29o C.
During the migration period the whales are observed to be
segregated according to sex. In the Oshima region, in years with
f^^.vourable temperature conditions, females are observed more often
than males. In the Sanriku region the numbers of females increase
froniMay to August, and decrease in September, but never fall below
50%; sometimes the numbers fall abruptly in the-middle of summer
(in July) and rise again by the end of September.
In the Sanriku region Bryde's whales feed principally on
'uphausie.cea, but mackerel and cephalopods are also
anchovies and ^,
found in their stomachs. Year Oshima t_zese whales feed in different
seasons on anchovies and Eupha:asiacea.
In the Bonin Islands region male Bryde's whales attain
sexual maturity at a body lc.ngth of 11.9 metr.es,, when the pair of
testes weighs 1.5 kg; the females beco!:ie sexually mature at a body
length of 12.2 metres. The age of suc.11 whales is generally five
yea.rs.
iiionths...
The matinv se-.ason is prolonged, usually lasting for several
Gestation appears to last for about a year; new-born calves
are about four metres in length.
In the vicinitJ of the Ja_^anese islands, males from 10.6 to
13.5 metres long and females from 10.G to 14.4 inetrès long were aged
from 1.5 to 16.5 yea,°s and from 2.5 to 14 years respectivelY>
The parasites and diseases of -,Rytt Bryqe's whales have not
been investigatee..
The hunting of B.ryde's whales is chiefly concentrated around
The anima.ls
117e11e
ara hunted most intensively
from i;a J 1 to June
Japan.
52 y Tlh^.n a.l+: ost 700 of tiic;n
10 1951 ar:.d from i':a^r 1 to Julie 20, 11
, ^
were killec; .
coastal sta:i:i o.le at Cish:i.mcl and in tcic: Sariril;.u a^°ea. take
..'r?e