Translation 2783

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The southward mij^iations apparently take place in the
opposite sequence.
The principal wintering-grounds of the American herd are
located near Lower California (:qainly between 30 0 A? and 22" i^`) and
off the coast of Mexico from 23° I' to 18° N. S:nall groups of wintering
hump-back whales have-beer_ observed near the Revilla Gigedo
Isla.nd^-. A very few cases of wintering hump-back whales have been
recorded in the waters adjacent to the eastern Aleutian Islands.
Migration northward begins in 1111arch, and the first ht^^np-back
whales are observeô. in the Gulf of Alaska in the middle of April;
later their number increases, especially in ï,`ia.y and June. By the
end of Julie and the beginning of July hump-back whales are also to
be seen in the western Aleutian Islands.
The chief summer habitat of hump-back whales embraces the
waters north of the 50th parallel from 170° W to 145° W.
In the Bering Sea notable concentrations have been observed
only between the Aleutian Islands and -Nunivàk Island, and in the
-vicinity of the Pribylof Islands and Cape Navarin; also in the Gulf
of Anadyr and north of St. Lawrence Island, where they appear in
July and stay until 'September. When they entered the C1lukcnz Sea
they were generally seen near Cape Serdtse-Kamen'.
Among crustaceans they eat Euphausiacea, some P+Iysida.e, and
also Copepoda and Amphipoda. They readily eat fishes t_l.at travel
in shoals: herring, capelin, smelt, walleye pollock, cod, navaga,
sand-eels, anchovies, various Hexagr.amidae, chum salmon, and pink
salmon. Their stomachs have been found to contain from 600 to 800
kg of fish.
Their methods of procuring food vary. When t.liey are pursuing
fishes the whales' movements are jerky and abrupt. At such
times a half-turn of the body round its axis is very noticeable.
Trrhen they are feeding on c.emersal organisms hump-back whales dive
straight down, so that their flukes ap:)ear above the surface.
I'ale Intmp-ba.ck whales of the American herd attain sexual
maturity, on an average, at a body length of 71.7 metres, and fema.les
at 12.0 metres- These whales mate from October to April, but also
168
may mate (ap;?a:L-ently in individual casés) in surzlner on their feeding--`rounds.
Gestation lasts for less than a year. At first the