the Gulf of
Maine from March through June, off Newfoundland as early as June but
increasing to August, and entering Davis Straits and beyond in
substantial numbers in midsummer to late summer. There is some evidence
that the animals venturing farthest north are the largest individuals of
the species. Movements of the population(s) southward have usually begun
by October, though some fin whales sometimes remain in the northern seas
sufficiently long to become trapped in the ice and killed.

During winter the range of fin whales spreads out from the advancing ice
southward, reaching at least to the coast of Florida, into the Gulf of
Mexico, and to the Greater Antilles, though fin whales are not at all
common in tropical waters. During the winter many fin whales move into
offshore waters. Northward migrations probably begin in midspring.

Fin whales may be found in Cape Cod waters all year long.

There may be two or possibly three separate stocks of fin whales in the
western North Atlantic, one more northern cold-adapted stock and another
more southern stock. The ranges of the two stocks appear to overlap,
such that the winter range of the northern stock probably becomes the
spring and summer range of the more southern stock. The third stock may
consist of an isolated population in the northern Gulf of Mexico.

Stranded Specimens

Stranded fin whales may be most readily identified by 1) the
yellowish-white coloration of the right front baleen and the right white
lower lip; 2) the numerous baleen plates (262-473 in number); 3) the
numerous ventral grooves (56-100 in number) extending to the navel and
beyond (Table 2); and 4) the broad, flat sharply pointed head with only
a single head ridge.

[Illustration: Figure 15.--The heads of fin whales surfacing to breathe
off Japan and in the northern North Atlantic (inset). When they can be
approached from the right side, fin whales can be positively
distinguished from the other large balaenopterine species by the white
coloration of the right lower lip and the flat, narrow head. Note also
the single central head ridge. (_Photos by Japanese Whales Research
Institute, courtesy of H. Omura, and K. C. Balcomb_ (_inset_).)]

[Illustration: Figure 16.--A small group of fin whales off British
Columbia. Fin whales may be found in groups of up to six or seven
individuals and these groups may congregate in feeding grounds. (_Photo
by G. C. Pike, courtesy of I. MacAskie._)]

[Illu