he bottom picture. The top photo illustrates
the origin of the Newfoundland common name "jumper." (_Photos by K. C.
Balcomb (top) and H. E. Winn (bottom)._)]

[Illustration: Figure 139.--The highly distinctive pattern of the
Atlantic white-sided dolphins is clearly visible in this animal stranded
in Scotland. Even if the color pattern has faded, however, this species
should be easy to identify. The 30-40 teeth in each of the upper and
lower jaws permit distinction from the white-beaked dolphins, which have
only about 22-28 per side in each jaw. (_Photos by B. Tullock, courtesy
of A. S. Clarke._)]

WHITE-BEAKED DOLPHIN (T)

_Lagenorhynchus albirostris_ Gray 1846

Other Common Names

White-beaked porpoise, squidhound (Newfoundland).

Description

White-beaked dolphins reach a maximum overall length of about 10 feet
(3.1 m). The body is robust in form with a tall, uniformly dark-gray
dorsal fin, and a short but distinct beak which, as the common name
implies, is often light gray to white above and below, at least in
European waters. The beak of animals in the western Atlantic populations
is less frequently white. The back and sides are basically dark gray to
black, and the belly is white to light gray.

Swimming white-beaked dolphins can be most readily identified by the two
areas of pale coloration on the sides, one in front of and another below
and behind the dorsal fin. These areas are clearly visible from a ship
or aircraft as the animals roll at the surface.

Natural History Notes

White-beaked dolphins may sometimes occur in herds of up to 1,500
individuals. Like their cousins, the Atlantic white-sided dolphins, they
do not commonly ride the bow waves of vessels.

White-beaked dolphins feed on squid, octopus, cod, herring, capelin, and
sometimes on benthic crustaceans.

May Be Confused With

In their northerly range white-beaked dolphins are likely to be confused
with only the Atlantic white-sided dolphins. The most distinctive
features of white-beaked dolphins are 1) the two areas of paleness
described above, 2) the prominent, dark gray dorsal fin, and sometimes
3) the white beak. Other features by which the two species may be
distinguished in the brief encounters typical at sea are tabularized on
p. 127.

Distribution

White-beaked dolphins are the more northerly of the two species of
_Lagenorhynchus_ in the western North Atlantic. They are found from Cape
Cod, Mass., north to w