may be
brown or black) with fine white bristles on each upper jaw. (_Photo from
Santa Barbara, Calif. by S. Anderson._)]

NORTHERN BOTTLENOSED WHALE (T)

_Hyperoodon ampullatus_ (Forster 1770)

Other Common Names

None known.

Description

Northern bottlenosed whales reach a length of 32 feet (9.8 m) and are
robust in form. They are characterized by a bulbous forehead, which is
more pronounced on larger animals and most distinctive in adult males,
and by the dolphinlike beak displayed in animals of all sizes and ages,
which is sometimes visible as the animals surface steeply to breathe.

The blowhole is located in an indented area behind the bulbous forehead,
and the blow emanating from it projects upward or slightly forward to a
height of up to 6 feet (1.8 m), is bushy and is visible from a
considerable distance under low wind conditions. The dorsal fin, located
two-thirds of the way back on the back, reaches at least 12 inches (30.5
cm) in height and is distinctly falcate. The dorsal fin may be visible
from a distance of several hundred meters.

Northern bottlenosed whales are usually brownish in color, though the
markings change with age. Smaller animals are a uniform chocolate brown.
Larger animals retain the chocolate brown color on the back but are
often lighter on the sides and the belly and often have irregular
patches or blotches of grayish-white coloration on the back and sides.
Extremely large animals, presumably older males, often have a white
head. The flippers and the undersides of the flukes are uniformly brown
in color.

Natural History Notes

Northern bottlenosed whales often form tightly packed groups of up to 10
or more animals. This species holds the anecdotal record for the longest
dives, having been reported by early whalers to remain submerged over 2
h. They are probably deep divers, feeding primarily on squid (though
they may take fishes as well), and they rarely go in water shallower
than 100 fathoms (183 m).

After a long dive, northern bottlenosed whales will sometimes remain on
the surface for 10 min or more, blowing at regular intervals before
making another dive. After the last blow of a series or when the animals
are startled by a boat, they may show the tail flukes as they begin to
dive. The flukes are not notched on the rear margin.

Northern bottlenosed whales have been observed to show curiosity about
boats, coming to them from a considerable distance. They