ve been rarely encountered at
sea. Therefore statements of range are usually limited to inferences
from locations of strandings, and information on appearance and habits
of the species in the wild is almost totally lacking.

The infrequent encounters with beaked whales at sea may result from such
factors as 1) a low inconspicuous blow, 2) avoidance of ships, and/or 3)
distribution in small groups in offshore areas well outside the normal
boating lanes.

The following descriptions will aid primarily in identifying stranded
specimens. Though subtle differences in ranges, color patterns, and
dorsal fin shapes and positions may be helpful in narrowing the choices
of living animals, the species will continue to be extremely difficult
to distinguish from one another in the brief encounters typical at sea
until additional data are collected.

The beaked whales have the following characteristics in common: 1) two
small creases forming a V-shape on the throat, 2) the absence of a
conspicuous notch on the rear margin of the tail flukes (some specimens
have a slight indentation), and 3) the absence of functional teeth in
all except adult males. Adult males have a single pair of teeth in the
lower jaw, the position and description of which help to identify the
species. The teeth of females are not functional and only rarely emerge
from the gums. Therefore, if a stranded animal is an adult male, its
species can be determined by the position and description of the teeth.
For example, in _Mesoplodon mirus_, the teeth are located near the tip
of the lower jaw; in _M. europaeus_, they are located about a third of
the way from the tip of the snout to the corner of the mouth; in _M.
bidens_, they are nearly half way from the tip of the snout to corner
of the mouth; and in M. densirostris, they are located in large
prominences near the back of the mouth.

If the animal is a female or an immature male, however, museum
preparation and examination might be required before the species can be
positively determined. The following four sections summarize characters
of western North Atlantic beaked whales.

[Illustration: Figure 76.--An unidentified beaked whale from the
mid-Pacific. Note the marks along the back, presumably tooth rakes,
consisting of scratches that are paired and close together. A beaked
whale in the western North Atlantic marked in this manner would be a
northern bottlenosed whale (p. 67), a goosebeaked whale (p. 70), or a