few feet down and leaving a series of tracks or
swirls on the surface as they move their tail flukes. When they are
feeding in this manner, sei whales may exhibit a highly regular blowing
and diving pattern over long periods of time.

Sei whales usually travel in groups of from two to five individuals,
though they may concentrate in large numbers on the feeding grounds.

In the northern portion of their range, sei whales feed on copepods.
Throughout the remainder of the range, however, their food is more
varied and also includes krill and a variety of small schooling fishes.
The species derived its common name, in fact, from its frequent
occurrence with or near sei fish.

May Be Confused With

The sei whale's smaller size and decidedly taller, more falcate dorsal
fin located well more than one-third forward from the tail should
prevent confusion with the blue whale. At a distance, however, sei
whales are difficult to distinguish from either fin whales or Bryde's
whales. The primary clues for distinguishing them from fins are the
differences in swimming, blowing, and diving characteristics tabularized
in detail on p. 26 and the asymmetrical coloration of the fin whale.

Sei whales may be distinguished from Bryde's whales only upon close
examination. The dorsal fin of Bryde's whales is small, to 18 inches
(45.7 cm), sharply pointed, and often worn on the rear margin. If close
examination is possible, the sei whale will be seen to have only a
single head ridge. Bryde's whales have two additional ridges--one on
each side of the main ridge. Bryde's whales are primarily fish feeders
and their diving behavior more closely resembles that of a fin whale
than that of a sei whale. (See p. 37).

Distribution

The distribution and migrations of the sei whale during most of the year
are rather poorly known. The species is known to avoid the colder
regions near the pack ice and to range from Iceland south to the
northeast Venezuelan coast and the northeast and southwest Gulf of
Mexico. There are also records from Cuba and the Virgin Islands. Along
the northeast United States and eastern Canadian coasts, where most
research on sei whales has been conducted, the species migrates from New
England through the Blanford, Nova Scotia area in June and July, is
found in small numbers off eastern Newfoundland in August and September
(abundant in Placentia Bay, Newfoundland in August), and continues
northward to the Davis Straits in