certain whales as shown by logbook records
of American whaleships. Zoologica (N.Y.) 19:1-50.

TRUE, F. W.

1889. Contributions to the natural history of the cetaceans, a
review of the family Delphinidae. Bull. U.S. Natl. Mus. 36:1-192.

WALKER, E. P.

1964. Mammals of the world. The Johns Hopkins Press, Baltimore, p.
1083-1145. [Cetaceans. There is also a second, revised edition of
this work, and a third, revised edition is planned.]

APPENDIX A

TAGS ON WHALES, DOLPHINS, AND PORPOISES

Field studies of cetaceans are very difficult. First, it is extremely
hard to be positive that an individual or a group of animals is the same
from one encounter to the next. This means that it is nearly impossible
to determine, for example, whether herds of animals are resident in an
area or only seasonal visitors. Without information of this kind,
determinations vital to population management, such as sizes of
populations and natural ranges, are impossible to make.

Secondly, as we frequently point out in this guide, individual cetaceans
are usually visible to a surface observer only during the brief moments
when they break the air-water interface to breathe. The majority of
their vital activities (e.g., feeding, reproduction, communication,
establishing and maintaining position within the herd, and defending
against natural enemies) take place primarily below the surface, well
out of view to a surface observer.

In recent years, in an attempt to overcome some of these problems,
scientists have been placing markers on various species of cetaceans and
monitoring their movements. The following brief summary of major methods
of tagging cetaceans is provided to acquaint the reader with markers he
may expect to see in the western North Atlantic.

Static Tags

Since their development in the mid-1920's, numerous Discovery marks
(small stainless steel projectiles with identifying information stamped
on them) have been shot into commercially valuable species by means of a
shotgun. The recovery of these marks from whales subsequently killed in
the whaling industry has provided valuable information on the movement
patterns and on basic aspects of the growth and development of harvested
species of whales. Discovery marks are limited, however, because they
are not visible in a living animal. Reduction in whaling activities will
bring about a significant reduction in their use.

More recent t