DOLPHIN OR PORPOISE
There is still considerable controversy over the correct usage of the terms dolphin and porpoise. As mentioned in the preceding section, common names of any species may vary from locale to locale and even from individual to individual. Some persons argue for the use of the term porpoise for all small cetaceans. Others insist on the term dolphin. Still others either randomly use the terms or call members of the family Delphinidae dolphins and members of the family Phocoenidae porpoises. The evidence supporting any one of these positions is confusing at best and no usage of terms appears to be without problems. We see no wholly satisfactory resolution to the problem at this time. For all these reasons, we have little desire to defend our decision to follow the last of these practices in this guide, referring to all members of the family Delphinidae for which the term dolphin or porpoise appears in the common name as dolphins, and to the one member of the family Phocoenidae represented in the western North Atlantic, Phocoena phocoena, as the harbor porpoise. Although all cetaceans may be regarded as whales, the term "whale" most commonly applies to the larger animals. For all species treated, other common names by which they may be known are also listed.
Detailed treatment of the relative merits of the various terminologies is inappropriate here. Furthermore, it is our opinion that the usage of the terms dolphin, porpoise, and whale as part of the common names of cetaceans is largely a matter of personal preference.
ORGANIZATION OF THE GUIDE
The differences between baleen and toothed whales are easy enough to see in animals washed up on the beach or maintained in a tank at a zoo or aquarium. But since an animal at sea can seldom be examined that closely, its most obvious characteristics may be its overall size, the presence or absence of a dorsal fin, its prominent coloration or markings, its general behavior, or its swimming, blowing, and diving characteristics. For that reason, regardless of their scientific relationships, all the whales, dolphins, and the one porpoise covered in the main text of this guide are divided into three groups. Those over 40 feet (12.2 m) long are discussed in the section on [Large Whales], those from 13 to 40 feet (4.0 to 12.2 m) in the [Medium-Sized Whale], and those less than 13 feet (4.0 m) in the [Small Whales, Dolphins, and Porpoise (with a dorsal fin)]. There are no small whales, dolphins, or porpoises in this region without a dorsal fin. Each section is further divided into those animals with a dorsal fin and those without. From that point, animals likely to be confused in the field are grouped together and the important differences between them are discussed.
The synoptic accounts of the species are followed by five appendices: [Appendix A] discusses and illustrates man-made and applied tags and natural markings on cetaceans and their importance in studies of natural history. [Appendix B] discusses the data which are most important to record in observations of cetaceans at sea, gives examples, and provides blank sighting forms. [Appendix C] discusses possible causes of cetacean strandings and the manner in which stranded animals should be handled and adds a key and tables to aid in identifying stranded cetaceans. [Appendix D] provides guidelines for collecting data on stranded cetaceans and provides forms and specific instructions for taking standard measurements. [Appendix E] lists institutions to be contacted in the event of a cetacean stranding or for information.
A [bibliography] of useful references on cetaceans in general and cetaceans of this region in particular and a [directory to species accounts] are included.
