with special assistance by
William E. Schevill[4] and Melba C. Caldwell[2]
[1] Biomedical Division, Undersea Sciences Department, Naval Undersea Center, San Diego, CA 92132.
[2] Biocommunication and Marine Mammal Research Facility, C. V. Whitney Marine Research Laboratory of the University of Florida, St. Augustine, FL 32084.
[3] Graduate School of Oceanography, University of Rhode Island, Kingston, RI 02881.
[4] Woods Hole Oceanographic Institution, Woods Hole, MA 02543 and Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138.
ABSTRACT
This field guide is designed to permit observers to identify the cetaceans (whales, dolphins, and porpoises) they see in the western North Atlantic, including the Caribbean Sea, the Gulf of Mexico, and the coastal waters of the United States and Canada. The animals described are grouped not by scientific relationships but by similarities in appearance in the field. Photographs of the animals in their natural environment are the main aids to identification.
A dichotomized key is provided to aid in identification of stranded cetaceans and appendices describe how and to whom to report data on live and dead cetaceans.
INTRODUCTION
All whales, dolphins, and porpoises belong to an order or major scientific group called the Cetacea by scientists. They are all mammals (air-breathing animals which have hair in at least some stage of their development, maintain a constant body temperature, bear their young alive, and nurse them for a while) which have undergone extensive changes in body form (anatomy) and function (physiology) to cope with a life spent entirely in the water. The breathing aperture(s), called a blowhole or blowholes, has (have) migrated to the top of the head to facilitate breathing while swimming; the forward appendages have become flippers; the hind appendages have nearly disappeared, they remain only as small traces of bone deeply imbedded in the muscles. Propulsion is provided by fibrous, horizontally flattened tail flukes.