David Keller Caldwell

“ The single most distinctive feature of Atlantic white-sided dolphins is an elongated oval zone of white and yellowish white along the sides from just below the dorsal fin to the area above the anus. These patches of lighter coloration, clearly demarcated from each other and from the surrounding coloration, are frequently visible simultaneously with the dorsal fin as the animals roll at the surface to breathe. Even alone this feature permits positive identification of the species. The dorsal fin is often part gray, part black. The beak is all black. ”

“ Despite variability in behavior by members of the same species from one encounter to the next, an observer can greatly increase the reliability of his identification by forming the habit of working systematically through a set of characteristics for the species rather than depending on any single characteristic. ”

“ There are three species of large whales without a dorsal fin in the western North Atlantic Ocean. Two of these, the bowhead or Greenland whale, and its more widely distributed close relative the right whale, are baleen whales. The third, the sperm whale, is a toothed whale. The first two have relatively smooth backs without even a trace of a dorsal fin. The sperm whale has a humplike low, thick, dorsal ridge, which, from certain views, particularly when the animal is humping up to begin a dive, may be clearly visible and look like a fin. ”

“ The dorsal fin, like that of the Atlantic pilot whale, is one of the species' most distinctive characteristics. It is low in profile, has a long base, and is set far forward on the animal's back.
Short-finned pilot whales are all black on the back sides and most of the belly with an anchor-shaped patch of gray on the chin and a gray area of varying extent and intensity on the belly. These areas are less vivid and extensive than those on Atlantic pilot whales. Younger animals are lighter, often medium gray. ”

“ With a Key to the Identification of Stranded Cetaceans of the Western North Atlantic Stranded Animals
As we discussed briefly in the introduction to this guide, whales, dolphins, and porpoises sometimes "strand" or "beach" themselves, individually or in entire herds, for a complex of still incompletely understood reasons. Though the reasons suggested for these strandings appear almost as numerous as the strandings themselves, two tenable generalizations have recently been proposed.
Strandings of lone individuals usually involve an animal which is sick or injured. ”

“ The flippers and the trailing edge of the flukes are darker than the rest of the body.
As they age, the Atlantic spotted dolphins develop grayish-white spots, first low on the sides, spreading upward. During this stage, the cape becomes less distinct, and dark spotting begins to develop on the belly, the spots increasing in number with increasing age. In adult animals, the belly is often extensively covered with dark blotches but never becomes completely black. The lips may be white, and the beak is characteristically tipped with white, a feature which may aid in identification at sea. ”

“ The body is robust in form with a tall, uniformly dark-gray dorsal fin, and a short but distinct beak which, as the common name implies, is often light gray to white above and below, at least in European waters. The beak of animals in the western Atlantic populations is less frequently white. The back and sides are basically dark gray to black, and the belly is white to light gray. ”

“ False killer whales are a social form and may occur in herds of up to at least 100 individuals. They often jump clear of the water and frequently ride the bow waves of vessels. They are the only "blackfish" which are known to do so. False killer whales feed primarily on squid and large fishes and are notorious for their habit of stealing fish from the lines of fishermen. The large prominent teeth may be visible on a swimming animal. ”

“ Some individuals, especially the larger animals, are found as far offshore as the edge of the continental shelf. Atlantic bottlenosed dolphins sometimes ride the surf. Individuals may jump clear of the water as high as 15-20 feet (4.6-6.1 m) , a behavior on which aquarium shows have capitalized.
Members of this species are the dolphins most commonly maintained in captivity at zoos, aquariums, marine parks, and research institutions. For that reason, they are perhaps more familiar to the general public than any other species of porpoise, dolphin, or whale. ”

“ Minke whales are distributed in the polar, temperate, and tropical waters of the western North Atlantic. They are found from the pack ice south to at least Anguilla, Lesser Antilles, and the eastern Gulf of Mexico, though they appear to be most abundant in temperate waters north of the latitude of New York and are infrequently reported from tropical waters. At least some of the population migrates to the northern portions of their range in spring and back south in autumn. They often approach close to shore and enter river mouths, inlets, and estuaries. ”

“ The buoyancy of the water will reduce the stress to the animal and will help to keep it cool and prevent overheating—a real danger to stranded cetaceans.
Whether or not the animal can be floated, care should be taken to protect it from sunburn, drying out, and overheating. If it is afloat, exposed parts should be frequently splashed down. If it is high and dry, it should be covered with damp cloth, particularly on the dorsal fin, flippers, and flukes, and the body and the terrain should be frequently watered to prevent the animal from overheating in the areas in contact with the sand or rock. ”

“ The rationale of these programs was that since oceanographers, commercial and sport fishermen, naval personnel, commercial seamen, pleasure boaters, and coastal aircraft pilots together canvas large areas of the oceans which scientists specializing in whales (cetologists) have time and funds to survey only occasionally, training those persons in species identification and asking them to report their sightings back to central data centers could help scientists more clearly understand distribution, migration, and seasonal variations in abundance of cetacean species. ”

“ 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. ”

“ 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 ”

“ Females are much smaller, rarely exceeding 38 feet (11.6 m) .
A sperm whale is among the easiest of whales to identify at sea even when comparatively little of the animal is visible. It has a huge head, which comprises from a fourth to a third of the animal's total length. (The proportion is considerably higher for males than for females.) The blunted "squarish" snout, which may project up to 5 feet (1.5 m) beyond the tip of the lower jaw, houses a large reservoir containing a high-quality oil called spermaceti. ”

“ As the animals age, their color darkens to almost black with distinctive regions of grayish white on the belly and chest. The body of older adults is cream white or silver gray, particularly on the head, with numerous scars, presumably from encounters with other grampus and perhaps with the squid, which are one of the species' major food items.
The flippers, dorsal fin, and tail flukes usually remain dark even in adults. ”

“ Because of their tall, falcate dorsal fin, dwarf sperm whales may be confused at a distance with any of the small dolphin species. Their all-black or dark steel-gray coloration and the blunted head increase the likelihood that they can be confused with pygmy killer whales or many-toothed blackfish. They will have to be examined at close range before they can be distinguished. ”

“ Today in addition to the more abundant populations of the Bering, Beaufort, and Chukchi seas and the Sea of Okhotsk, there are populations off eastern Greenland and in Davis Straits, Baffin Bay, James Bay, and the adjacent waters. Within these ranges, bowhead whales move southward in front of the advancing ice floes and may be expected near the southern limits of their range from September or October through the early spring months. Populations in the western North Atlantic appear to be increasing slowly. ”

“ Throat grooves are short grooves found on the throat of beaked whales, sperm whales, and dwarf sperm whales. Ventral grooves are long grooves found only on balaenopterine whales. Ventral grooves should be counted between the flippers.
It is difficult to overstress the importance of data from stranded cetaceans. For some species, the only data available have come from stranded individuals. By carefully gleaning from each specimen all the data that can be collected, you will make a valuable addition to the body of knowledge on these elusive animals. ”

“ The body of the species is all black except for a blaze of gray on the belly between the flippers. This blaze varies from barely visible to light grayish white similar to but generally fainter than that of pilot whales. The body is long and slender, and the head is narrow and gently tapered from the area of the blowhole forward. ”

“ Migrations of the species are probably closely tied to movements of their food supply. They annually arrive on the coast of New England with the tuna. Along the Canadian coasts, where distribution and migrations have been described in some detail, killer whales appear to move inshore in spring and summer. Many arrive off the east coast of Newfoundland in June, the Strait of Belle Isle in June and July, and slightly later along the Labrador coast and Arctic waters. ”

“ During this time they may be examined carefully and their identifying characteristics seen.
Though euphausiids may be an important food for this species in limited areas, Bryde's whales often feed on schooling fish (including pilchards, anchovies, herring, and mackerel) . This food preference is reflected in the diving behavior of the species. Bryde's whales are not "skimmer" feeders; they are deeper divers. When they surface to breathe, they often rise more steeply to the surface, exposing much of the head, roll the body sharply, and hump up the tail stock before beginning another dive. ”