Chapter III: Part 3

When they are seen at relatively close range, minke whales can be readily distinguished from the other rorquals that have relatively tall, falcate dorsal fins (fin, sei, and Bryde's whales) by their considerably smaller size and by their distinctive white band on each flipper.

At a distance, however, positive identification may be difficult. Minke whales have a small, low, inconspicuous blow. Like sei whales, they frequently expose the dorsal fin simultaneously with the blow, but minke whales hump the tail stock much higher when beginning a long dive--more like fin whales.

From a distance, minke whales might also be mistaken for northern bottlenosed whales (or any of several other beaked whales with a similar dorsal fin). They can be distinguished by the differences in head shape, body color and markings, and behavior, detailed on p. 67.

Distribution

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.

Minke whales arrive along the Canadian coast in May or June. Some migrate as far north as Hudson Strait, where they remain until the freeze in October, November, or December. By December the majority of the population has begun to move to the south, although some animals remain behind so long as to become entrapped in the ice and die. Spring and summer concentrations along the Canadian coast correspond to concentrations of capelin, cod, and herring. Southern concentrations, also corresponding with concentrations of herring, extend farther offshore at least to the edges of the Grand Bank. Minke whales also summer off the south coast of western Greenland, which they probably reach from waters southwest of Iceland. Minke whales also occur in deep pelagic waters.

Stranded Specimens

Stranded minke whales can be most readily identified by: 1) their small size (to just over 30 feet [9.1 m]); 2) the transverse white bands on the flippers; 3) the yellowish-white baleen plates (up to half the posteriormost plates may be brown or black), 300-325 per side in number and having fine white bristles (the plates are up to 4.75 inches [12 cm] wide at the base and up to 8 inches [20.3 cm] long); and 4) by the 50-70 thin ventral grooves, ending well before the navel, often just even with the flippers.

NORTHERN BOTTLENOSED WHALE (T)

_Hyperoodon ampullatus_ (Forster 1770)

Other Common Names

None known.

Description

Northern bottlenosed whales reach a length of 32 feet (9.8 m) and are robust in form. They are characterized by a bulbous forehead, which is more pronounced on larger animals and most distinctive in adult males, and by the dolphinlike beak displayed in animals of all sizes and ages, which is sometimes visible as the animals surface steeply to breathe.

The blowhole is located in an indented area behind the bulbous forehead, and the blow emanating from it projects upward or slightly forward to a height of up to 6 feet (1.8 m), is bushy and is visible from a considerable distance under low wind conditions. The dorsal fin, located two-thirds of the way back on the back, reaches at least 12 inches (30.5 cm) in height and is distinctly falcate. The dorsal fin may be visible from a distance of several hundred meters.

Northern bottlenosed whales are usually brownish in color, though the markings change with age. Smaller animals are a uniform chocolate brown. Larger animals retain the chocolate brown color on the back but are often lighter on the sides and the belly and often have irregular patches or blotches of grayish-white coloration on the back and sides. Extremely large animals, presumably older males, often have a white head. The flippers and the undersides of the flukes are uniformly brown in color.

Natural History Notes

Northern bottlenosed whales often form tightly packed groups of up to 10 or more animals. This species holds the anecdotal record for the longest dives, having been reported by early whalers to remain submerged over 2 h. They are probably deep divers, feeding primarily on squid (though they may take fishes as well), and they rarely go in water shallower than 100 fathoms (183 m).

After a long dive, northern bottlenosed whales will sometimes remain on the surface for 10 min or more, blowing at regular intervals before making another dive. After the last blow of a series or when the animals are startled by a boat, they may show the tail flukes as they begin to dive. The flukes are not notched on the rear margin.

Northern bottlenosed whales have been observed to show curiosity about boats, coming to them from a considerable distance. They have also been observed to "lobtail," raising the tail flukes above the water and slapping them against the surface, and to jump clear of the water.

In the late 19th century, after stocks of bowhead whales were severely reduced by overwhaling, northern bottlenosed whales became a prime target of arctic whalers. They were sought because in addition to whale oil produced from the body blubber, the forehead of the species yielded quantities of spermaceti like that obtained from sperm whales.

May Be Confused With

Northern bottlenosed whales have a northerly and deep-water distribution. Within their range, they may be confused at a distance with minke whales, with sperm whales, or perhaps with North Sea beaked whales.

Minke whales (p. 63) have a falcate dorsal fin located in approximately the same position as that of the northern bottlenosed whale. However, minke whales have a flathead in front of their two blow holes and are black to dark gray on the back.

Sperm whales (p. 57) have a squarish head that may somewhat resemble that of an adult male northern bottlenosed whale. However, there are numerous characteristics which will permit these species to be distinguished even from a distance:

NORTHERN
BOTTLENOSED WHALE SPERM WHALE

BLOW

Low and bushy; projects Low and bushy, projects
upward from indentation on obliquely forward from left
top of head. side of head; usually less
than 8 feet (2.4 m).

COLORATION

Lighter brown; adults splotched Brownish gray; body appears
with grayish white; wrinkled.
body smooth.

FLUKES

Rarely notched; seldom raised Notched; raised on long dive.
on long dive.

HEAD

Tapering in younger animals; Squarish, long, all black;
bulbous in adults; beakless.
white in older animals; beaked.

A further aid to distinguishing northern bottlenosed and sperm whales at sea is the fact that the sperm whales that are found in areas where northern bottlenosed whales are encountered are usually older, larger males from 40 to 60 feet (12.2 to 18.3 m) long. Northern bottlenosed whales do not exceed 32 feet (9.8 m).

Northern bottlenosed whales may also be confused with the poorly known North Sea beaked whale (p. 82). When they can be examined at close range, however, northern bottlenosed whales should be distinguishable on the basis of the distinctly bulbous forehead.

Distribution

In the western North Atlantic, northern bottlenosed whales are restricted to Arctic and north temperate waters, where they most commonly occur in offshore areas. They have been reported from Davis Straits and the entrance to Hudson Strait, the Gully southeast of Sable Island, and as far south as Narragansett Bay, R.I.

In the spring and summer they concentrate near the northern limits of their range, occasionally visiting deep channels of the Gulf of St. Lawrence and eastern Newfoundland in summer. During these seasons they may extend to the edge of the pack ice.

In the fall and winter the bulk of the population migrates southward. Many probably winter in the Labrador Sea while others move farther southward and farther offshore.

Stranded Specimens

Like the beaked whales discussed on p. 70 through 83, the northern bottlenosed whales have no notch in the tail flukes, have two throat grooves forming a V-shape on the chin, and have only two teeth in the lower jaw, with those teeth emerged from the gums only in adult males. These teeth may have sometimes fallen out of older males, but the tooth sockets should still be visible in the gums.

NOTE: Some specimens--both male and female--will be found to have a series of vestigial teeth the size of toothpicks in the upper and/or lower jaws. Similar vestigial teeth, 5-40 in number, sometimes occur in goosebeaked whales (p. 70). Further when they are prepared for museum collections, the lower jaws of adult northern bottlenosed whales may be found to contain a second pair of teeth just behind the first.

Northern bottlenosed whales may be distinguished from the remainder of the beaked whale family, however, by the extremely robust body, by the bulbous forehead, which is more extensively developed in larger animals, particularly males, and by the pronounced dolphinlike beak.

GOOSEBEAKED WHALE (T)

_Ziphius cavirostris_ G. Cuvier 1823

Other Common Names

Ziphius, Cuvier's beaked whale, grampus (St. Vincent) (see also p. 96).

Description

Goosebeaked whales reach a length of 23 feet (7 m). Females are slightly larger than males of the same age. Calves are probably less than about 6 feet (1.8 m) at birth. The head is small relative to the body length and, when viewed laterally, is slightly concaved or scooped on the upper margin. The cleft of the mouth is small, smaller than in any other species of beaked whales. The beak is indistinct in larger individuals. There is a distinct indentation on the back behind the head. Two teeth are found at the tip of the lower jaw of adult males only.

The dorsal fin is relatively tall and distinct, to at least 15 inches (38.1 cm), smoothly falcate, and located well behind the midpoint of the back. The blowhole is located far forward on the top of the head. The blow, which may project slightly forward and slightly off to the left, is usually low and inconspicuous. Though the first blow after a long dive may be more distinct, even it is rarely visible even under good wind conditions for more than a few hundred yards.

Descriptions of the color pattern vary. Individuals may be dark rust brown, slate gray, or fawn colored on the back and generally lighter on the belly. Some appear dark in both regions, still others--particularly youngsters--appear lighter gray or tan on the belly. The body is frequently covered with white or cream-colored blotches (particularly on the belly). The tail flukes are dark on the bottom. The head is frequently paler in color. Old males have a distinct white head and are frequently extensively scarred.

Natural History Notes

Goosebeaked whales frequently occur in groups of from 10 to as many as 25 individuals. They have been reported to jump clear of the water. They are presumably deep divers and are known to stay down for more than 30 min. When they begin a deep dive, they often raise their tail flukes above the surface and dive nearly vertically. Goosebeaked whales feed primarily on squid.

May Be Confused With

So little is known of the external appearance and behavior of the living beaked whales at sea that all the species may easily be confused.

Goosebeaked whales are larger than all other beaked whale species with the exception of the northern bottlenosed whale. Upon close examination they may be distinguished from the northern bottlenosed whale by the lighter coloration of the head, reaching an extreme in the white head of adult males. (See p. 67 and Fig. 75.)

Distribution

As with other species of beaked whales seldom encountered or at least seldom positively identified at sea, the distribution of goosebeaked whales is poorly known and must be constructed from records of stranded specimens. Such records, often involving sick individuals that may have washed ashore from considerable distances, may give an inaccurate picture of normal ranges.

In general, stranding reports suggest that goosebeaked whales are sparsely but widely distributed in nonpolar latitudes. They appear to be primarily tropical in distribution, though they venture into temperate areas in summer. They have been reported from Massachusetts and Rhode Island south to Florida and thence to the islands of the West Indies. They are frequently stranded along the Florida coast and are not an uncommon species in the extant whale fishery of the Antillean Islands. The fact that goosebeaked whales strand more frequently than other beaked whales may reflect either a greater abundance or a greater tendency to approach close to shore.

They are probably primarily an offshore species.

Stranded Specimens

To be positively identified, stranded goosebeaked whales in an advanced state of decomposition may require museum preparation and examination of the skull and teeth. Fresh specimens may be tentatively identified by the characters illustrated in the figures.

OTHER BEAKED WHALES (T)

_Mesoplodon_ spp.

Other Common Names

Grampus (St. Vincent) (see also p. 96).

Description

In addition to the northern bottlenosed whale (p. 67) and the goosebeaked whale (p. 70), four other species of beaked whales have been reported from the western North Atlantic. All four species are known primarily from stranded specimens and have been rarely encountered at sea. Therefore statements of range are usually limited to inferences from locations of strandings, and information on appearance and habits of the species in the wild is almost totally lacking.

The infrequent encounters with beaked whales at sea may result from such factors as 1) a low inconspicuous blow, 2) avoidance of ships, and/or 3) distribution in small groups in offshore areas well outside the normal boating lanes.

The following descriptions will aid primarily in identifying stranded specimens. 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.

The beaked whales have the following characteristics in common: 1) two small creases forming a V-shape on the throat, 2) the absence of a conspicuous notch on the rear margin of the tail flukes (some specimens have a slight indentation), and 3) the absence of functional teeth in all except adult males. 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; in _M. europaeus_, they are located about a third of the way from the tip of the snout to the corner of the mouth; in _M. bidens_, they are nearly half way from the tip of the snout to corner of the mouth; and in M. densirostris, they are located in large prominences near the back of the mouth.

If the animal is a female or an immature male, however, museum preparation and examination might be required before the species can be positively determined. The following four sections summarize characters of western North Atlantic beaked whales.

(Because so little is known of beaked whales every encounter should be recorded in as much detail as possible.)]

TRUE'S BEAKED WHALE (T)

_Mesoplodon minis_ True 1913

Other Common Names

None known.

Description

True's beaked whales reach a length of at least 16 feet (4.9 m) long. They are chunky in midbody and narrow rapidly towards the tail, closely resembling goosebeaked whales (p. 70). In overall body shape, the head is small with a slight indentation in the area of the blowhole, a slight bulge to the forehead, and a pronounced beak. The flippers are small (from one-fourteenth to one-tenth the body length). The dorsal fin is small, slightly falcate, located in the latter third of the back, and followed by a pronounced ridge on the tail stock. The flukes, which sometimes contain a very slight notch, are broad (to almost one-fifth the body length).

True's beaked whales are dull black to dark gray on the back, lighter slate gray on the sides, and white on the belly. The body is frequently covered with light colored spots or splotches and bears numerous pairs of scratch marks, presumably tooth rakes (Fig. 76).

The flippers are all black and are attached in the dark coloration of the animal's side. The flukes are dark above and below.

May Be Confused With

True's beaked whales are most likely to be confused with goosebeaked whales (p. 70) but may also be confused with any of the other beaked whales species (p. 74 and Fig. 78).

Distribution

True's beaked whales appear to be primarily temperate in distribution. They have been reported from Cape Breton Island, Nova Scotia south as far as Flagler Beach in Florida. Northernmost records are for summer months.

The range of True's beaked whales overlaps with that of the Antillean beaked whale but is more northerly.

Stranded Specimens

The teeth of adult male True's beaked whales may be visible near the tip of the lower jaw, a characteristic shared with the goosebeaked whale (p. 70) and the northern bottlenosed whale (p. 67). Both these other species reach substantially greater maximum lengths than True's beaked whales, however, and should be readily distinguishable by this and the number of other highly distinctive characteristics of each species.

Females and subadult males may be confused with any of the beaked whales species (p. 74 and Fig. 78).

ANTILLEAN BEAKED WHALE (T)

_Mesoplodon europaeus_ (Gervais 1855) (equals _M. gervaisi_ [Deslongchamps])

Other Common Names

Gulfstream beaked whale, Gervais' beaked whale.

Description

Antillean beaked whales reach a length of at least 22 feet (6.7 m). They are slender in form and appear somewhat laterally compressed (i.e., taller than they are wide). The head is extremely small and tapers rapidly to a narrow beak. The flippers are small (to about one-twelfth the body length) with their origin well down on the sides of the body. The dorsal fin is small, located behind the midpoint of the back, and variable in shape from falcate to triangular. The flukes are less than one-fifth the body length and are not notched.

Antillean beaked whales are dark grayish black on the back and sides, slightly lighter on the abdomen. The flukes are dark gray above and below.

Natural History Notes

Antillean beaked whales are probably primarily oceanic in distribution and are known to feed on squid.

May Be Confused With

Antillean beaked whales may be confused with any of the other beaked whales though they are larger than all except the northern bottlenosed whale (p. 67) and the goosebeaked whale (p. 70).

Distribution

Antillean beaked whales have been reported stranded from the latitude of Long Island, N.Y. south to Florida, thence into the Caribbean and the Gulf of Mexico.

Stranded Specimens

The teeth of Antillean beaked whales are located at the suture of the mandible, about one-third of the way from the tip of the snout to the corner of the mouth (Fig. 78).

DENSE-BEAKED WHALE (T)

_Mesoplodon densirostris_ (Blainville in Desmarest 1817)

Other Common Names

None known.

Description

Dense-beaked whales reach a length of at least 17 feet (5.2 m). The body is distinctly spindle-shaped. The head, the contour of which is the most distinctive characteristic of this species, is marked by a prominent rise, located near the angle of the gape on each side. This rise, which bears the teeth, gives a peculiar high, arching contour to the mouth (p. 84), particularly in adult males.

The flippers are small (one-eleventh to one-tenth the body length) and have their origin in the lighter color of the lower sides. The dorsal fin varies from small and triangular to nearly falcate and pointed on the tip. It is located behind the midpoint of the back. The flukes are from one-sixth to one-fifth the body length, are seldom notched, and occasionally even bulge slightly backwards near the center of the rear margin.

Dense-beaked whales are black or charcoal gray on the back, slightly lighter on the abdomen. They are somewhat blotched with grayish white and are often extensively scratched or scarred. The flippers are lighter than the back. The flukes are dark above, light below.

Natural History Notes

From stomach contents of stranded animals dense-beaked whales are known to feed on squid.

May Be Confused With

Adult male dense-beaked whales can be separated from the other beaked whales by the high, arching contour to the corners of the mouth. If there is no adult male in the group, however, dense-beaked whales may be confused with any of the other beaked whales species.

Distribution

Dense-beaked whales have been reported from Peggys Cove, Nova Scotia south to Florida. From all accounts, this species appears widely but sparsely distributed in warm temperate seas.

Stranded Specimens

Adults of this species should be distinguishable by the highly distinctive contour of the mouth. The teeth, located in the high rise of the mouth, are oriented slightly backwards.

NORTH SEA BEAKED WHALE (T)

_Mesoplodon bidens_ (Sowerby 1804)

Other Common Names

Sowerby's beaked whale.

Description

North Sea beaked whales reach a length of at least 16.5 feet (5 m). The body is distinctly spindle-shaped, but apparently more robust near midbody than that of the dense-beaked whale. The head is characterized by a pronounced bulge in front of the blowhole, a slightly concave forehead, and a moderate to long beak. The flippers are relatively long (one-eighth to one-ninth the body length). The dorsal fin is reportedly tall and variable in shape from triangular to slightly falcate and is located just behind the midpoint of the back. The flukes are not notched but are sometimes quite concave on the rear margin.

Adult North Sea beaked whales are dark charcoal gray on the back with white spots overall. Young animals are also dark charcoal gray on the back but are lighter on the belly and are unspotted. The flukes of adults are dark above and below. Those of young are dark above, lighter below.

Natural History Notes

North Sea beaked whales are known to feed on squid.

May Be Confused With

North Sea beaked whales are the most northerly species of beaked whales. No other species is very likely to be encountered in the same area.

Distribution

North Sea beaked whales have been reported in the offshore waters from the latitude of New England north perhaps to the pack ice. Individuals are occasionally drawn to the coasts of Newfoundland in summer, presumably by concentrations of squid, a known food item.

Stranded Specimens

The teeth of North Sea beaked whales are located about midway between the tip of the snout and the corner of the mouth. Except for this characteristic and their northerly distribution, however, this species might easily be confused with any other of the beaked whales species.

) stranded in Hjertuika in 1957. (_Photo courtesy of A. Jonsgard._)]

KILLER WHALE (T)

_Orcinus orca_ (Linnaeus 1758)

Other Common Names

Blackfish (see also pilot whales, p. 91 and 94), sword fish (Canada), grampus (see p. 96), whitefish (St. Vincent), Espladon (Quebec).

Description

Killer whales are the largest member of the dolphin family. Adult males reach a length of at least 30 feet (9.1 m) and are robust in form. One specimen of 31 feet (9.5 m) was recorded for the western North Pacific. Females are considerably smaller and less stocky. Newborn are approximately 7-8 feet (2.1-2.4 m) long. Killer whales have large paddle-shaped flippers.

The most distinctive field character of the species is the dorsal fin. In adult males it is extremely erect and may be as much as 6 feet (1.8 m) tall. Though the fin of females and immature males is less than 3 feet (0.9 m) tall, it is nonetheless taller even in these animals than in any other cetacean species and is distinctly falcate and pointed on the tip.

Killer whales are basically black with an extensive region of white on the undersides extending from the lower jaw to the anal region with a branch extending onto the flanks behind the dorsal fin. There is an oval white patch on the side of the head just above and behind the eye. In newborn and very young calves, these regions may be tan to lemon yellow in color. Most animals have a light-gray saddle marking just behind the dorsal fin. The undersides of the flukes are usually white. Both all-black and all-white animals have been reported.

Natural History Notes

Killer whales travel in groups of from a few to 25 or 30 individuals, though herds of 150 have been reported. Males appear polygamous, and females and young may form groups separate from young bachelors and bulls.

Killer whales are extremely fast swimmers, capable of reaching top speeds of 25 knots or more, and have been reported "porpoising" and breaching. Individuals and entire groups have also been reported "spy-hopping," or "pitchpoling," behaviors which consist of hanging vertically in the water with the head and much of the body (to just behind the flippers) exposed above the surface.

Killer whales feed on squid, fishes, sea turtles, seabirds, and marine mammals.

Controversy still continues over whether or not killer whales pose a threat to man. Documented attacks of killer whales on boats are rare and have usually been provoked (i.e., harpooning or attempts to capture). Only two uncertain instances of attacks in the wild have been reported, but all divers and mariners should be cautioned that this powerful animal is perfectly capable of doing tremendous damage and should not be provoked.

May Be Confused With

Because of its very distinctive dorsal fin, body shape, and coloration, the killer whale is not likely to be confused with any other whale when it can be examined at close range or when an adult male is present in the group. Pods of females and immature animals, however, may be confused with false killer whales or with grampus. The killer whales may be distinguished from false killers by the following differences:

KILLER WHALE FALSE KILLER WHALE

BODY SHAPE

Chunky. Slender.

BODY COLOR

Black with white on belly, All black with some gray on
flank, and head. belly.

DORSAL FIN

Very tall and erect in adult Shorter, slender, strongly
males; tall and slightly back falcate.
curved in female.

HEAD SHAPE

Broad, rounded. Tapered, slender.

FLIPPER SHAPE

Paddle-shaped. Moderately long with
characteristic hump near
middle on forward margin.

LENGTH

To at least 30 feet (9.1 m). To at least 18 feet (5.5 m).

Furthermore, false killer whales are the only "blackfish" which are known to ride the bow wave of a ship.

Grampus have a tall dorsal fin (15 inches [38.1 cm]) which is very similar in appearance to that of adult female and juvenile killer whales. But grampus have much lighter coloration, from slate gray to nearly all white, and larger animals are covered with numerous scratches. Upon closer examination they can be further distinguished from killer whales by a crease in the front of the head dividing the melon into two distinct sections. Grampus are considerably smaller, to about 13 feet (4 m) maximum length.

Distribution

In the western North Atlantic killer whales have been reported from the polar pack ice south to Florida and St. Vincent, Lesser Antilles, and into the Gulf of Mexico at least as far as Texas, though they are far more common in the cooler waters from about New Jersey north. Throughout their range, killer whales seem to prefer coastal areas and often enter shallow bays, estuaries, and river mouths in search of food.

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. They are found around the loose ice in April, presumably feeding on harp seals, _Pagophilus groenlandicus_, and hooded seals, _Cystophora cristata_, and are frequent in the St. Lawrence estuary in spring and autumn following the movements of the white whales. The northward movements in spring also coincide with migrations of balaenopterine whales, which have also been reported among the food items. Killer whales may remain in arctic or subarctic waters until driven out by new forming ice in October and November. Though the migration has not been as thoroughly described, killer whales apparently begin shifting southwards in autumn.

Stranded Specimens

Stranded killer whales should be readily identifiable by the robust body, the distinctive body markings, and in larger animals the tall dorsal fin. Killer whales have from 10 to 12 large, prominent teeth on each side of the upper and lower jaws.

FALSE KILLER WHALE (T)

_Pseudorca crassidens_ (Owen 1846)

Other Common Names

Mongoose (St. Vincent).

Description

False killer whales in the western North Atlantic reach a length of at least 18 feet (5.5 m). Males are slightly larger than females. Calves from 5 to 7 feet (1.5 to 2.1 m) may be seen at any time throughout the year.

The dorsal fin, located just behind the midpoint of the back, is from 7 to 16 inches (17.8 to 40.6 cm) tall, falcate, and variable to sharply pointed on the tip. The flippers are characterized by a broad hump on the front margin near the middle, a characteristic which is diagnostic for the species.

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.

Natural History Notes

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.

May Be Confused With

False killer whales may be confused with killer whales, pilot whales, or the smaller, poorly known pygmy killer whale (p. 138) and many-toothed blackfish (p. 142).

The characteristics distinguishing the species from the killer whale are tabularized on p. 84; its differences from the pilot whales are summarized on p. 92.

At sea, false killer whales are distinguishable from the other two species primarily by their larger size and differences in coloration. False killer whales are up to 18 feet (5.5 m) in length. Pygmy killer whales and many-toothed blackfish reach only 8-9 feet (2.4-2.7 m) in length. Pygmy killer whales have an extensive region of white on the belly which may extend onto the sides and both pygmy killer whales and many-toothed blackfish have a distinctive white region on the lips, usually lacking or indistinct on false killer whales.

Neither of the smaller species of blackfish has been reported to ride bow waves.

Distribution

False killer whales are widely distributed in the pelagic tropical, subtropical, and warm temperate waters of the western North Atlantic. They have been reported from off Maryland south along the mainland coasts of North America, in the Gulf of Mexico from Cuba and the Lesser Antilles, and from the southeast Caribbean Sea. The species has been reported from Venezuela.

Stranded Specimens

Stranded false killer whales can be positively identified by: 1) the large size (to 18 feet [5.5 m]); 2) the slender body tapering rapidly to a long slender head; 3) the markedly long mouth, with from 8 to 11 large, conspicuous teeth in each side of each jaw recalling those of the killer whale, but circular and not, as in killer whales, elliptical; 4) the unusually shaped flipper bulging conspicuously on the forward margin.

For comparison with "blackfish" of similar size (the pilot whales) see p. 92 and 94.

False killer whales do not appear to occur frequently in coastal waters, sandy bays, or estuaries, though entire herds have stranded in such areas. Records from throughout the range suggest that the species has an oceanic distribution.

off northeastern Florida by H. E. Winn._)]

ATLANTIC PILOT WHALE (T)

_Globicephala melaena_ (Traill 1809)

Other Common Names

Northern pilot whale, long-finned pilot whale, pothead, blackfish, calling whale, caa'ing whale.

Description

Male Atlantic pilot whales reach an average length of at least 20 feet (6.2 m). Females are slightly smaller, probably not exceeding 18 feet (5.5 m). Young are 5-7 feet (1.5-2.1 m) at birth.

The head is thick and bulbous, a characteristic which reaches an extreme in the development of the head of adult males (prompting the common name "pothead"). The flippers are long (to one-fifth of the body length, or more) and sickle-shaped. The tail is dorsally thickened just in front of the flukes.

The dorsal fin of this species is one of its most distinctive characteristics. It is low in profile, has a long base, is set far forward on the animal's back, and is falcate to "flaglike" in appearance. The dorsal fin of adult males reportedly has a thicker leading edge and a rounder form than that of the female.

Atlantic pilot whales are black on the back and sides (prompting the common name "blackfish") but have an anchor-shaped patch of grayish white on the chin and a gray area on the belly, both of which are variable in extent and intensity. Some larger animals have a gray saddle behind the dorsal fin, though this zone of color is found more frequently in short-finned pilot whales. Young animals are often a lighter medium gray.

Natural History Notes

Atlantic pilot whales may occur in herds of 200 animals or more, though herds of 50 or fewer (4-6) are more common. They are sometimes found in association with Atlantic white-sided dolphins.

Pilot whales are sometimes found hanging vertically in the water with the head and part of the back out of the water in what has been called "spy-hopping" or "pitchpoling." Individuals frequently lobtail. Pilot whales infrequently breach, a behavior which is usually confined to younger animals. They do not ride bow waves.

Atlantic pilot whales feed primarily on squid but also take cod and other fishes. A Pacific pilot whale, a closely related species, was found by radio telemetric studies to be capable of diving to 2,000 feet (609.6 m).

Atlantic pilot whales were formerly the object of an active shore fishery off Newfoundland (1950-1971). In addition, entire herds and, less frequently, individuals are sometimes stranded.

May Be Confused With

Atlantic pilot whales are most likely to be confused with false killer whales, with which they share the waters from off Virginia to those off Maryland. The two species may be distinguished by the following characteristics:

ATLANTIC PILOT WHALE FALSE KILLER WHALE

SHAPE OF HEAD

Thick and often squarish in Slender, gently tapering
larger animals. mouth long.

SHAPE OF BODY

Robust. Long and slender.

DORSAL FIN

Broad-based and falcate. Slender, tall, falcate, and
pointed on tip.

COLORATION

Black with gray saddle Mostly black with gray blaze
sometimes evident behind of variable extent and
dorsal fin and gray region intensity on belly between
on chin and belly. flippers.

BEHAVIOR

Will not ride bow waves; May ride bow waves, often
seldom breaches. "porpoises" and breaches.

RANGE

Temperate waters from at Temperate seas from at least
least North Carolina north. Maryland south.

In the extreme southern portion of their range, Atlantic pilot whales may be confused with short-finned pilot whales with which they have only a limited seasonal common range. Characters distinguishing these species are subtle and may not be adequate to permit them to be distinguished at sea. For purposes of this guide it is generally that pilot whales living north of lat. 38 deg.N (Virginia coast) are Atlantic pilot whales and those living south of lat. 38 deg.N are short-finned pilot whales.

Distribution

Atlantic pilot whales, the northernmost of the two pilot whales species, are found in winter from the Grand Banks south as far as North Carolina and in summer from Iceland and Greenland south to the New Jersey coast. Winter concentrations of pilot whales may be found off the Newfoundland coast and near Cape Cod, Mass. Atlantic pilot whales are distributed both in coastal waters and in deep waters off the continental shelf.

Stranded Specimens

As discussed above, individuals and groups of pilot whales frequently strand themselves for still incompletely understood reasons. They may be identified as pilot whales primarily by: 1) the robust body and bulbous head, which is often squarish in adult animals, and 2) the broad-based, falcate dorsal fin located far forward on the back. Accurate determination of the pilot whale species involved in the stranding may require museum preparation of the skull and detailed examination of its characteristics. Preliminary identification may be made, however, based on the following:

ATLANTIC PILOT WHALE SHORT-FINNED PILOT WHALE

FLIPPER LENGTH

To one-fifth body length, To one-sixth body length, or
or more. less.

NORMAL RANGE

From North Carolina north. From North Carolina south.

TEETH

8-11 per row. 7-9 per row.

SHORT-FINNED PILOT WHALE (T)

_Globicephala macrorhynchus_ Gray 1846

Other Common Names

Blackfish (see also p. 84, 91, and 94).

Description

Male short-finned pilot whales of the western North Atlantic reach lengths of at least 17.5 feet (5.3 m). Females are reportedly slightly smaller than males (recorded only to 15.5 feet [4.7 m]).

The head, somewhat like that of the Atlantic pilot whales (p. 91), is thick and bulbous, a characteristic which reaches its extreme in the development of a flattened or squarish appearance to the front of the head in mature males (see Fig. 101). In very old males the melon may overhang the mouth up to several inches. The flippers are shorter than those of the other pilot whale species of the western North Atlantic (thus the common name short-finned pilot whale), reaching only one-sixth of the body length or less. The tail is dorsoventrally thickened just in front of the flukes.

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.

Natural History Notes

Short-finned pilot whales are known to occur in groups of 60 animals or more, though smaller groups are more common. They have been reported pitchpoling (spy-hopping), lobtailing, and--rarely--breaching.

Short-finned pilot whales feed on squid and fish.

May Be Confused With

In the tropical portion of their range, short-finned pilot whales may be confused with pygmy killer whales (p. 138) and many-toothed blackfish (p. 142). They may be distinguished from both species primarily by their distinctive dorsal fin and the bulbous-to-squarish head. Both pygmy killer whales and many-toothed blackfish have dorsal fins, which are more falcate, slender, and pointed on the tip, and have longer, slenderer heads.

Throughout their range short-finned pilot whales may be confused with false killer whales. The two species may be distinguished by the same differences which distinguish Atlantic pilot whales from false killer whales (p. 91).

In the extreme northern portion of their range, short-finned pilot whales may be confused with Atlantic pilot whales. The two species may be distinguished by differences itemized on p. 93.

Distribution

Though short-finned pilot whales are known from Delaware Bay, their normal range appears to extend from Bermuda and Cape Hatteras (Virginia in summer) south to the Venezuelan coast. They have been reported for the Gulf of Mexico, the Caribbean, and the islands of the West Indies.

Stranded Specimens

Stranded short-finned pilot whales may be confused with any of the species itemized under living animals. They may be identified as pilot whales primarily by the robust body and bulbous head, often squarish in adult animals, and the broad-based, falcate dorsal fin located well forward on the animal's back. Accurate determination of the pilot whale species involved may require museum preparation of the skull and detailed examination of its characteristics. Preliminary identification may be made, however, on the basis of the following:

ATLANTIC PILOT WHALE SHORT-FINNED PILOT WHALE

DISTRIBUTION

Primarily North Carolina Primarily North Carolina
north. south.

FLIPPERS

To one-fifth body length, To less than one-sixth body
or more. length.

TEETH
8-11 per row. 7-9 per row.

GRAMPUS (T)

_Grampus griseus_ (G. Cuvier 1812)

Other Common Names

Risso's dolphin, gray grampus, white-headed grampus, mottled grampus, Risso's porpoise, hard knocks (St. Vincent), white blackfish (Cape Cod).

Description

Grampus reach a maximum length of about 13 feet (4 m). The body is robust, particularly in front of the dorsal fin, and lacks a distinct beak. The head is somewhat bulbous and is marked on the front by a V-shaped crease with the point downwards, which divides the melon into two parts. The flippers are long and pointed on the tips. The dorsal fin, located at about the midpoint of the body, is tall, to 15 inches (38.1 cm) or more, and distinctly falcate. The body narrows rapidly behind the dorsal fin and the tail stock is quite narrow. The flukes are broad, concaved on the rear margin, and deeply notched.

The bodies of grampus are a uniform light gray at birth. 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.

Natural History Notes

Grampus are found in herds of up to several hundred individuals and may be seen "porpoising" (leaping from the water) as they surface to breathe, and breaching. They sometimes ride the bow waves of a boat.

Grampus feed on fish and squid.

May Be Confused With

From a distance grampus are most easily confused with Atlantic bottlenosed dolphins. They may be most readily distinguished by the following differences:

ATLANTIC BOTTLENOSED
GRAMPUS DOLPHIN

SIZE

To 13 feet (4 m). Rarely to 12 feet (3.7 m);
usually less than 10 feet
(3.1 m).

BODY COLOR

Young are uniform light Dark gray on body; lighter
gray; older animals dark gray on sides; white or pink
with grayish regions on on belly; may appear brownish
chest and belly; very in water.
old animals white and
scarred.

DORSAL FIN

To 15 inches (38.1 cm); To 12 inches (30.5 cm) less
sharply falcate; pointed sharply falcate; pointed on
on tip. tip.

HEAD COLOR AND SHAPE

Blunted and creased on Uniformly brownish to gray
front; frequently all distinctly bottlenosed.
white in larger animals.

MARKINGS

Very often extensively Less frequently scratched
scarred. and scarred.

Distribution

Grampus are known to be distributed in temperate and tropical seas from at least eastern Newfoundland, south at least to St. Vincent, Lesser Antilles, and in the eastern and northern Gulf of Mexico. The species may not be as rare as the paucity of records suggests. Though they have been seen in Buzzards Bay on several occasions, grampus generally have an oceanic range and, along the Atlantic coast of North America, may be distributed from the Gulf Stream seaward, outside the theater of normal boating traffic.

Stranded Specimens

Stranded grampus are most readily identifiable by 1) the presence of only seven, or fewer, teeth in each side of the lower jaw (many of those teeth may have dropped out in older animals and remaining teeth may be extensively worn) and the absence of teeth in the upper jaw; 2) the presence of a distinct crease or bifurcation in the melon on the extreme front of the head; 3) the presence of numerous scratches and scars all over the body; and 4) the tall, slender, sharply falcate dorsal fin which may be more than 15 inches (38.1 cm) tall.

Medium-sized Whales Without a Dorsal Fin

BELUGA (T)

_Delphinapterus leucas_ (Pallas 1776)

Other Common Names

White porpoise, white whale, belukha, sea canary, marsouin blanc (Quebec).

Description

Belugas reach a maximum overall length of about 16 feet (4.9 m). Males are slightly larger than females. In the western North Atlantic they have been found to grow to greatest lengths in oceanic environments near the southern extremities of their ranges, though they are found in far greater abundance in estuarine areas of the Arctic. Belugas have extremely robust bodies tapering to a distinct "neck" region and a very small head relative to body size.

They do not have a dorsal fin. Instead, along the back just behind the midpoint there is a narrow ridge notched laterally to form a series of small bumps. These ridges may be clearly visible on a swimming animal.

Newborn belugas are brown. As they age, they gradually lighten through slate gray, and by their sixth or seventh year have assumed the all-white coloration characteristic of adult animals.

Natural History Notes

Belugas feed on a variety of fishes (including cod and capelin), on squid, and on a variety of benthic crustaceans.

They are frequently found in shallow bays and river mouths, where the young are born, and occasionally ascend rivers.

May Be Confused With

Because of their limited distribution, all-white coloration and lack of a dorsal fin, belugas are unlikely to be confused with any other species of cetacean.

Distribution

Belugas have been reported from the Arctic Circle south as far as eastern Connecticut, typically in estuarine habitats, though they do range into oceanic regions. They are most abundant from the north shore of the Gulf of St. Lawrence northward. They remain near the Arctic Circle and in Hudson Bay to northern Greenland during winter, undertaking migrations to the south in autumn, straggling to the Maritime Provinces and as far as Connecticut. Belugas are regularly seen in the St. Lawrence and Saguenay rivers throughout late spring and summer. Return migrations to the north take place in spring.

A small population in the estuary of St. Lawrence is resident throughout the year.

Stranded Specimens

Stranded belugas are unlikely to be confused with any other species of cetaceans. The all-white coloration, the robust body shape with a rather small head and a distinct neck region, and the presence of 8-11 teeth in each of the upper jaws and 8-9 in each of the lower jaws permit positive identification.

NARWHAL (T)

_Monodon monoceros_ Linnaeus 1758

Other Common Names

Unicorn whale (historical name not currently in use).

Description

The narwhal, also known as the unicorn whale because of the long tusk found on adult males, is one of two medium-sized whales found in the Arctic waters of the northwestern Atlantic. They reach a maximum length of from 15 to 16 feet (4.6 to 4.9 m) excluding the tusk. Newborn calves are approximately 5 feet (1.5 m) long. Narwhals have small rounded heads and a small mouth. Like the other medium-sized whale in the same region, the beluga or white whale, the narwhal has no dorsal fin. Instead, it has a series of bumps, approximately 2 inches (5.1 cm) high along the midline of the back in the half nearest the tail. The ridge created by these bumps may be readily seen on a swimming animal.

The basic coloration of the species changes slightly with age. Young animals are uniformly dark bluish gray on the back but rapidly begin to develop the numerous leopardlike spots on the back and sides characteristic of adults. Those spots rarely extend onto the belly even in old animals.

Narwhals have only two teeth. In the females, these teeth rarely emerge from the gums. In males, one and sometimes both of those teeth grow out the front of the snout, spiraling in a left-hand or sinistral direction, and may reach a length of 9 feet (2.7 m). One or two tusks may also be exposed, however, in females.

Natural History Notes

The function of the tusk in male narwhals is unknown, but it was this feature of the animal that earned it the name "unicorn whale" and resulted in its extensive hunting by whalers. During their annual migrations narwhals may congregate but are commonly found in groups of 10 or fewer during the rest of the year.

Narwhals feed on a variety of organisms, including cod, rockfish, flounder, and crabs, but their diet consists primarily of squid.

Distribution

Narwhals are found in the high arctic seas of the western North Atlantic, primarily in Lancaster Sound and its fringes. It has been noted that they are found in isolated pockets within that range and are not, like the beluga, widely distributed.

Narwhals make annual migrations in response to the movement of the ice. During the fall as the ice begins to form, the whales migrate to the south, sometimes reaching the Labrador coast. In the spring they return to the pack ice.

May Be Confused With

Narwhals are so different in coloration from the only medium-sized cetacean which shares its range and habitat--the beluga--that the two are highly unlikely to be confused. Belugas are usually all white or light slate gray in color, while narwhals are very much darker, ranging from bluish gray to brownish, and are often covered with light leopardlike spots. Furthermore, the body of the beluga is more robust.

Further, swimming narwhals frequently buck their heads up to breathe, a behavior which makes the tusk of adult males visible and permits positive identification.

Stranded Specimens

Stranded narwhals should be easily identifiable by the distinctive coloration and the unique characteristics of the teeth. In adults, one or two of the teeth may develop into the long, left-hand spiraling tusk, shown in Figures 112 and 114. Immature animals have no teeth which are emerged.

Small Whales, Dolphins, and Porpoises With a Dorsal Fin

ATLANTIC SPOTTED DOLPHIN (T)

_Stenella plagiodon_ (Cope 1866)

Other Common Names

Spotter, Gulf Stream spotted dolphin, spotted porpoise, long-snouted dolphin.[11]

[Footnote 11: See also p. 110. The common name "long-snouted dolphin" was once widely used for this species. It is now more frequently used for _Stenella longirostris_, also known as the spinner dolphin.]

Description

Atlantic spotted dolphins reach a maximum adult length of 7.5, perhaps 8 feet (2.3 to 2.4 m). They are generally more robust in body shape than the other species of Stenella, closely resembling Atlantic bottlenosed dolphins in that regard, though the Atlantic spotted dolphins tend to be more slender.

The dorsal fin is distinctly back-curved and pointed on the tip, also closely resembling that of the Atlantic bottlenosed dolphin.

As the common name suggests, the Atlantic spotted dolphins are marked dorsally with numerous grayish-white spots on a darker background and ventrally with dark spots on a lighter background, though the extent of the spotting and the additional details of coloration change with age.

Immature animals lack spots completely. They are dark gray or purplish gray on the back, becoming lighter gray on the sides and white on the belly. The cape along the back is distinctly separated from the lighter gray coloration of the sides. 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 Atlantic spotted dolphins have a spinal blaze and a light line which extends from the flipper to the eye.

Natural History Notes

Little is known of the natural history of the Atlantic spotted dolphins. The species occurs in herds of up to several hundred individuals, though groups of 50 or fewer (6-10) are more common. They are often seen jumping clear of the water and habitually ride the bow wave of moving vessels. As they do, the distinct cape or band of purplish gray on the back of younger animals and the spotting pattern of older animals may be visible.

Atlantic spotted dolphins feed primarily on squid but may also take carangid fishes, small eels, herring, or anchovies.

May Be confused With

Atlantic spotted dolphins, particularly young animals, may be easily confused with Atlantic bottlenosed dolphins because of the similarities in color pattern and general body shape. However, the Atlantic spotted dolphins have considerable purplish gray in their background colors and the Atlantic bottlenosed dolphins are more dark gray to brownish gray. This along with considerable differences in the overall sizes of the two species should permit positive identification. In general, the key differences between spotted and bottlenosed dolphins are as follows:

ATLANTIC SPOTTED ATLANTIC BOTTLENOSED
DOLPHIN DOLPHIN

MAXIMUM SIZE

To 7.5-8 feet (2.3-2.4 m). To 8-10 feet (2.4-3.1 m)
inshore, to as much as 12 feet
(3.7 m) offshore.

BODY COLOR