Mammals of North America
Page 18
SAMBAR Rusa unicolor 1.9–2.8m, 25–30 cm, 109–260kg
A large dark brown ungulate with stout antlers and a white rump and undertail. Has a bald, rounded glandular area on the middle of the throat. Large antlers are stout and rugose, with three prominent tines. In season, males have a mane of hair on the neck and forequarters. Crepuscular and nocturnal. Native to India and Southeast Asia, now established in small numbers in Texas, California (Obispo County), Florida (St. Vincent Island), and perhaps other areas. Prefers wooded areas.
BARBARY SHEEP Ammotragus lervia 1.4–1.8m, 14–25 cm, 100–145kg; 45–65kg
A large exotic sheep with long, curved horns and long hair on the throat, chest, and front of the legs. Native to the Sahara Desert of North Africa, introduced into California, New Mexico, and Texas (mostly Panhandle region). Tail is long and tufted. Upperparts are rufous or grayish brown with a blackish mid-dorsal line. Flanks, inner surface of legs and belly are whitish; chest is colored like the sides. Yellowish horns darken with age. Inhabits dry, rough, barren, and waterless habitat, where it likely competes with native Bighorn Sheep.
PLATE 99
LARGE WHALES WITHOUT DORSAL FINS
GRAY WHALE Eschrichtius robustus 11.1–14.3m; 11.7–15.0m, 15,700–33,800kg
Unique with mottled gray color and low rounded hump in place of dorsal fin. Narrow triangular head is covered with barnacles and whale lice. Mouthline is straight or slightly arched. Small flippers and large flukes are frequently marked with white from lice and scars. Top of tail stock is covered with bumpy knuckles. Active in water, often swims in shallows. Stirs up mud when feeding from sea floor. Strains food with baleen. Low heart-or V-shaped blow. Migrates along west coast between Arctic summer waters and Baja winter waters.
BOWHEAD Balaena mysticetus 14–17m; 16–18m, 75,000–100,000kg
Large, smooth-skinned, black whale with no dorsal fin. Indentation behind blowhole divides profile of triangular head from rotund body. Head and back produce two humps above water in profile. Chin is white with variable black spotting; some also have white around tail stock. Large fluke and paddle-shaped flippers are black and unmarked; fluke is shaped like that of the North Atlantic Right Whale. A record of 3m–long Bowhead baleen is largest of any whale. Blow is high and V-shaped. Feeds alone or in groups. Can break ice to breathe. A rare and Endangered species. Closely tied to pack ice in Arctic waters.
NORTH ATLANTIC RIGHT WHALE Eubalaena glacialis 11–18m, 60,000–100,000kg
Large black whale with large callosities and no dorsal fin. Smooth slope of back is different from Bowhead’s double-hump profile. Flukes and wedge-shaped flippers are black with limited mottling. Body is black except for variable amounts of white on belly. Blow is V-shaped. This slow, inquisitive whale was the “right” whale to hunt and was nearly driven to extinction. Modern recovery is slowed by mortality from fishing gear entanglement and collisions with ships. Still highly endangered, only about 300 animals survive (red area on map).
NORTH PACIFIC RIGHT WHALE Eubalaena japonica 11–18m, 22,000–107,000kg
Like the North Atlantic Right Whale in appearance, but recently recognized as a distinct species based on genetic differences. Occasionally reported from Alaska to Baja, more common in North and West Pacific parts of its range. Calving grounds unknown. Critically Endangered with as few as 100 animals left in the eastern Pacific (yellow area on map of North Atlantic Right Whale).
SPERM WHALE Physeter catodon 11–18.3m, 11,00057,000kg; 8.3–12.5m, 6800–24,000kg.
Unique large whale with square head, undersized lower jaw, and wrinkled skin. Body color varies from dark gray to light brown, rarely white like Moby Dick. Skin around mouth usually white. Male is larger, with a protruding spermaceti organ projecting beyond the skull. Angular hump is followed by a keeled tail stock topped by bumpy knuckles. Has stubby flippers and a large triangular fluke. Single blowhole at front of head sends a bushy blow forward and to the left. Typically dives to 300m in search of squid and octopi, may reach 3000m. Usually dives to avoid boats. An endangered species. Swims in groups of ca. 20 animals in deep waters; moves north in summer and south in winter.
PLATE 100
ENORMOUS WHALES WITH DORSAL FINS
HUMPBACK WHALE Megaptera novaeangliae 14–17m, 25,000–45,000kg
Dark whale with remarkably long, knobby flippers. Top of flippers are dark in the Pacific race and white in the Atlantic race. Head is knobbed with tubercles; projection under chin may grow with age. Dorsal fin varies from low and stubby to high and curved. Pattern of white on flukes and shape, size, and scarring of dorsal fin allows identification of individual whales; end of tail is serrated. Widely spaced throat grooves help distend mouth for filter feeding. Blow is low and bushy. Most active and acrobatic of the large whales. Unique feeding technique involves the release of columns of bubbles that encircle schools of fish and contain them so the whales can lunge into the center of the bubble net and engulf large numbers at once. Mating and calving occur in tropical and subtropical waters in winter. They feed extensively in summer in productive cold high-latitude waters, and do not eat during the winter breeding season. This Endangered species migrates along both coasts between summer Arctic waters and winter southern waters, where it is among the most familiar of the great whales.
BLUE WHALE Balaenoptera musculus 22–28m, 64,000–195,000kg
The world’s largest animal, and the largest animal ever to exist, they are mottled blue with a U-shaped head and tiny dorsal fin. Larger than Fin Whale, with a blue mottled back (not smooth gray), a more rounded head, and a less prominent dorsal fin. Shape of dorsal fin varies from round to pointed. Belly may be light blue, white, or yellow. Long slender flippers tipped in white. Thick, smooth tail stock. Females are larger than males, and may weigh as much as 30–40 African elephants. Animals are larger in the southern hemisphere. High, slender blow. Mating and calving must occur well offshore. Calves are 6–7m at birth in fall and winter, and they nurse for 7–8 months to reach 16m. The nursing young put on 90kg per day. Sexual maturity is reached at about 5 years, when the animals are about 20m long. A rare and Endangered species. Migrates along both coasts between summer Arctic waters and winter southern waters.
FIN WHALE Balaenoptera physalus 17.7–22m; 18.3–24m, 45,000–70,000kg
The world’s second largest animal is a large whale with smooth gray skin and a V-shaped head. Undersides of belly, flippers, and fluke are white. Rarely shows fluke. Shape of pointed dorsal fin is variable. Top of tail stock is ridged. Asymmetric lower jaw and baleen are dark on left and white on right. This head color, and the unique chevron pattern behind the head allow individual identification. Blow is high and cone-shaped. Migrate from summer feeding grounds in cold, productive waters at high latitudes to warmer wintering grounds in tropical and subtropical areas, where they mate and calve. One of the fastest swimming whales, it can reach speeds of 25 knots. Tagged individuals have travelled 1700km in 9 days. A rare and Endangered species now, it was probably one of the most abundant large whales before commercial whaling. Typically swims in deeper waters along both coasts.
PLATE 101
LARGE WHALES WITH DORSAL FINS
BRYDE’S WHALE Balaenoptera edeni 11.9–14.8m; 12.2–15.6m, 11,300–16,200kg
Similar to Sei Whale, but smaller and only whale with three ridges on head and a prominent dorsal fin. Dark-backed with white on chin that grades into a light gray or purple-gray belly. Prominent dorsal fin is typically hooked, and intermediate in size and shape between those of Sei and Fin whales. Slender flippers, broad fluke. Skin may be mottled with scars. Baleen is black with a pale gray, coarse fringe. Feeds on a wide variety of fish, crustaceans, and krill. Blow is moderately high and thin, and dives last 1–11 minutes. Spectacular breaches often repeated two or three times. Breeding is in winter, with young born a year later, and weaned 6 months later in summer. Uses warm waters, typically south of Chesapeake Bay in the east and south of Baja in the west.
SEI WHALE Balae
noptera borealis 14–18.6m, 10,000–25,000kg
Large whale with one central ridge on head and a prominent dorsal fin. Dorsal fin is less hooked than that of Bryde’s Whale, and baleen is white and silky. Has thin, pointy flippers and a triangular fluke. Back is blueish gray, belly and chin are white. Skin may be mottled with scars. Females are slightly larger than males, and both sexes reach sexual maturity at 8–10 years, by which time they are 13m long. Mating occurs from September-March, and a single 4.5m, 65kg calf is born a year later. The lactation period is 6–9 months and females produce young every 2–3 years. Blow is low and forked. A rare and Endangered species. Rarely breaches, and feeds both by gulping and skimming krill, squid, and small fish. Seems to follow typical great whale pattern of migrating to higher latitudes for summer feeding and to tropical and subtropical waters for mating and calving in winter. Found on both coasts, far from shore.
COMMON MINKE WHALE balaenoptera acutorostrata 7.6–9.8m; 7.3–10.7m, 5000–9,000kg
Unique with white band on flippers and a sharply pointed snout. Flippers are rarely all dark. Hooked dorsal fin is largest, in relative size, of all baleen whales. Dark gray back. White on belly and chin extends dorsally in center of back. Baleen is yellowish white. Rarely has visible blow. Common, especially in cooler waters, where they are solitary or in small groups of 2 or 3, although larger aggregations may occur on exceptionally productive feeding grounds. They are attracted to boats, perhaps by the noise of the motor. Breeding occurs year-round, but more commonly from October–March, with young born 10 months later. Young are 2.5m long at birth and nurse for about 4–5 months. Animals grow steadily until they are about 30 years old. Often seen near coast while migrating north in spring and summer and farther offshore when returning south in autumn and winter.
PLATE 102
SMALL WHITE AND GRAY WHALES
SMALL SPERM WHALES - These are two of the smallest whales. Both have blunt, squarish heads and a conspicuous white crescent behind the eye forming a false gill. Their lower jaw is small and underslung. They are sharklike in appearance, with a dark bluish-gray back blending into a light gray or pink belly. The two species are distinguished by body size, position and size of the dorsal fin, and tooth number. Shy, sometimes leave a reddish-brown cloud of fecal “ink” if startled. They live in deep waters and are difficult to see as they typically surface and dive quietly.
DWARF SPERM WHALE Kogia sima 2.1–2.7m, 136–272kg
Has a prominent dorsal fin in center of back. Smaller than the Pygmy Sperm Whale, with fewer teeth (7–12 pairs). Feeds mainly on squid, but also takes fish and crustaceans, taken at depths of up to 300m. Seen off southeast coast along the continental shelf, rare strandings along west coast.
PYGMY SPERM WHALE Kogia breviceps 2.7–3.4m, 318–408kg
Small dorsal fin is positioned one third of the way to the tail. Larger than Dwarf Sperm Whale, with more teeth (12–16 pairs). Sometimes has pale circular mark in front of eye. Occurs along both coasts singly or in small groups of 2–6, most often seen off the southeastern coast.
RISSO’S DOLPHIN Grampus griseus 2.8–3.8m, 400–600kg
Unique with very large dorsal fin and rounded head. Blunt melon is creased down the middle when viewed head-on. Body is typically gray and scarred, but may be dark gray to white. Young are an unscarred brownish gray. Scars accumulate with age, and body color lightens. Typically in groups of 3–50 animals in offshore waters along both coasts.
NARWHAL Monodon monoceros (without tusk) 4.8m, 1580kg; 4.1m, 960kg
Only whale with a tusk; mottled gray color and rounded head also unique. Typically, only males have a tusk, which is a hollow, spiraling, modified tooth. Rarely two tusks are present. Older animals are almost white in coloration, and have a more convex trailing edge of their fluke. Tusks often break in fights over females, and scar the heads of males. Only found in high Arctic seas near pack ice.
BELUGA Delphinapterus leucas 3.5–4.9m, 800–1500kg; 3.3–4.0m, 540–790kg
White color and rounded head unmistakable. No dorsal fin, small broad flippers. Young are born slate gray to pinkish brown and mature into blueish-gray subadults. Skin turns white after sexual maturity, and may look yellow in some light. Males are larger, with a more pronounced melon. Chirps and whistles may be heard above the surface. Lives in groups of 5–20 along northern shorelines and estuaries.
PLATE 103
BLACK DOLPHINS
PILOT WHALES - These two bulbous-headed dolphins are jet black with a variable blaze of gray or white behind the eye, and light-colored patches on the belly and throat. They may also have a saddle of paler color behind the dorsal fin. The forward-sitting dorsal fin is bulbous and hooked in males, more upright in females. Their flukes have conspicuously pointed tips. Strong blow often visible. In addition to range, they are distinguished by the size of their flippers and their teeth-both of which are difficult to measure at sea.
LONG-FINNED PILOT WHALE Globicephala melas 6.2m, 2320kg; 5.12m, 1320kg
Has long flippers with a sharp elbow-like bend. 8–12 pairs of teeth. Swims in groups of 10–50 in northern and temperate waters off the east coast. Follow feeding squid inshore in summer and fall, then offshore in winter and spring. Also feed on mackerel.
SHORT-FINNED PILOT WHALE Globicephala macrorhynchus 5.5–7.0m; 4.25–5.0m, 900–3000kg
Short flippers have a gently curved edge. Seven to nine pairs of teeth. Nomadic groups of 10–30 in deep waters along the west, southeastern, and Caribbean coasts.
PYGMY KILLER WHALE Feresa attenuata 2.0–2.6m, 110–170kg
Small, black dolphin with rounded flipper tips and white “lips.” Snout is more rounded than Melon-headed Whale. May have a subtle dark brown cape on back that does not dip into flanks. 8–13 pairs of teeth. Typically avoids ships. Found off southeastern coast and Caribbean.
MELON-HEADED WHALE Peponocephala electra 2.1–2.7m, 160kg
Small, black dolphin with pointed flipper tips and white or pink “lips.” Snout is slightly more pointed than in the Pygmy Killer Whale. Back is dark, belly is lighter. May have a dark mask on face and a dark cape that dips toward belly on flanks. 20–25 pairs of teeth. Swims in groups of a few hundred far off the southeastern coast and Caribbean.
KILLER WHALE Orcinus orca 6.0–10.0m, 3500–7000kg
Large, black dolphin with high dorsal fin and white eyespot. Male is larger and has an erect dorsal fin, female has a smaller curved dorsal fin. Large paddle-shaped flippers grow with age. Belly, chin, and underfluke are white. Has variable white and gray swirls on sides. An acrobatic swimmer in all oceans including deep and shallow waters.
FALSE KILLER WHALE Pseudorca crassidens 3.7–6.0m; 3.3–5.1m, 1000–1360kg
Large, dark gray to black dolphin with sickle-shaped flippers. Short flippers have a hump at the center and slightly concave tip. Chest may be gray, and head paler. Dorsal fin may be pointed or round. Rare but widespread and approachable along both coasts, mostly in the south.
PLATE 104
UNSTRIPED, BEAKED DOLPHINS
ROUGH-TOOTHED DOLPHIN Steno bredanensis 2.0–2.6m; 2.0–2.5m, 90–155kg
Uniquely cone-shaped head lacks a groove separating forehead from beak. Lips and tip of beak are white. Eyes are large and slightly protruding. Dark gray or purplish back with darker cape and white belly. Some yellowish or white spots on flank. Deep divers with little interest in bow-riding. Maximum lifespan 32 years. Groups of 10–20 use deep warmer waters along both coasts.
BOTTLENOSE DOLPHIN Tursiops truncatus 2.6–3.4m, 150–300kg
Large, plain gray dolphin with short, wide beak, wide head and body, and long flippers. Tall dorsal fin mid-body and sickle-shaped. Flukes medium-sized with deep notch. Variable in size and color, some populations may have a few spots. Body is darkest on back, grading to white on belly. Feeds on fish and squid. Acrobatic and fond of bow-riding. Common in groups of 1–25, and up to several hundred along coastlines and far offshore.
ATLANTIC SPOTTED DOLPHIN Stenella
frontalis 1.7–2.3m, 100–143kg
Spotted dolphin with a gray band between eye and flipper. Dark dorsally with pale spots and white underside with dark spots. Dark and light color grade together on tail stock. Lips may be white. Calves born unspotted and about 1m long. Southern races are more heavily spotted than northern pelagic forms. Feed on fish, squid, and ocean floor invertebrates. Groups of 5–15 mainly in warm Atlantic waters within 300km of the coast.
PANTROPICAL SPOTTED DOLPHIN Stenella attenuata 1.6–2.6m; 1.7–2.4m, 90–119kg
Spotted dolphin with prominent dark dorsal cape. Has dark gray band between jaw and flipper and a clear division of dark and light color on tail stock. Lips are white. Calves get first spots on belly. Dorsal fin shape is variable. Groups may reach thousands. Females bear a single young after gestation period of almost a year. Frequently associates with large schools of tuna, making them susceptible to purse seines. Found in tropical waters and most of the Atlantic coast, where it is typically offshore.