HUMPBACK WHALE

The humpback whale is one of the rorquals, a family that includes the blue whale, fin whale, Bryde's whale, sei whale, and minke whale. Rorquals have two characteristics in common: dorsal fins on their backs, and ventral pleats running from the tip of the lower jaw back to the belly area. The shape and color pattern on the humpback whale's dorsal fin and fluke (tail) are as individual in each animal as are fingerprints in humans. The discovery of this interesting fact changed the course of cetacean research forever, and the new form of research known as "photo-identification," in which individuals are identified, catalogued, and monitored, has led to valuable information about such things as humpback whale population sizes, migration, sexual maturity, and behavior patterns.

PHYSICAL DESCRIPTION

The head of a humpback whale is broad and rounded when viewed from above, but slim in profile. The body is not as streamlined as other rorquals, but is quite round, narrowing to a slender peduncle (tail stock). The top of the head and lower jaw have rounded, bump-like knobs, each containing at least one stiff hair. The purpose of these hairs is not known, though they may provide the whale with a sense of "touch." There are between 20-35 ventral grooves which extend slightly beyond the navel.

COLOR

The body is black on the dorsal (upper) side, and mottled black and white on the ventral (under) side. This color pattern extends to the fluke. When the humpback whale "sounds" (goes into a long or deep dive) it usually throws its fluke upward, exposing the black and white patterned underside. This pattern is distinctive to each whale. The flippers range from all white to all black.

FINS AND FLUKE

About 2/3 back on the body is an irregularly shaped dorsal (top) fin. Its flippers are very long, between 1/4 and 1/3 the length of its body, and have large knobs on the leading edge. The fluke (tail), which can be 18 feet (5.5 m) wide, is serrated and pointed at the tips.

LENGTH AND WEIGHT

Adult males measure 40-48 feet (12.2-14.6 m), adult females measure 45-50 feet (13.7-15.2 m). They weigh 25 to 40 tons (22,680-36,287 kg).

FEEDING

Humpback whales feed on krill, small shrimp-like crustaceans, and various kinds of small fish. Each whale eats up to 1 and 1/2 tons (1,361 kg) of food a day. As a baleen whale, it has a series of 270-400 fringed overlapping plates hanging from each side of the upper jaw, where teeth might otherwise be located. These plates consist of a fingernail-like material called keratin that frays out into fine hairs on the ends inside the mouth near the tongue. The plates are black and measure about 30 inches (76 cm) in length. During feeding, large volumes of water and food can be taken into the mouth because the pleated grooves in the throat expand. As the mouth closes water is expelled through the baleen plates, which trap the food on the inside near the tongue to be swallowed.

MATING AND BREEDING

Humpback whales reach sexual maturity at 6-8 years of age or when males reach the length of 36 feet (11.6 m) and females are 40 feet (12 m). Each female typically bears a calf every 2-3 years and the gestation period is 12 months. A humpback whale calf is between 10-15 feet (3-4.5 m) long at birth, and weighs up to 1 ton (907 kg). It nurses frequently on the mother's rich milk, which has a 45% to 60% fat content. The calf is weaned to solid food when it is about a year old.

DISTRIBUTION AND MIGRATION

Found in all the world's oceans, most populations of humpback whales follow a regular migration route, summering in temperate and polar waters for feeding, and wintering in tropical waters for mating and calving.

NATURAL HISTORY

At least 3 different species of barnacles are commonly found on both the flippers and the body of the humpback whale. It is also home for a species of whale lice, Cyamus boopis .

Humpback whales are active, acrobatic whales. They can throw themselves completely out of the water (breaching), and swim on their backs with both flippers in the air. They also engage in "tail lobbing" (raising their huge fluke out of the water and then slapping it on the surface) and "flipper slapping" (using their flippers to slap the water). It is possible that these behaviors are important in communication between humpbacks.

Perhaps the most interesting behavior of humpback whales is their "singing." Scientists have discovered that humpback whales sing long, complex "songs." Whales in the North American Atlantic population sing the same song, and all the whales in the North American Pacific population sing the same song but the songs of each of these populations and of those in other areas of the world are uniquely different. A typical song lasts from 10-20 minutes, is repeated continuously for hours at a time, and changes gradually from year to year. It appears that all the singing whales are males and that the songs may be a part of mating behavior.

STATUS

Because their feeding, mating, and calving grounds are close to shore and because they are slow swimmers, the humpback whales were an easy target for early whalers. Between 1905 and 1965, 28,000 humpback whales were killed. The International Whaling Commission (IWC) gave them worldwide protection status in 1966. It is believed they number about 15,000-20,000 at present, or about 15-20% of the original population.

FIN WHALE

The fin whale is one of the rorquals, a family that includes the humpback whale, blue whale, Bryde's whale, sei whale, and minke whale. The fin, or finback whale is second only to the blue whale in size and weight. Among the fastest of the great whales, it is capable of bursts of speed of up to 23 mph (37 km/hr) leading to its description as the "greyhound of the sea." Its most unusual characteristic is the asymmetrical coloring of the lower jaw, which is white or creamy yellow on the right side and mottled black on the left side. Fin whales are found in all oceans of the world, though they seem to prefer temperate, arctic, and antarctic waters to tropical seas.

PHYSICAL DESCRIPTION

The fin whale is long, sleek, and streamlined, with a V-shaped head which is flat on top. A single ridge extends from the blowhole to the tip of the rostrum (upper jaw). There is a series of 56-100 pleats or grooves on the underside of its body extending from under the lower jaw to the navel.

COLOR

The fin whale is light gray to brownish-black on its back and sides. Two lighter "colored" chevrons begin midline behind the blowholes and slant down the sides towards the fluke (tail) on a diagonal upward to the dorsal fin, sometimes recurving forward on the back. It is never posterior to the dorsal fin. The underside of its body, flippers, and fluke are white. The lower jaw is gray or black on the left side and creamy white on the right side. This asymmetrical coloration extends to the baleen plates as well, and is reversed on the tongue.

FINS AND FLUKE

The fin whale has a prominent, falcate (curved) dorsal fin located far back on its body. Its flippers are small and tapered, and its fluke is wide, pointed at the tip, and notched in the center.

LENGTH AND WEIGHT

Adult males measure up to 78 feet (24 m) in the northern hemisphere, and 88 feet (26.8 m) in the southern hemisphere. Females are slightly larger than males. Weight for both sexes is between 50-70 tons (45,360-63,500 kg).

FEEDING

Fin whales feed mainly on small shrimp-like creatures called krill or euphausiids and schooling fish. They have been observed circling schools of fish at high speed, rolling the fish into compact balls then turning on their right side to engulf the fish. Their color pattern, including their asymmetrical jaw color, may somehow aid in the capture of such prey. They can consume up to 2 tons (1,814 kg) of food a day. As a baleen whale, it has a series of 262-473 fringed overlapping plates hanging from each side of the upper jaw, where teeth might otherwise be located. These plates consist of a fingernail-like material called keratin that frays out into fine hairs on the ends inside the mouth near the tongue. The baleen on the left side of the mouth has alternating bands of creamy-yellow and blue-gray color. On the right side, the forward 1/3 section of the plates is all creamy-yellow. The plates can measure up to 30 inches (76 cm) in length and 12 inches (30 cm) in width. During feeding, large volumes of water and food can be taken into the mouth because the pleated grooves in the throat expand. As the mouth closes water is expelled through the baleen plates, which trap the food on the inside near the tongue to be swallowed.

MATING AND BREEDING

Adult males reach sexual maturity at about 6-10 years of age. As in some other whales, sexual maturity is reached before physical maturity. Gestation is 12 months, and calves are born at 3 year intervals. Length at birth is 14-20 feet ( 5.5 -6.5 m) and weight is 2 tons (1,814 kg). Calves nurse for 6 months and are weaned when they are 30-40 feet (10-12 m) in length.

DISTRIBUTION AND MIGRATION

Fin whales are found in all oceans of the world. They may migrate to subtropical waters for mating and calving during the winter months and to the colder areas of the Arctic and Antarctic for feeding during the summer months; although recent evidence suggests that during winter fin whales may be dispersed in deep ocean waters as opposed to migrating between wintering and summering regions.

NATURAL HISTORY

Fin whales are found most often alone, but groups of 3-7 individuals are common, and association of larger numbers or concentrations may occur in some areas at times. The fin whale's blow is tall and shaped like an inverted cone, and the dive sequence is 5-8 blows approximately 70 seconds apart before a long dive. It does not raise its fluke as it begins the long dive, which can be as deep as 755 feet (230 m)

STATUS

Their speed, plus the fact that they prefer the vastness of the open sea, gave them almost complete protection from the early whalers. With modern whaling methods, however, finback whales became easy victims. As blue whales became depleted, the whaling industry turned to the smaller, still abundant fin whales as a replacement. As many as 30,000 fin whales were slaughtered each year from 1935 to 1965. The International Whaling Commission (IWC) placed them under full protection in 1966 beginning with the North Pacific population. The present populations are estimated to be about 40,000 in the northern hemisphere and there may be as many as 15,000-20,000 in the southern hemisphere, a small percentage of the original population levels.

MINKE WHALE

GENERAL DESCRIPTION

The minke whale is the smallest baleen whale with 50-70 throat grooves. It is a rorqual whale (baleen whale with throat grooves). They are the most abundant baleen whale. Minke whales have a characteristic white band on each flipper, contrasting with its very dark gray top color. They have 2 blowholes, like all baleen whales.

SIZE

Minke whales grow to be about 25-30 feet (7.8-9 m) long, weighing about 6-7.5 tons (5.4-6.8 tonnes).. Females are about 2 feet (0.6 m) longer than males, as with all baleen whales. The largest minke whale was about 35 feet (10.5 m) long weighing 9.5 tons (8.6 tonnes).. Minke whales have a snout that is distinctively triangular, narrow, and pointed (hence its nicknames "sharp-headed finner" and "little piked whale").

SKIN, SHAPE AND FINS

The minke whale's skin is very dark gray above and lighter below, sometimes with pale trapezoidal stripes behind the flippers on the top. Minke whales have a characteristic white band on each flipper (this is absent on the southern minke whales).

Minke whales are stocky, having a layer of blubber several inches thick. They have 50-70 throat grooves, running from the chin to the mid-section. The minke whale has two long flippers (up to 1/8 of the body size), a small dorsal fin, and a series of small ridges along the its back near the flukes (tail).

DIET AND BALEEN

Minke whales (like all baleen whales) are seasonal feeders and carnivores. They sieve through the ocean water with their baleen. They filters out small polar plankton , krill , and small fish, even chasing schools of sardines, anchovies, cod, herring, and capelin. They have the same diet as blue whales.

The baleen plates in the minke whale's jaws have about 300 pairs of short, smooth baleen plates. The largest plates are about less than 12 inches (30 cm) long and 5 inches (13 cm) wide. The fine textured baleen bristles are fringed and are creamy-white with pure white bristles..

SOCIAL GROUPS

Minke whales either travel singly or congregated in small pods of about 2-3 whales.

DIVING

Minke whales can dive for up to 20-25 minutes, but usually make shorter dives, lasting about 10-12 minutes. Just before diving, minke whales arch their back to a great degree, but the flukes do not rise out of the water.

SPOUTING-BREATHING

Minke whales breathe air at the surface of the water through 2 blowholes located near the top of the head. At rest, minke whales spout (breathe) about 5-6 times per minute. The spout of the minke whale is a very low, almost inconspicuous stream that rises up to 6.5 feet (2 m) above the water. Minke whales start to exhaling before they reach the surface; this minimizes the blow.

SPEED

Minke whales normally swim 3-16 mph (4.8-25 kph), but can go up to 18-21 mph (29-34 kph) in bursts when in danger. Feeding speeds are slower, about 1-6 mph (1.6-9.8 kph).

VOCALIZATION

Minke whales makes very loud sounds, up to 152 decibels (as loud as a jet taking off). They make series (trains) of grunts, thuds, and raspy sounds, usually in the 100-200 Hertz range. These sounds may be used in communication with other minke whales and in echolocation.

HABITAT AND RANGE

Minke whales live at the surface of the ocean in all but polar seas.

REPRODUCTION

Minke whale breeding occurs mostly in the late winter to early spring while near the surface and in warm waters. The gestation period is about 10 months and the calf is born near the surface of the warm, shallow waters. The newborn instinctively swims to the surface within 10 seconds for its first breath; it is helped by its mother, using her flippers. Within 30 minutes of its birth the baby whale can swim. The newborn calf is about 9 feet (2.8 m) long and weighs about 1,000 pounds (454 kg). The baby is nurtured with its mother's milk. The mother and calf may stay together for a year or longer. Minke whales reach puberty at 2 years of age.

LIFE SPAN

Minke whales have a life expectancy of over 20 years.

POPULATION COUNT

Minke whales are the most abundant baleen whale. It is estimated that there are about almost 800,000 minke whales world-wide.

CLASSIFICATION

Minke whales (Balaenoptera acutorostrata) are baleen whales (Suborder Mysticeti). They are one of 76 cetacean species, and are marine mammals.

PILOT WHALE

(Globicephala melas) long-finned

(Globicephala macrorhynchus) short-finned

The pilot whale, like the killer whale, is a member of the dolphin family, and is second only to the killer whale in size. It does well in captivity, and is easily trained, displaying intelligence equal to that of the bottlenose dolphin. One captive pilot whale named Morgan was trained by Navy scientists to retrieve beeper-attached objects from the ocean floor at depths of over 1,600 feet. Carrying a clamping recovery device in his mouth, he attached it to the located object, which was then raised to the surface by compressed air balloons. The pilot whale is extremely social, and is well known for stranding in groups of a few animals to several hundred at a time.

PHYSICAL DESCRIPTION     The pilot whale has a distinct rounded head with a very slight beak and an up-curved mouthline. In males the rounded head may protrude up to 4 inches over the lower jaw. Its body is long and stocky, narrowing along the caudal peduncle (tailstock).

COLOR     Generally all black to coal gray, the pilot whale has a white or light gray anchor-shaped patch on its ventral (bottom) surface. The short-finned pilot whale has a faint gray saddle patch behind the dorsal (top) fin.

FINS AND FLUKES     Its dorsal fin is placed slightly forward of the center of the body and is triangular in shape, and the flippers are very small and rounded at the tips. Flukes are small and pointed at the tips with a slight center notch.

LENGTH AND WEIGHT     Adult males measure, on average, 20 feet (6.1 m) and weigh about 3 tons. Adult females generally measure 16 feet (4.9 m) and weigh about 2 tons. Male pilot whales are larger than females.

FEEDING     The pilot whale feeds primarily on squid, although it's known to eat octopus, cuttlefish, herring and other small fish when squid is unavailable. It has only 40 to 48 teeth, compared to 120 in many other dolphin species. This may represent an evolutionary trend toward fewer teeth in squid eaters. Its teeth are used only for catching/grasping. An adult pilot whale may eat up to 30 pounds per day.

In Newfoundland , pilot whales have been seen hunting in groups to help concentrate their prey. One pod was observed entering a bay in a line, slowly closing the line into a circle, and trapping the prey in the center. Powerful high-pitched whistles appear to be involved in coordinating this activity.

MATING AND BREEDING     Males reach sexual maturity at about 15 to 16 feet (4.6 m) and 12 years of age. Females reach sexual maturity at about 12 feet (3.7 m) and 6 to 7 years of age. Gestation lasts approx. 15 to 16 months and calving occurs once every 3 to 5 years. Calves are generally 6 feet (1.8 m) at birth, and weigh about 225 pounds. The calf nurses for up to 22 months, with some evidence for longer lactation and extensive mother calf bonds. Most calves are born in late summer, though some calving occurs throughout the year. The males may compete for mates with fights involving butting, biting, and ramming. Mating also involves these activities, and some females carry scars from bites inflicted by males during the breeding season.

DISTRIBUTION AND MIGRATION     In general, pilot whales are found in both the northern and southern hemispheres, in tropical and temperate waters throughout the world. Short-finned pilot whales tend to be found in warmer waters, while cold and more temperate waters are preferred by the long-finned variety. There are some areas of overlap between the two species, but they remain segregated in most areas.

BEHAVIOR AND NATURAL HISTORY     Pilot whales are very social, and are often found in groups of 15 to 200. Within these groups are at least some stable associations. Overall, three kinds of groups have been distinguished: traveling/hunting groups, feeding groups, and resting groups. When traveling or hunting, the group is quite cohesive. The group has a looser, less cohesive structure when feeding or resting. During the latter activity, groups of 12 to 30 are found resting, nursing and at times, mating. Males often patrol the perimeter of such groups. Partly because of their social nature, pilot whales are often involved in mass strandings. In this century, mass strandings of as many as several hundred pilot whales at one time have been recorded. Although no one knows why these beachings occur, some may result from persistence to keep the group together. Other reasons may involve mis-navigation when following prey, when traveling (possibly due to irregularities in the magnetic field), or possible parasitic infections resulting in neurological disorders.

POPULATION STATUS     Figures for both species of pilot whales are unknown, and even though they are depleted in some areas, pilot whales are not considered to be endangered. Humans have taken advantage of the social nature of pilot whales. "Drive fisheries," where groups are herded to the beach for slaughter, have taken place on Cape Cod ; Newfoundland ; the Faroe, Shetland, and Orkney Islands ; Iceland ; and Norway . The whales have been killed for meat, bone, fertilizer, and oil. In some places, such as the Faroe Islands , the kill continues today despite an obvious decrease in whale numbers. One drive fishery in Newfoundland killed over 50,000 whales between 1951 and 1961, rapidly decreasing the number of pilot whales in Newfoundland waters. Other kills have not had such a drastic effect. Pilot whales are also being used by man as exhibition animals. They are displayed in many aquaria and zoos. Recently the Navy was able to train pilot whales in programs to help them retrieive lost objects. The large brain and intelligence of this species lends them to such tasks, and we may see more trained pilot whales used in the future.

SEI WHALE

Size: Length: Males 17.1 m, females 18.6 m. Slightly larger in the Southern Hemisphere.

Habitat: Temperate marine waters. Prefers deep oceanic waters. Spend winters in temperate waters and move to higher latitudes in the summer.

Range: Atlantic and Pacific Oceans in both hemispheres.

Diet: Plankton, including krill, copepods, and amphipods.

Reproduction: Females are sexually mature at about 5-6 years old. Mating takes place in the late fall and early winter. Exact gestation period is not known, but it is somewhere around 10.5-12.5 months, and the calf nurses for 5-9 months. Calves are 4.5-4.8 m long at birth.

Comments: Generally travel in small groups of 2-5 individuals.

Conservation Notes: Listed as an endangered species under the ESA. Commercial whaling of this species was halted by the IWC in 1980 everywhere but the North Atlantic . The Sei Whale is listed in CITES Appendices I and II.

NORTHERN RIGHT WHALE

Common Name: Northern Right Whale

Size: Female maximum length 16.5 - 18 m (depending on measurement method used). Females are larger than males.

Habitat: Warm and cold marine waters.

Range: From 30° to 62° North latitude in the North Atlantic Ocean. Northern Atlantic, North Pacific, and Southern populations do not appear to mix.

Diet: Feed almost exclusively on calanoid copepods, concentrating on aggregations of these copepods.

Reproduction: Calving takes place from December to April in the North Atlantic. Calves are approximately 6 m at birth. Females are extremely attached to their calves.

Comments: Right whales are either solitary or travelling in small groups. They do gather in large numbers in areas of good feeding.

Conservation Notes: This species is extremely endangered. The ESA and IUCN both list the Northern Right Whale as an endangered species . Most commercial exploitation of this species was halted by the 1920's, and it is now protected in more than 120 countries. Entanglement and ship-strikes are still major concerns. Unfortunately, the population is showing little signs of recovering.

SPERM WHALE

Physeter macrocephalus

Size: Length: Females 11-12 m. Males 15-18 m.

Habitat: Deep marine waters, warm and cold.

Range: Equatorial to polar in all world's oceans.

Diet: Large squid, octopuses, demersal fish, rays, sharks, sometimes crustaceans.

Reproduction: Mating season takes place from late winter to early summer. Gestation period is approximately 14-15 months, young are 3.5-4.5 m long at birth. Calves nurse for up to 2 years.

Comments: Females and young and immature males gather in breeding schools, while groups of sexually mature males are called bachelor schools. The largest males, those that visit the breeding schools to mate, are typically solitary or travel in very small groups.

Conservation Notes: The Sperm Whale is listed as an endangered species under the ESA. IWC regulations have halted the commercial take of this species. Listed in CITES Appendices I and (for some countries) II. There is some concern over the number of Sperm Whales entangled in fishing gear.