Megaptera novaeangliae

The Humpback whale (Megaptera novaeangliae), is a very large marine mammal, in the family of Rorquals (Balaenoptera), part of the order of cetaceans. The Humpback is a baleen whale, so that instead of teeth, it has long plates which hang in a row (like the teeth of a comb) from its upper jaws. Baleen plates are strong and flexible; they are made of a protein similar to human fingernails. Baleen plates are broad at the base (gumline) and taper into a fringe which forms a curtain or mat inside the whale's mouth. All baleen whales strain huge volumes of ocean water through their baleen plates to capture food: tons of krill, other zooplankton, crustaceans and small fish.

The humpback whale is renowned for its impressive leaping displays and for the mysterious singing of solitary males. Humpback whales are among the best-studied cetaceans, and yet they are among the most mysterious. Their songs and the complex social behaviors that accompany them comprise some of the greatest incompletely understood phenomena. These songs are intricate, with up to nine musical themes. Males may sing for days, changing themes over time, but all the males from one population will sing a similar song. Humpbacks are popular subjects for whale-watching ecotourism. They are readily identified by enormous, wing-like flippers, which are far longer than in any other whale species. They are known for spectacular displays at the surface. They breach, leaping headfirst out of the water; slap the surface with a long flipper; or slam the tail flukes repeatedly. Humpbacks may be the only whales to trap or herd prey into a bunch to make feeding more efficient. They concentrate a school of fish into a stack by blowing columns of bubbles to form a circle around it, and then lunge into the mass to feed.

The robust body is blue-black in colour, with pale or white undersides. The flippers may also be white and are the largest appendage of any animal; reaching up to five metres in length. On the underside of the mouth are 12 to 36 throat grooves, which can expand when filtering water during feeding. Humpbacks have characteristically knobbly heads, covered in many raised lumps (or tubercles) and barnacles. There are two blowholes on the back and the spout of water can appear very bushy. The spreading tail flukes have a distinct indentation in the middle; as the whale undertakes a deep dive it usually arches its back (hence the common name) so that the tail flukes are raised above the water and clearly visible. The pattern on the underside of the flukes is unique to an individual and thus can be used to photo-identify and track individuals.

The magnificent humpback whale is renowned for its impressive leaping displays and for the mysterious 'singing' of solitary males. The robust body is blue-black in colour, with pale or white undersides (6). The flippers may also be white and are the largest appendage of any animal; reaching up to five metres in length (2). On the underside of the mouth are 12 to 36 throat grooves, which can expand when filtering water during feeding (3). Humpbacks have characteristically knobbly heads, covered in many raised lumps ('tubercles') and barnacles (6) (7). There are two blowholes on the back and the spout of water can appear very bushy (6). The spreading tail flukes have a distinct indentation in the middle (8); as the whale undertakes a deep dive it usually arches its back (hence the common name) so that the tail flukes are raised above the water and clearly visible (7). The pattern on the underside of the flukes is unique and can be used to photo-identify and track individuals (3).

Humpbacks are baleen whales; they have large, sieve like plates of baleen (a similar material to human hair or nails) hanging down from the inside of their mouths which function to filter planktonic organisms from the water (2). Individuals can open their mouths widely, due to the throat grooves, and thus engulf large quantities of water (8). Humpbacks often lunge into a shoal of prey but have also been observed herding their prey into clusters or using a 'bubble net' to effectively trap greater numbers. During this process, a number of whales will circle underwater emitting a continuous stream of air which traps fish in the centre of the ring, the whales then surface up through their 'net' gorging on the contents within (2). During the summer months, humpbacks must feed intensely as they do not feed again during either the migration or the time spent in tropical breeding grounds (8). Males compete for females directly by escorting receptive mates and aggressively defending them, their famous 'song' is also thought to be a form of courtship (8). Solitary males sing highly complex songs that are similar within a population but evolve over successive seasons (8). Calves are born after a 10 to 12 month gestation period, they accompany their mother on the return migration to polar feeding grounds, and studies have shown that individuals return to the same feeding ground consistently year after year (8). Possibly one of the best-known aspects of humpback whale behaviour is their acrobatic aerial display; the most spectacular of which is breaching, when the body of the whale may completely leave the water, returning with an enormous splash (7).

Humpback whales, Megaptera novaeangliae, live in polar and tropical waters, particularly those of the Atlantic, Arctic, and Pacific Oceans. Their range also includes the waters of the Bering Sea and the waters surrounding Antarctica.

Biogeographic Regions: arctic ocean (Native ); atlantic ocean (Native ); pacific ocean (Native )

Antarctica/Southern Ocean; East Pacific; Eastern Atlantic Ocean; Indo-West Pacific; Western Atlantic Ocean

in all oceans

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) Range encompasses the world's oceans from the subtropics to high latitudes. All subpopulations (except the one in the Arabian Sea) migrate between mating and calving grounds in tropical/subtropical waters, usually near continental coastlines or island groups, and productive colder waters in temperate and high latitudes (Reilly et al. 2008).

Historic Range:
Oceanic

Arctic to Antarctic waters in all oceans.

Arctic to Antarctic waters in all oceans.

Humpback whales are found throughout the world's oceans. They undertake yearly migrations of thousands of kilometres from summer feeding grounds in polar waters to winter breeding grounds near to the tropics (7). Indeed, individuals feeding south of Cape Horn undertake the longest known migration of any mammal, in order to breed in the warm waters off Columbia and Costa Rica (3).

The cerebellum of humpback whales constitutes about 20% of the total weight of the brain; the brain does not differ much from those of other mysticete whales.

The olfactory organs of humpback whales are greatly reduced and it is doubtful whether they have a sense of smell at all. Their eyes are small and adapted to withstand water pressure. Their external auditory passages are narrow, leading to a minute hole on the head not far behind the eye.

Humpback females are larger than males. They are one of the few species of mammals for which this is true.

The most distictive external features of humpbacks are the flipper size and form, fluke coloration and shape, and dorsal fin shape. Flippers are quite long and can be almost a third of the body length. They are largely white and have knobs on the leading edge. The butterfly-shaped tail flukes bear individually distinctive patterns of gray and white, and have a scalloped trailing edge. The dorsal fin can be a small triangle or sharply falcate, and often has a stepped or humped shape; this is one source of the name "humpback."

There are 14 to 35 ventral pleats or grooves.

Humpbacks have the greatest relative blubber thickness for their size of any rorqual. Megaptera novaeangliae is second only to blue whales in absolute thickness of blubber. Blubber thickness varies at different times of the year, as well as with age and physiological condition.

Baleen plates are usually all black with blackish bristles.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: female larger

Average mass: 3e+07 g.

Length: 1300 cm

Weight: 3.0E7 grams

Distinguishing characteristics: colour in the northern hemisphere is dark with white belly and on flippers, but southern hemisphere whales have more white. Sensory knobs on head. Lifts tail when diving. Variably curved dorsal fin midback on a hump. "Knuckles" or bumps along tail stock of thin whales. Flippers may reach length of 4.5 m (15'). Individuals recognized by underside of flukes and body scars/markings.

Differs from all other large whales in the very large and often white or partially white flippers, the knobs on the head, and the irregular rather than smooth rear margin of the tail fluke (Leatherwood and Reeves 1983). Dorsal fin varies such that it may resemble those of the blue whale, fin whale, or sei whale.

The habitat of humpback whales consists of polar to tropical waters, including the waters of the Artic, Atlantic, and Pacific Oceans, as well as the waters surrounding Antartica and the Bering Strait. During migration, they are found in coastal and deep oceanic waters. Generally, they do not come into coastal waters until they reach the lattitudes of Long Island, New York, and Cape Cod, Massachessetts.

Humpbacks are divided into several populations. These are for the most part isolated, but with a little interchange in some cases. There are two stocks in the north Atlantic Ocean and two in the north Pacific. There are also seven isolated stocks in the southern hemisphere.

Habitat Regions: temperate ; tropical ; polar ; saltwater or marine

Aquatic Biomes: benthic ; coastal

Inshore on feeding and calving grounds, but high seas in transit between them.

Depth range based on 15141 specimens in 1 taxon.
Water temperature and chemistry ranges based on 7774 samples.

Environmental ranges
  Depth range (m): 0 - 0
  Temperature range (°C): -1.581 - 29.319
  Nitrate (umol/L): 0.038 - 29.526
  Salinity (PPS): 30.132 - 37.870
  Oxygen (ml/l): 4.401 - 8.759
  Phosphate (umol/l): 0.034 - 1.983
  Silicate (umol/l): 0.494 - 87.357

Graphical representation

Temperature range (°C): -1.581 - 29.319

Nitrate (umol/L): 0.038 - 29.526

Salinity (PPS): 30.132 - 37.870

Oxygen (ml/l): 4.401 - 8.759

Phosphate (umol/l): 0.034 - 1.983

Silicate (umol/l): 0.494 - 87.357
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Habitat Type: Marine

Comments: Habitat includes the open ocean and coastal waters, sometimes including inshore areas such as bays. Summer distribution is in temperate and subpolar waters. In winter, most humpbacks are in tropical/subtropical waters near islands or coasts.

In the western North Atlantic, humpbacks give birth mainly over shallow wide banks near islands. In Hawaii, they concentrate over shallower waters near islands (Tomich 1986); groups including a calf tend to occur in shallower waters than do groups lacking a calf (Smultea 1994).

Warm and cold marine waters. Spends winter in tropical waters.

Warm and cold marine waters. Spends winter in tropical waters.

These whales are found in both tropical and polar areas depending on the season and are associated with shallow, coastal waters (7).

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

In the western North Atlantic, most humpbacks depart breeding areas in late winter-early spring. They arrive in northern feeding areas in 1-2 months; in the southern Gulf of Maine, they commonly return to the same area in successive years (Clapham et al., 1993, Can. J. Zool. 71:440-443). Southward migration occurs in fall; individuals arrive in breeding areas in 1-2 months. This species occurs off Hawaii mainly January-March.

Resightings of photoidentified individuals indicate that individuals may winter in widely separated areas in different years; at least some individuals may occupy widely separated areas in a single spring-summer season (e.g., Hawaii and Mexico, Hawaii and Japan, Japan and British Columbia) (see Darling and Mori 1993; Marine Mammal Sci. 12:281-287, [1996]; Salden et al. 1999). The fastest documented migration from southeastern Alaska to Hawaii took 39 days (Marine Mammal Sci. 12:457-464).

Like minke whales, and fin whales, humpbacks are generalized feeders. They are highly mobile and opportunistic. Humpbacks feed upon plankton, the plant and animal life at the surface of the ocean's water, or upon fish in large patches or schools. Because of this, humpbacks are classified as "swallowers" and not "skimmers." They do eat commercially exploited fishes. Feeding by humpbacks takes place during the summer.

Atka makerel and Pacific saury are the most commonly found fish prey of humpbacks in the eastern North Pacific Ocean. The former is considered one of the favorite foods of humpback whales in waters off the Western Aleutians and South of the Amchitka Islands. In addition, humpbacks in the North Pacific and the Bering Sea eat euphausiids (krill), mackerel, sand lance, Ammodytes americanus, capelin and herring.

Fishes comprise about 95% of the diet of North Atlantic humpbacks. Those humpbacks living in the Atlantic Ocean, specifically near Cape Cod and Greenland, also eat sand lance, herring and pollock.

Humpbacks near Australia and in the Antartic also feed on euphausiids.

Typically, these whales take both food and water into their mouths. Large volumes can be accomodated because the ventral grooves in the throat allow for expansion. Once the mouth is full, it is closed and the water is pressed out. Meanwhile, the food is caught in the baleen plates and is then swallowed. This process is aided by the internal mechanism of rorqual feeding--the tongue.

Humpbacks have five main feeding behaviors (the first three are more commonly observed than the last two):

1. Ring of foam. Humpbacks have an elaborate feeding behavior in which they lie on the ocean's surface and swim in a circle. While doing so, they strike the water with their flukes forming a "ring of foam," which surrounds their prey. Then, they dive under the ring and resurface in the center with mouth open, allowing them to capture the prey within the ring.
2. Lunging. Humpbacks feed by swimming vertically or obliquely up through aggregations of plankton or fish. This occurs only when their food is abundant. In addition, some variation may occur by means of lateral and/or inverted lunging.
3. Bubble behavior. When these whales use underwater exhalation to create bubble clouds and bubble columns.

Bubble clouds are large inter-connected masses of bubbles formed by one underwater exhalation. Clouds concentrate or herd a mass of prey. Feeding is presumed to occur underwater. After that the humpback rises slowly to the surface within the bubble cloud. After several blows and some shallow diving, the manuever is repeated. Bubble clouds appear to assist in prey detection or capture by immobilizing or confusing prey. Bubble clouds may cause a jumping response among the prey, helping the whale to detect the prey, or it may disguise the whale from the prey.

Bubble columns are formed as a humpback swims underwater in a broad circle while exhaling. An individual column may form rows, semicircles, or complete circles. These circles act like a seive net, concentrating or herding the prey.

4. Tail slashing. In this method of feeding, the individual whale swims in a large circle while slashing its tail through the water. The actual feeding takes place in the center of the turbulence.
5. Inside loop behavior. A whale can make a shallow dive, while hitting the water with its fluke as it submerges. A 180 degree roll is then rapily executed as the animal makes a sharp U turn (the "inside loop") and then lunge feeds slowly through the turbulent area created by its flukes. The whale feeds beside the area of turbulence.
6. Flick-feeding. this occurs only when whales eat euphausiids.

At times, humpbacks combine some of these methods, for example, combining bubble feeding and tail slapping (lobtailing), as they feed on sand lance.

It is important to note that no humpback younger than two years old uses the tail slapping method, although they are weaned from their mothers at one year. However, rudimentary lobtail feeding has been witnessed several times among older post-weaning young.

In addition, no difference has been noted in the frequency of lobtail feeding between the sexes.

Animal Foods: fish; zooplankton

Foraging Behavior: filter-feeding

Primary Diet: carnivore (Piscivore ); planktivore

Comments: This species is primarily dependent upon schooling fishes and krill (essentially krill only in the Southern Hemisphere). Feeding occurs singly or in groups, at the surface or while submerged, mainly in high latitudes, though stranded individuals in Virginia and Georgia had eaten sciaenid fishes (Laerm et al. 19970.

Humpback whales employ a wide variety of foraging methods, including cooperative feeding on prey enclosed in "nets" of exhaled air bubbles.

10,000 - 100,000 individuals

Comments: Population size based on counts in breeding areas is greater than 66,600. North Pacific: ~18,300 (2004-2006; Calambokidis et al. 2008); North Atlantic: 10,290-13,990 (early 1990s; Stevick et al. 2003); Southern Hemisphere: at least 36,763 (Reilly et al. 2008).

Humpback whales travel singly, in pairs or trios, or in groups of usually about 10-15. They may form stable feeding groups that stay together throughout the summer and that reform in subsequent summers.

This species sometimes has succumbed to local die-offs off the northeastern United States, due apparently to ingestion of prey containing red tide toxins (IUCN 1991).

Comments: Active day/night.

Average lifespan
Status: wild: 77.0 years.

Average lifespan
Status: wild: 95.0 years.

Humpbacks appear to possess a polygynous/polygamous mating system, with males competing aggressively for access to oestrous females.

Mating System: polygynous

The reproductive habits of humpback whales are typically mammalian. The breeding season is during the winter, and breeding takes place in tropical waters.

There are few actual observations of copulation in this species. The male and the female first swim in a line; they then engage in rolling, flipping, and tail fluking. Next, both dive and then surface vertically, with ventral surfaces "in close contact." They emerge from the water to a point below their flippers. They then fall back onto the surface of the water together. The gestation period lasts 11 to 11.5 months. During that time the embryo grows approximately 17 to 35 cm per month.

Sexual maturity is usually reached between 4 to 5 years. In males, the length of the penis can be an indication of sexual maturity. However, in some cases, puberty may proceed sexual maturity by one year. In sexually mature males, the weight of the testes and the rate of spermatogenesis increase during the breeding season, coinciding with the ovulation of the females. In the females, after sexual maturity is reached, ovary weight remains fairly constant. As ovulation approaches, "resting" Graafian follicles on the surface of the ovaries enlarge. There generally is only one ovulation per breeding season.

Breeding usually takes place once every two years, but it may occur twice every three years. In the latter situation, lactation may last longer that 5 months.

If a female is impregnated shortly after parturition, pregnancy and lactation may proceed simultaneously.

Breeding interval: Females of this species typically produce offspring every two years, and can produce yound twice in three years.

Range number of offspring: 1 (low) .

Average number of offspring: 1.

Range gestation period: 11 to 11.5 months.

Average weaning age: 5 months.

Range age at sexual or reproductive maturity (female): 4 to 5 years.

Range age at sexual or reproductive maturity (male): 4 to 5 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous

Average birth mass: 1.35e+06 g.

Average number of offspring: 1.

Calves are born in the warm tropical waters and subtropical waters of each hemisphere. Newborns are usually 4 to 5 m long, and are suckled by their mothers for about 5 months. The females' milk is highly nutritive, containing high amounts of fat, protein, lactose and water. There is no parental investment on the part of the males.

Parental Investment: pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)

In the western North Atlantic, young are born from December or January through March. Gestation lasts 11-12 months. Most adult females bear a calf every 2-3 years (sometimes 1 or 4 years). Young are weaned in 5-12 months. Twelve females that were monitored since first being observed as calves produced their first calves at ages of 5-7 years (Can. J. Zool. 70:1470). In Alaska, the age of first calving is 8-16 years (average 11.8 years).

Reaches sexual maturity around 4-5 years old. Total length of time devoted to calf, from gestation to end of lactation, is about 2 years.

Rounded Global Status Rank: G4 - Apparently Secure

Reasons: Large worldwide range extends throughout all oceans; depleted by past overharvesting; population size now exceeds 60,000 and has increased over the past several decades; vulnerable to marine pollution, disturbance by boat traffic, and entanglement in fishing gear, but these are not major threats, and the species is now apparently secure.

As of 1999, listed as an endangered species in the ESA. Humpbacks were heavily exploited commercially until 1963 when IWC protection started. Now protected by IWC, CITES, and CRW (mothers and calves, specifically). Population estimated around 25,000 worldwide.

As of 1999, listed as an endangered species in the ESA. Humpbacks were heavily exploited commercially until 1963 when IWC protection started. Now protected by IWC, CITES, and CRW (mothers and calves, specifically). Population estimated around 25,000 worldwide.

Classified as Least Concern (LC) on the IUCN Red List (1). Listed on Appendix I of CITES (4), and Appendix I of the Convention on Migratory Species (CMS or Bonn Convention) (5).

Global Short Term Trend: Increase of 10 to >25%

Comments: Populations have increased in the North Pacific, North Atlantic, and Southern Hemisphere over the past several decades (Stevick et al. 2003, Calambokidis et al. 2008, Reilly et al. 2008).

Humpback whales became one of the major targets of the whaling industry due to their coastal migration routes; it is estimated that over 100,000 humpbacks were slaughtered in the southern hemisphere alone, between 1900 and 1940 (6). Protected from whaling today, these whales are vulnerable to changes in the marine environment and are threatened by pollution and the possible alteration of fish stocks as a result of climate change (8).

Global Protection: Few (1-3) occurrences appropriately protected and managed

Needs: In waters off northeastern North America, more effective entanglement reporting and assisting systems are needed, and increased efforts are needed to decrease entanglements in fishing gear (Volgenau et al. 1995). Protection could be enhanced by establishement of additional marine sanctuaries in areas where the species congregates.

Humpback whales received full protection in 1966 and have since captured the public's imagination (6). Whale watching tours to see these magnificent animals are popular throughout the world from Alaska to Hawaii and Japan to Australia (2). In the northwest Atlantic particularly, these have worked closely with scientists providing valuable photo identification of individuals that has helped to uncover some of the mysteries surrounding their impressive migration (2). Humpback whales are the most studied of the large whales but little is still known about some aspects of their behaviour and about population dynamics (9), further research and monitoring is therefore needed to safeguard these awe-inspiring acrobats of the sea.

Humpback whales staying close to the shore on the Eastern Canadian seaboard damage cod and herring traps and can tear loose long lengths of a set net.

Negative Impacts: crop pest

Humpbacks have historically had incredible economic importance to humans. They were one of the nine species hunted intensively by whalers. They were at times the most important constituent of the catch of modern whalers. Their oil was in demand as a kind of burning oil for lamps and as a lubricant for machinery. Whale oil was also used as a raw material for margarine and as a component of cooking fat. Whale meat was processed for human consumption and made into animal feed. Meal made from whale bones was used as fertilizer.

However, these animals are no longer hunted extensively. They do continue to have some economic impact, as ecotourism and whale sighting tours are quite popular in appropriate coastal areas.

Positive Impacts: ecotourism

Comments: Humpback whales formerly were subjected to heavy commercial harvest, primarily for oil; a very small harvest for local use still occurs in the Lesser Antilles. Economic value today is primarily as objective of many whale watching cruises.

subpopulation Arabian Sea humpback whale : Endangered (EN)

subpopulation Oceania humpback whale : Endangered (EN)

Least Concern (LC)