|Humpback Whale, Megaptera novaeangliae Common Names: Humpback Whale, Humpback, Hump whale, Hunchback Whale
General Description: A large baleen whale, Humpbacks can reach up to 16m in length. They are black with variable amounts of white on their underside. They are easily identified by their long pectoral fins. These fins are scalloped on the forward edge and can be one third of the length of the whales body. Large fleshy knobs on the head and jaw of the animal are another distinguishing feature. The flukes (tail fins) have a serrated rear margin which is divided by a deep notch. The underside of the flukes is often seen when humpbacks descended for a dive. The black and white colouration pattern on the underside is unique to each whale and can serve as an excellent means of identification. The whale’s common name is derived from the hummock or “hump” upon which the dorsal fin rests. Often seen breaching, lobtailling or flippering, a visual siting is the only way to be sure of their presence in a region.
Geographical Distribution & Habitat Requirements: Humpback whales once had a cosmopolitan distribution but are now restricted in their range. Currently, northern populations are found in the Northwest Atlantic and the Northeast Pacific. In New Brunswick, humpback whales are found in the Bay of Fundy during the summer monthes. Humpbacks spend their summer monthes in high latitude feeding grounds that are characterized by upwelling and high productivity. During the winter monthes, they are found in warm and shallow tropical waters often among coral reefs.
General Biology: Humpback whales migrate between high latitude feeding grounds and low latitude breeding grounds. The populations off the east coast of Canada spend their winters in the West Indies. Different groups of humpbacks will congregate together for breeding and divide up into smaller groups when they move to their feeding grounds. A groups will always return to the same feeding ground year after year.
Feeding grounds are located in coastal shelf regions and offshore banks. These regions are well stocked with many of the small fish that the humpbacks like to feed on such as capelin, herring, anchovies and sand lance. Other common food sources are krill and plankton. Humpback whales are filter feeders. Rather than teeth, they have long rows of flexible, horny plates suspended from their upper jaw. These plates are fringed with hair like projections that create a filter.
Breeding occurs in shallow, tropical waters between January and March. Females give birth to a single calf every 1-4 winters after a one year gestation period. The calf will stay with the mother for a minimum of nine monthes during which it rarely strays more than 1m from its mother. Weaning occurs just prior to or shortly after migration. Sexually maturity is reached at 11-12m. Humpback whales are known for their haunting song. They produce both melodic songs and harsh gurgling noises. Males sing primarily during the breeding season in an effort to attract mates. Vocalization appears also to be used as a form of communication within pods of whales. It has been suggested that different groups have slightly different songs.
Conservation: Humpback whales were extensively exploited in the 1800s and early 1900s. The North Atlantic Humpback whale population received full protection in 1955 from the International Whaling Commission. As of 1996, Humpback whales were listed as vulnerable on the IUCN Red List. However, they currently appear to be making a comeback. A recent large scale mark-recapture survey of the North Atlantic population was conducted and the population is currently estimated at 10 600. This number is well above previous estimates of 3000.