Humpback Whale

Common Name: Humpback Whale

Class: Mammalia

Order: Cetacea

Family: Balaenopteridae

Genus: Megaptera

Species: Megaptera novaeangliae

Taxonomy/Description

Humpback whales belong to the Mammalian Order Cetacea, in the suborder Mysticeti.  All baleen whales belong to the suborder Mysticeti, which is Latin for "mustached whales".  The humpback whale belongs to the rorqual family, Balaenopteridae.  The word "rorqual" means "tube whale or furrowed whale", referring to the pleats on the lower jaws of rorquals.  All rorquals have baleen, a dorsal fin and throat grooves.  Other members of this family include the blue whale, fin whale, and minke whale.  The humpback whale's scientific name is Megaptera novaeangliae.  Its generic name, Megaptera, means "large fins", which refers to the humpback whale's extremely long pectoral fins.  These fins are extremely long, growing as long as one third of the whale's entire body length.  The humpback whale's specific name, novaeanglinae, means "New England".  The first specimen of this species was identified off the coast of New England.  The common name "humpback" refers to the whale's odd posture.  Its body is angled, with its head and flukes pointed downward.  The back arches upward, giving a humped appearance.  Humpbacks grow to lengths of 40-50ft and weights of 25-40 tons.  Females are slightly larger than males.  This species is easily recognized by its very large, white pectoral fins.  The fins are very knobby on the posterior side.

Habitat/Diet

Humpback whales are found in all oceans.  Their major food sources are krill and small fish.  Quantities of food greater than one ton are consumed each day.  As the whale opens its large mouth to gulp up its prey, the pleats of its lower jaw expand to contain the large volume of water.  The whale then presses it tongue up against the roof of its mouth, straining the water through its 250-400 baleen plates.  These 30 inch plates are composed of keratin, the same substance of fingernails and hair.  The ends of baleen are brush-like, preventing the fish or krill from escaping.  The prey remains inside, and are consequently swallowed.

Reproduction/Behavior

Humpback whales engage in a variety of acrobat behaviors.  Fluke slaps, fin slaps, and breaching are all characteristic of humpback whales.  These aerial shows are quite genuine, because it is rare for large animal species to engage in such behaviors.  Some researchers believe these displays are a type of communication between whales.

Most scientists agree that humpback "singing" is a communicative behavior.  This species of whale is famous for its 10-20 minute vocal displays, which travel miles away from the singer.  Humpback songs differ between regions.  The songs change slightly within the population from year to year.  Since solitary males perform the songs, scientists infer this behavior advertises availability to receptive females.

Humpbacks migrate annually.  Summers are spent feeding in cooler temperate and arctic waters.  Winters are spent calving and breeding in tropical waters.  Bulls compete by thrashing their tails and pushing one another to get closer to a receptive female.  After a 12 month gestation, a 10-15ft long, one ton calf is born.  It nurses for about one year, but will remain with its mother for longer.

A very interesting humpback behavior is called "bubble netting".  This is characterized by a hunting group of humpbacks releasing streams of bubbles from their blowholes while underwater.  The bubbles confuse schooling fish, which react by clumping close together.  The bubbles scare the school towards the water surface.  The fish are trapped at the surface and the humpback pod attacks the fish from below.

Conservation

Humpbacks were hunted by whalers once the larger species of whales became depleted.  As slow swimming, shallow water animals, humpbacks were very easy targets.  The International Whaling Commission banned humpback hunting in 1966.  They are protected under the United States' Marine Mammal Protection Act of 1972 and the Endangered Species Act of 1973.  The humpback population is currently recovering, and is estimated between 30,000 and 40,000 individuals.


 

Content provided by Canisius College students under the direction of Michael Noonan, PhD.