Bowhead whale (Balaena mysticetus)
Facts
| Also known as: | Greenland Right Whale |
|---|
| Kingdom | Animalia |
|---|---|
| Phylum | Chordata |
| Class | Mammalia |
| Order | Cetacea |
| Family | Balaenidae |
| Genus | Balaena (1) |
| Size |
Length: 12 - 20 m (3) |
| Weight |
60 - 80 tonnes (2) |
Status
Classified as Lower Risk / Conservation Dependent (LR/cd) on the IUCN Red List 2007 (1). Listed on Appendix I of CITES (4), and Appendix I of the Convention on Migratory Species (CMS or Bonn Convention) (5). Subpopulations: The Spitzbergen population is classified as Critically Endangered (CR); Davis Strait-Baffin Bay population and Okhotsk Sea populations are classified as Endangered (EN); Hudson Bay-Foxe Basin population is classified as Vulnerable (VU) and the Bering-Chukchi-Beaufort Sea population are classified as Lower Risk / Conservation Dependent (LR/cd) on the IUCN Red List 2007 (1)
Description
The bowhead whale is so-called because of its bow-shaped mouth (7) and is black in colour with a whitish chin patch (6), broken by a 'necklace' of black spots (8). This whale lacks a dorsal fin and is usually visible as two bumps from above water, which correspond to the head and the back (8). The blow (or spout) is produced from the two widely spaced blowholes, and is a bushy V shape reaching seven metres in height (8). The baleen is dark grey to black in colour (6) and is the longest of any whale; sometimes measuring well over three metres in length (3). Females are larger than males, but otherwise the two sexes are generally of similar appearance (7).
Range
Habitat
Often found close to the edge of the Arctic ice shelf (6).
Biology
Amazingly, this whale is known to live to over 100 years of age, a fact established by the discovery of stone harpoon heads (out of use since the late 1800s) in the flesh of specimens. The diet consists of planktonic crustaceans, which are filtered through the baleen plates (7). Bowhead whales often skim-feed on the surface of the sea but also gather food from the sea floor.
To insulate against the cold Arctic waters, bowhead blubber may be 70 centimetres thick and the whales can break through ice of a foot deep to make breathing holes (3). Bowheads are slow breeders and maturity may not be reached for 20 years. A single calf is born every three or four years after a gestation period of about 13 months (3).
Threats
The main threat to this species has been hunting, particularly following the expansion of the whaling industry after the 1600s (7). Other current threats include entanglement in fishing nets and collisions with ships (8). Pollution, climate change and disturbance by tourists are also likely to be having a detrimental effect on this whale (3).
Conservation
In 1986 the worldwide moratorium on whaling came into effect, although small-scale hunting of this whale by the Inuit of Alaska continues under the guidance of the International Whaling Commission (IWC) (9). The population of bowhead whales appears able to absorb this low-level pressure however, and numbers are increasing in some areas (2).
Further Information
For more information on the Bowhead and other whales see:
- Carwardine, M., Hoyt., E, Fordyce., R.E., and Gill, P. (1998) Whales and Dolphins. Harper Collins, London.
- The Whale and Dolphin Conservation Society (WDCS):
www.wdcs.org/ - The Smithsonian Institution's North American Mammals website:
www.mnh.si.edu/mna/main.cfm?lang=_en
Authentication
Authenticated (19/08/02) by WDCS, The Whale and Dolphin Conservation Society.
http://www.wdcs.org
Baleen: In some whales, the comb-like fibrous plates hanging from the upper jaw that are used to sieve food from sea water. These are often referred to as whalebone.
Crustaceans: Diverse group of arthropods (a phylum of animals with jointed limbs and a hard chitinous exoskeleton) characterised by the possession of two pairs of antennae, one pair of mandibles (parts of the mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, slaters, woodlice and barnacles.
Dorsal fin: In fish, the unpaired fin found on the back of the body.
Gestation: The state of being pregnant; the period from conception to birth.
Plankton: Aquatic organisms that drift with water movements; may be either phytoplankton (plants), or zooplankton (animals).
References
- IUCN Red List (March, 2008)
http://www.iucnredlist.org - Macdonald, D. (2001) The New Encyclopedia of Mammals. Oxford University Press, Oxford.
- WDCS. (2002) Pers. Comm.
- CITES (March, 2008)
http://www.cites.org - CMS (March, 2008)
http://www.cms.int/ - UNEP-WCMC (March, 2008)
http://www.unep-wcmc.org/species/data/species_sheets/bowhead.htm - Animal Diversity Web (August, 2002)
http://animaldiversity.ummz.umich.edu/accounts/balaena/b._mysticetus$narrative.html - Carwardine, M., Hoyt, E., Fordyce, R.E. and and Gill, P. (1998) Whales and Dolphins. Harper Collins, London.
- International Whaling Commission (August, 2002)
http://www.iwcoffice.org
