Blainville’s beaked whale (Mesoplodon densirostris)
|French:||Mésoplodon De Blainville|
|Spanish:||Ballena De Pico De Blainville, Zifio De Blainville|
|Size||Length: 4.7 m (2)|
Length at birth: 2 – 2.5 m (3)
|Weight||up to 1030 kg (3)|
Blainville’s beaked whale is classified as Data Deficient (DD) on the IUCN Red List 2004 (1) and is listed on Appendix II of CITES (4). It is also listed on Appendix II of the Berne Convention on the Conservation of European Wildlife and Natural Habitats (5), on Annex IV of the EC Habitats Directive (6) and on Schedule II of the Indian Wildlife Protection Act 1972 (7).
A particularly easy species to identify, Blainville’s beaked whale has two distinctive horn-like teeth that grow from bulges in the lower jaw, and may be encrusted with barnacles. The forehead is flattened and the lower jaw is arched, giving the head a similar appearance to the right whale. Blainville’s beaked whale is dark blue-grey above, and light below, with a darker dorsal fin and eye patch. Females develop white upper and lower jaws, and both sexes have large white spots covering the entire body. Males are heavily and deeply scarred from fighting, as well as from attacks by the cookie-cutter shark, which leaves characteristic marks (2).
Found in tropical and temperate latitudes in the Atlantic, Indian and Pacific Oceans as well as the Mediterranean and Black Seas (1).
Blainville’s beaked whale seems to avoid coasts, but little is known of its habitat preferences. It is distributed throughout tropical and subtropical waters (2).
Found in groups of three to seven, Blainville’s beaked whale both avoids and approaches boats. It performs shallow dives, as well as deeper dives lasting up to 45 minutes. On surfacing, the beak appears first, pointing vertically upwards, and after taking a breath, the beak is slapped against the water surface. The whale has also been noted as rolling slightly before diving (2). It feeds on fish and squid (8), locating its prey by echolocation (9). Nothing is known of its reproductive biology, although calves have been seen in spring (2).
The threats to Blainville’s beaked whale are poorly understood, but it is known to be susceptible to high intensity, low frequency, active sonar used by US and NATO vessels. This brings about acoustic trauma and results in strandings, thought to be caused by surfacing too quickly. It is also at risk from the ingestion of rubbish, as well as incidental catch and low levels of hunting (2).
No conservation action has been targeted specifically at this species, but its inclusion on the Berne Convention, the EC Habitats Directive and CITES (Convention on International Trade in Endangered Species of Flora and Fauna) give it some protection. Further research into the distribution and population of this distinctive species is necessary before an action plan can be drawn up.
For further information on this species see the CMS Report:
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
IUCN Red List (February, 2005)
CMS Report (February, 2005)
Sea Map (February, 2005)
CITES (February, 2005)
Berne Convention on the Conservation of European Wildlife and Natural Habitats (February, 2005)
EC Habitats Directive (February, 2005)
Indian Wildlife Protection Act 1972 (February, 2005)
Blainville's Beaked Whale - Mesoplodon densirostris - MarineBio.org (February, 2005)
- Johnson, M., Madsen, P.T., Zimmer, W.M.X., de Soto, N.A. and Tyack, P.L. (2004) Beaked whales echolocate on prey. Proceedings of the Royal Society of London Series B - Biological Sciences, 271: 383 - 386.