Mesoplodon densirostris

Description: 

Blainville’s beaked whale is one of the species of the genus Mesoplodon the most widely distributed: they are in fact recorded from tropical and warm temperate seas of all oceans. They can be more easily identified than other beaked whale species thanks to its high arching prominence near the corner of its mouth. At its root, adult males have a pair of massive triangular and flattened teeth which are then encrusted with barnacles.

 

Physical description and behaviour:

The species’ body colour tends to be dark bluish grey or black. They are often a lighter grey on the abdomen and commonly has large grey or pale blemishes on the upper surface of the body.

Their head is flattened in front of the blowhole and their beak is slender and moderately long. Their body has the typical shape of its genus although adults reach lengths of 4m to 5m, which is smaller than Sowerby’s beaked whale.

Little is known regarding their behaviour. However previous research provided insights on their foraging behaviour using echolocation. Indeed, their echolocation process when hunting can be divided in three phases (search, approach, terminal) similarly to echolocating bats (Madsen et al., 2005)

 

Distribution and abundance:

The species has mostly been recorded in the Gulf of Mexico, the Caribbean and the south eastern United Stated although a few sightings also occurred between Novia Scotia and southern Brazil. In the north east Atlantic, Blainville’s beaked whale has been recorded mainly in the Canaries where they are quite frequent but also in Spain, Portugal and Madeira.

 

IUCN Red List of Threatened Species™ Assessment

  • LC (Least Concern) globally, last assessed in 2020
  • DD (Data Deficient) in European waters, last assessed in 2007

 

Threats:

Underwater noise disturbances such as mid-frequency active sonar are thought to be the main threat impacting Blainville’s beaked whales. They indeed change their behaviour during mid-frequency active sonar operations such as in the Bahamas (McCarthy et al., 2001). A highly significant co-occurrence between the use of mid-frequency active sonar and beaked whales’ strandings has also been detected between 2006 and 2019 in the Western Pacific Ocean (Simonis et al., 2020).

 

Assessment information
CMS InstrumentsASCOBANS, ACCOBAMS, Western African Aquatic Mammals, Pacific Islands Cetaceans
IUCN StatusLeast concern

No pictures for Mesoplodon densirostris

Common names
EnglishBlainville's Beaked Whale
Taxonomy
ClassMammalia
OrderCetacea
FamilyZiphiidae
Scientific name Mesoplodon densirostris
Other details
Additional notesUpdates have been made in August 2021 as per European Whales, Dolphins and Porpoises by Peter G. H. Evans (2020) unless stated otherwise.