There are two different types of beaked whales seen in our cruise to Niihau from the Napali Coast. They are the Blainville Beaked Whale (Mesoplodon densirostris) and less commonly, the Cuvier Beaked Whale (Ziphius cavirostris). Both of these species are rarely seen as they are reclusive animals that possess an extraordinary breath-holding ability. The sightings we do have tend to be brief although we've had encounters lasting for several minutes. These animals are deep diving, commonly staying under for 20-30 minutes while diving to depths of 1500 meters or more. When the animal does surface, it does so slowly and with little splashing. All of this points to an encounter being a rare and lucky experience.
The body of Blainville's Beaked Whale is thick top to bottom, but also somewhat compressed laterally (skinnier) compared with other Mesoplodonts. The males have a highly distinctive mouth: The jaw rising steeply about halfway along its length coinciding with two large, barnacle encrusted teeth. The flat melon of the whale is also a distinguishing characteristic. Coloration is a dark blue-gray on top and lighter gray on the bottom, and the head is normally brownish. Males reach at least 5 meters (18 ft.) and up to 1.5 tons, with females, generally speaking, slightly smaller.
The males are darker than females and often heavily scarred from combat with other males.
These are moderately social creatures, usually being seen in groups of 3-7 individuals.
The Cuvier's Beaked Whale has a short beak in comparison with other species in the family, making for a slightly bulbous-shaped melon. The melon is white or creamy in color and the white strip continues back to the dorsal fin about two-thirds of the way along the back. The rest of the body varies from individual to individual in color, some are dark grey, others a reddish-brown.
Cuvier's Beaked Whales are larger than Blainville's Beaked Whales, growing to around 7 meters long and weighting 2-3 tons.
Beaked Whales most likely feed primarily on squid and deep-sea fish.
See Australian Museum Online, "Blainville's Beaked Whale", http://australianmuseum.net.au/Blainvilles-Beaked-Whale/