Andrews' beaked whale

Andrews' beaked whale, also known as the deep-crest beaked whale or splay-toothed whale, is a medium-sized cetacean that remains one of the least understood species within its genus. All current knowledge about this whale is derived from specimens that have washed ashore, as it has never been observed alive in its natural habitat. Its existence was first documented in 1908 from a specimen found in New Zealand.

Taxonomy and Description

The species was named by American scientist Roy Chapman Andrews in honor of George S. Bowdoin. Andrews' beaked whales are characterized by a robust, spindle-shaped body, a low melon, and a short, thick beak. Adult males are distinguished by a pair of large, flattened tusks that erupt from their arched lower jaws. These tusks are absent in females, whose teeth remain unerupted in a less-arched jawline. Adult males are typically dark brown or black with a contrasting pale lower jaw and rostrum tip, while females exhibit a bluish-gray to slate grey dorsal surface that fades to paler sides and underside, also sharing the pale lower jaw and rostrum tip. Both sexes may possess a small, pale patch in front of the eye. Calves are dark on their dorsal side and light ventrally, with a noticeable dark eye patch. Their flippers are small and narrow, set low on the body, and accompanied by 'flipper pockets' that aid in streamlining during dives. The dorsal fin is small, triangular, and positioned far back on the body, and their flukes are broad with a typically indistinct median notch.

Behavior and Ecology

Andrews' beaked whales are presumed to be deep-diving, echolocating suction-feeders. Like other beaked whales, they possess V-shaped throat grooves that likely assist in creating negative pressure within the mouth, drawing prey inwards. While precise dietary information is lacking, it is believed they prey on deep-sea squid and fish. Socially, they may form small pods of one to five individuals. Adult males often display extensive, linear pale scarring across their bodies, which is thought to result from tusk use in male-male combat, potentially for access to females. The calving season may occur during the summer and autumn months off New Zealand, though other behavioral aspects remain largely unknown.

Distribution and Conservation

Andrews' beaked whales inhabit the Southern Hemisphere, though their exact range is uncertain. Stranded specimens have been reported in Australia, New Zealand, Macquarie Island, the Falkland Islands, and Tristan da Cunha, suggesting a possible circumpolar distribution. This species has never been hunted, nor are there records of it being incidentally caught in fishing gear. Andrews' beaked whale is also protected under the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region.