Sowerby’s beaked whale, like other beaked whales, is extremely hard to observe due to its deep offshore habitat, its long dive times, similarities in appearance with other beaked whales, and its inconspicuous blows at the surface (8). As a consequence, little is known about the social structure of Sowerby’s beaked whale, although it has been observed in groups of three to ten (4) (8), with groups consisting of both males and females (4).
Knowledge of the diet of Sowerby’s beaked whale is limited, but studies have suggested that it may consist primarily of deep sea fish, including Atlantic cod (Gadus morhua), as well as squid (1) (9). To reach the habitat of its prey, Sowerby’s beaked whale must make deep dives, and its dive time has been observed to be between 12 and 28 minutes long (4) (8). Like other beaked whales, Sowerby’s beaked whale has a pair of external grooves on the throat which allow the mouth floor to be distended, creating a vacuum that sucks prey into the mouth. The prey is then swallowed whole (2).
As in other beaked whales, competition between males over mating rights is probably common, and male Sowerby’s beaked whales may use their teeth, or tusks, in confrontations. This would help explain observations of significant scarring down their bodies (10).
The breeding season of Sowerby’s beaked whale is thought to be late winter to spring (3). Like all cetaceans, Sowerby’s beaked whale gives birth to a single calf at a time, and this species is believed to have a 12-month gestation period (2).