Southern Bottlenose Whale

The southern bottlenose whale measures 7.5 m (25 ft) in length when physically mature, considerably smaller than the northern bottlenose whale. The beak is long and white in males but grey in females. The dorsal fin is relatively small at 30–38 cm (12–15 in), set behind the middle of the back, falcate (sickle-shaped), and usually pointed. The back is light-to-mid grey. It has a lighter underside. There is currently no evidence to support sexual dimorphism in coloration. More data need to be collected to understand if coloration differences are individualized or based on geographic range.

The southern bottlenose whale has a circumpolar distribution in the Southern Ocean.They live in remote environments beyond continental shelves in water deeper than 1,000 meters.

It is found as far south as the Antarctic coast and as far north as the tip of South Africa, New Zealand's North Island and the southern parts of Brazil.

Sightings of bottlenose whales in tropical and subtropical waters were likely not of southern bottlenose whales; rather they were of a poorly known species, Longman's beaked whale.

The southern bottlenose whale feeds mainly on squid. Recorded taxa include Histioteuthis eltaninae and H. meleagroteuthis, Taonius pavo, Gonatus antarcticus, Moroteuthopsis ingens and M. longimana, Chiroteuthis sp., Galiteuthis glacialis, Martialia hyadesii, Alluroteuthis antarcticus, Filippovia knipovitchi, Psychroteuthis glacialis, and Liocranchia sp. Other prey include krill, some fish (Patagonian tootfish) and tunicates. Interestingly, remains of juvenile, subadult, and possibly mature colossal squid have been recorded in the stomachs of some individuals, with estimated mantle lengths up to ~120 cm and weights up to ~13.8 kg; the species’ rotating hooks may also contribute to the extensive scarring observed. How they capture these large cephalopods is unknown.

Dive times range from 15 to 40 mins, which is a long dive time relative to other cetaceans, and occur in small group sizes between 1-5 individuals. As typical for beaked whales, adult males tend to have extensive white scarring throughout the body, typically presumed to be the result of intraspecific aggression. Some scarring is also suggested to have been caused by squid suckers.

The global population is unknown. Population estimates are lacking; however, southern bottlenose whales accounted for more than 90% of ziphiid sightings in the Antarctic Circle.