North Atlantic Bottlenose Whale

When physically mature, northern bottlenose whales can reach 9.8 metres (32 ft) in length, smaller than giant beaked whales, and larger than known records of southern bottlenose whales. Their foreheads, or melons, are sexually dimorphic, so that mature males have larger melons, which are flattened or square shaped, while mature females and juveniles have rounder melons. Melon coloration can vary, though it appears the head of most males becomes more white or buff colored with age. The beak is not as long as other beaked whale species, and only mature males have two small teeth, which erupt at the front end of the bottom jaw, but are not easily seen. Females also have teeth, but they are buried in the jaw and do not erupt. The dorsal fin is relatively small, at 30–38 centimetres (12–15 in) and about two thirds of the way back on their bodies.

The northern bottlenose whale is endemic to the North Atlantic Ocean and populations are found in the deep (>500 m) cold subarctic waters of the Davis Strait, the Labrador Sea, the Greenland Sea and the Barents Sea, but can range as far south as Newfoundland and Nova Scotia. As of 2017, the population in the North East Atlantic is estimated to be between 10,000 and 45,000. However their population number is very poorly understood.

"The Gully", a large submarine canyon east of Nova Scotia, is the home of the "Scotian Shelf" population of 164 whales, currently listed under Canada's Species at Risk Act as endangered. This population is the focus of a long-term research project conducted by the Whitehead Lab, at Dalhousie University since 1988.

Northern bottlenose feed mainly on deep water squid, primarily Gonatus fabricii and G. steenstrupi, and bottom fish, such as Greenland halibut. Foraging dives can last an hour or more at depths reaching over 1000 meters. A small percentage of northern bottlenose whales have also been observed feeding on redfish, rabbitfish, spiny dogfish, and skate. Other recorded prey include Taonius pavo, Brachioteuthid squid, vampire squid, Teuthowenia megalops, prawns, sea cucumbers, common ling, echinoderms, and Sebastes sp.

Unlike many species of beaked whale, northern bottlenose whales are known to approach and appear curious about vessels, which made them relatively easy targets for whale hunters. However they have demonstrated avoidance to certain sounds such as those emitted by naval sonar in controlled dose response studies.

Underwater recordings have found that northern bottlenose whales produce regular high frequency clicks in click trains, which have a characteristic frequency modulated pulse or "upsweep", commonly found in other species of beaked whales. Northern bottlenose whales live in social groups, and are typically found at the surface in groups of 4 to 20.

Prior to the beginning of whaling, it is estimated that there were upwards of 100,000 northern bottlenose whales in the North Atlantic. Between 1850 and 1973, commercial hunting of the species, focused on populations found off Norway, Iceland, Greenland and Labrador, greatly reduced their numbers across their range. Current conservation concerns include threats from human activities such as disturbance related to offshore oil and gas developments and naval sonar, as well as entanglement in fishing gear, pollution, ingestion of plastic and ecosystem shifts related to climate change.