Deep dive...into Cuvier's beaked whales

The Cuvier’s beaked whale is one of the larger members of the beaked whale family. Found in most oceans and seas around the world, the species has the most extensive geographical range of all the beaked whales.

It has a long robust body with a dark grey back and sides, and much paler belly and head. It also has panda-like dark eyes around each eye. In some locations, the Cuvier’s beaked whale appears to have a brownish body because it’s covered in algae.

The profile of its head is conical and is sometimes described as ‘goose-like’, which lends them the name ‘goose-beaked whales’. The jaw-line is slightly upturned which gives them a ‘smiling’ appearance.

Like other beaked whale species, males have a pair of small cone-shaped teeth (resembling tusks) that come out of the tip of their bottom jaw, and are often used for fighting.

Scars on their bodies come from scrapes they get into during their active lifestyles and also bites from other animals (such as cookiecutter sharks) or from competing males of the same species. Their scarring patterns help researchers to identify individuals.

Cuvier’s beaked whales have a slightly bulbous melon, an indistinct beak and a small curved dorsal fin located far down their backs. They weigh between 1,800 and 3,000 kilograms and reach lengths of between five to seven metres.

As they get older, the whales become paler and develop more significant indentation at the top of the head.

It’s often hard to distinguish between the many species of beaked whales and they are also challenging to observe when at sea due to them keeping a low profile, spending only limited times at the water’s surface and their small, inconspicuous blow. Beaked whales are sometimes confused with the northern bottlenose whale.

When at the surface, the species doesn’t often breach but when it does, it’s been observed as being torpedo-like.

Cuvier’s beaked whales are the deepest and longest-diving marine mammals in the world. The deepest known dive for this species was 2.9 kilometres and the longest known dive lasted a whopping 3 hours 42 minutes!  This was recorded in 2020 – see this Science News article  for more.

They dive deep so they can feed on cephalopods (squid and octopus) that live in the further reaches of the ocean.

Cuvier’s beaked whales are usually found on their own or in small groups of around two to seven individuals. Though they prefer small groups, they are quite sociable animals. Global records show that Cuvier’s beaked whales are the most frequently stranded species amongst the beaked whales.

The whale gets its name from Georges Cuvier, who first described the species in 1823 from a skull found on a beach in southern France.

The species is found in temperate, subtropical and tropical waters. Cuvier’s beaked whales prefer deep pelagic waters and are found in most oceans and seas worldwide (except for the polar seas).

A lot of the information we have on their locations is from stranding records as opposed to sightings, as they are usually far out in the ocean and remain underwater for long periods. Little is known of their migration patterns.

They are usually found in areas including the Bay of Biscay, British Columbia, the Gulf of California, Mediterranean Sea, the Shetlands, the Gulf of Mexico, Massachusetts coastline, New Zealand, South Africa and Tierra del Fuego in South America. There have also been recorded strandings in the Bahamas, Caribbean Sea and the Galapagos Islands.

On the IUCN Conservation Red List of Threatened Species, the Cuvier’s beaked whale is listed as least concern. No global population figures exist but they are one of the most abundant of the beaked whale species.

Cuvier’s beaked whales are big fans of squid and eat at least 47 types of it! They also eat fish and crustaceans.

Since they don’t have teeth (apart from the two small tusks that males have), they use a suction method in their mouth using their ventral throat grooves. This allows them to slurp and suck in squid and other food.

As they are deep diving whales, one of the biggest threats to Cuvier’s beaked whales is noise emitted from a ship’s sonar. This confuses their echolocation which they use to find food, to navigate and to communicate.

The species can panic and surface too quickly if frightened by noise. In which case, they suffer decompression sickness, or ‘the bends’, just like human divers too.

It’s thought that mass strandings of the species could be linked with military activity underwater – this has been reported particularly in the Bahamas, Caribbean Sea and Mediterranean Sea. There were instances in the Canary Islands but since naval exercises using sonar were banned there, no further mass strandings have taken place.

Like other cetaceans, Cuvier’s beaked whales can become entangled in fishing gear which goes on to cause injury, fatigue, comprised feeding, and sometimes even death.

Cuvier’s beaked whales are at risk of vessel strikes throughout their range but the threat is much higher in areas with busy ship traffic.

Climate change and pollution are a threat to all whales and dolphins because of the loss of habitat as waters become warmer.

Plastics and micro plastics, along with chemical pollutants, entering into the water system are a serious threat to all creatures in our ocean.

As Cuvier’s beaked whales are suction feeders, they sometimes mistake plastic bags and other plastic materials for prey and ingest them. They can settle in their stomach, causing them to starve and die.

The species has been taken in Japanese whaling operations, usually opportunistically as part of a hunt for the larger Baird’s beaked whale.