Cuvier's Beaked Whale

## Description

The Cuvier's beaked whale or goose-beaked whale (Ziphius cavirostris ) is the most widely distributed of all beaked whales in the family Ziphiidae. It is smaller than most baleen whales yet large among beaked whales. Cuvier's beaked whale is pelagic, inhabiting waters deeper than 1,000 feet (300 m). It has the deepest and longest recorded dives among whales at 9,816 feet (2,992 m) and 222 minutes respectively, though the frequency and reasons for these extraordinary dives are unclear. Despite its deep water habitat, it is one of the most frequently spotted beached whales.

The species was named *Ziphius cavirostris* by Georges Cuvier, based on a skull fragment which he believed to be a fossil from an extinct species. He reused the genus name *Ziphius* from an undetermined species mentioned by historical sources. The species name *cavirostris* from Latin *cavus* "hollow" and *rostrum* "beak", refers to a bony structure (cavity) anterior of the nares (the bones of the nose), now known as the prenarial basin. It is now known to be unique to males of this species.

## Appearance

Cuvier's beaked whale is widely distributed in offshore waters of all oceans. The color of their skin may vary greatly from individual to individual, though usually it ranges from dark slate-grey to rusty brown. As the animals age, the color on their head, neck and back lightens, which is more noticeable in male individuals. Thus, the skin color of head in old males seems to be almost entirely white. In addition, adult males of this species are easily identified by two large, cylindrical teeth, incongruously projecting from the tip of their lower jaw. In 1823, the French naturalist Georges Cuvier took a fragment of skull for a fossil, describing it as an extinct whale species. Then, several decades after the scientist's death, the 'extinct species' turned out to be a living and widespread mammal, today known as Cuvier’s beaked whale.

## Distribution

The species occurs throughout the world, inhabiting temperate, subtropical, and tropical waters of most of the world's seas and oceans. Cuvier's beaked whales live in the open sea, normally greater than 3,300 feet (1,000 meters) of the continental slope and edge. They can be found around banks, seamounts and submarine canyons. A scientific survey has shown that these animals also frequent currents, current boundaries, and core ring features. Currently, there is no information about the migration habits and seasonality of this whale. According to the recently conducted genetic diversity studies, the animals normally remain within the basin of their 'home' ocean.

## Behavior

These wales usually occur in groups of 2 - 7 animals, though some animals, mostly males, can be found alone. Cuvier's beaked whales do not tend to show active behavior such as breaching, when they are at the surface. The blow of this animal is hardly seen; it occurs with intervals of 20 - 30 seconds, pointing to the left and a bit forward while reaching 3 feet (1 meter) in length. When the whale swims, the body and the head of the animal emerge from the water. In order to feed, this deep diver is able to dive more than 3.300 feet (1.000 meters), remaining submerged for up to 85 minutes per time. Before a deep, vertical dive, Cuvier's beaked whale arches its back more than usually, showing its flukes. Hunting in the lightless depths, the animal uses echolocation to detect potential prey.

## Diet

Cuvier's beaked whales are carnivores (molluscivores). Their diet primarily consists of squid, supplemented with fish and occasional crustaceans.

## Reproduction

Presently, quite a little is known about the reproductive behavior of these whales, since the animals are rarely seen at sea. They are likely to breed and give birth throughout the year with peak period, occurring in spring. Females give birth with an interval of 2 - 3 years. Gestation period lasts for a year, yielding a single calf. Males are sexually mature when they are 18-20 feet (5.5-6.1 m) long, whereas females - 20 feet (6.1 m) in length, which corresponds the age of 7 - 11 years.

## Population

### Population threats

Along with other whale species, these animals are threatened by a number of factors, including global climate change as well as heavy metal and pollution intoxication. Cuvier’s beaked whales are incidentally caught in fishing gears. At this point, there have been known 41 cases of mass strandings of these whales, that are, probably, only a small part of all dead animals, considering that those dying in the offshore waters are hardly washed ashore. Meanwhile, some of these mass strandings occurred simultaneously with naval manoeuvres, which included use of active sonar, which leads to conclusion that some sonar sounds can be dangerous or fatal for Cuvier’s beaked whales.

### Population number

According to the IUCN Red List, the global population size of the Cuvier’s beaked whale is likely to be well over 100,000 individuals, including estimated populations in the following areas: in the eastern tropical Pacific - 80,000 whales; off the U.S. west coast - 1,884 whales; in Hawaiian waters - 15,242 whales. Currently, Cuvier’s beaked whales are classified as Least Concern (LC) on the IUCN Red List.

## Fun Facts for Kids

Cuvier's beaked whale is one of the most commonly seen beaked whale species around the world.

As common in beaked whale species, Cuvier's beaked whale is a timid animal that typically avoids research vessels and other ships.

Cuvier's beaked whale has the most widespread range and distribution of all whale species in the world.

Cuvier’s beaked whale is also the deepest diving mammal in the world, able to dive at a depth of approximately 10,000 feet (3, 048 meters). Moreover, a study, conducted in 2014, has shown that this animal is the longest known mammal to hold its breath under water.

Cuvier’s beaked whale is able to remain submerged for up to 90 minutes, though, according to some scientific studies, the animal can dive for as long as two hours.

Cuvier’s beaked whale usually sleeps at the top of the water so that the blowhole of the animal is above the sea surface. From time to time, the animal comes to the water surface, quickly blowing air out of the special blowhole; releasing air makes a stream of watery mist known as a "blow".

## References

https://animalia.bio/cuviers-beaked-whale