The existence of Arnoux’s Beaked Whale has only been known to mankind for a little over a century and a half.
During the mid 1800s, a whale skull was found in Akaroa Harbour, Banks Peninsula, New Zealand, by a ship’s surgeon named Dr. Maurice Arnoux.
This whale species was named after him in 1851.
Since then these marine mammals have also been spotted in Australia, the Indian ocean and the southern Atlantic ocean.
Arnoux’s beaked whale makes up one of over 20 known species of beaked whale.
The rest of this article will provide you with an overview of the information we’ve gathered an Arnoux’s beaked whale.
Physical Characteristics and Appearance
This type of whale is specifically known for its long, tubular beak and small head that features a steep forehead.
Because the whale’s lower jaw is longer than the upper, the bottom teeth of this whale are visible even when the animal’s mouth is closed.
Its body is slender, with the girth only being about half as much as its length.
Rough estimates regarding their size and weight put these whales at a measurement of up to 33 ft. long and 9 tonnes with children measuring around 12 – 14 ft. long.
Its flippers are rounded, small and located on the front of its body.
Its dorsal fin is also small and can be found toward the back of the body.
As this animal ages, the surface of its body picks up multiple white scars that can make it easier to identify.
The most identifying characteristic of the Arnoux’s Beaked Whale, however, is the presence of two pairs of erupted teeth in the lower jaw that occurs in both females and males.
They are sometimes called “four-toothed whales” or the “giant beaked whale’ due to their large size when compared to other beaked whales.
Diet and Hunting Methods
Scientists know very little about the particular diet of this type of whale.
It is most likely that they feast on marine life found primarily on the ocean floor, such as starfish, deep-water squid and sea urchins.
They may also feast on rockfish, octopus and sardines as well as various types of open water fish.
During deep dives these marine mammals have been observed holding their breath for up to an hour before resurfacing for fresh air.
Nothing is knwon about the strategies these whales use to obtain their food, however seeing as they only posses four teeth it is unlikely that their teeth play a major role in their ability to obtain food.
Social Structure and Reproduction
Arnoux’s Beaked Whales generally live in close-knit groups of between 6 to 10 animals.
However, groups as large as 50 whales have occasionally been reported.
In 1986, approximately 80 whales were observed in Robertson Bay, Antarctica.
Because these whales live their lives in deep waters, little is known about their mating and reproductive activities.
These animals are also shy and difficult to identify, making scientific observation challenging.
From the few observations obtained on these marine mammals they are known to occasionally breach the water.
Their reproductive habits are believed to be similar to that of Baird’s beaked whales, with males reaching sexual maturity at younger ages and smaller body weights than the female whales.
Unfortunately nothing is known about their verbal communication or social interactions so we are unable to elaborate further on this topic.
Habitat and Migration
Although Arnoux’s Beaked Whales are found throughout the southern hemisphere, they do not migrate to northern waters.
They have been seen near Antarctica, in the southern Pacific near Australia and New Zealand, in the Indian Ocean and the southern Atlantic Ocean.
During the summer, it is believed that they live close to the ice while going to more open waters in the winter months.
Summer sightings are frequent in Cook Strait, and large pods have been seen along the western coast of Antarctica during the spring.
However, even though this species has a wide geographical distribution in the southern hemisphere, it is not well-known or commonly found among that particular range, which indicates that its actual numbers are relatively small.
Due to limited information there are no estimates on potential population numbers, however it appears that most whales prefer living in cold environments with steep slopes in areas that are past the continental shelf.
Threats
Because the range of Arnoux’s Beaked Whales is so large and encompasses basically remote parts of the Earth’s oceans, commercial whaling is not and has never been a primary threat to this species.
Their numbers do not appear to be in danger of being reduced due to environmental conditions.
Due to their wide distribution and habitat these marine mammals face little threat from human involvement, however there have been raising concerns regarding loud man-made noises which can interfere with the whales communication and hearing.
In regards to natural threats some whales have been observed being trapped underwater by ice which can cause drowning as these animals are mammals and require air to survive.
Even though they can hold their breath for up to an hour there are circumstances where they can end up being unable to resurface due to large sheets of ice in some of the colder regions.
They are not listed as an endangered species, and only a small number of individual animals have been taken from the wild for the purpose of scientific study.
This is one of the most mysterious species of whale and also one of the most inaccessible to mankind, which is probably why its population remains stable.
Predators
Although information regarding potential predators of Arnoux’s beaked whale is unknown other beaked whale species have been known to be prayed up by killer whales and large sharks.
In situations where killer whales have been known to hunt whales they can often be seen hunting individual whales or using strategies to separate young whales from the adults when hunting in a group.
When it comes to sharks they are sometimes found hunting small whales or feeding on the carcass of already dead whales.