Beaked whales are members of the family Ziphiidae, primarily distinguished in that the males all have enlarged teeth protruding from the lower jaw. Ziphiidae is the largest family of whales, and are found in all oceans except the Arctic; even so, among all of the Cetacea, they are the family of which we know the least. Some species are known only from a few stranded individuals, or in the case of Longman's beaked whale, only a few skulls. My Eyewitness Whale Handbook even has a listing for the 'Unidentified beaked whale', a possible species, without any scientific label. It is a beaked whale with unique and distinctive coloring, known from multiple sightings, but no one has been able to study a specimen, living or dead.

This lack of knowledge is in large part because beaked whales tend to live in the deep ocean trenches, and while they surface for longer periods than many whales (often for 10-15 minutes), they are discreet, with little of the breaching, lobtailing, and spyhopping demonstrated by many other whale species.

Beaked whales are medium sized whales, ranging from 3.5 (Lesser beaked whale) to 13 (Baird's beaked whale) meters in length, and 4400 to 11,500 kilograms in weight. They usually live in small pods (3-10 individuals). They seem to all eat squid; some have been observed to eat other deep-sea fish. Some, of course, have never been observed eating.

They usually have deep V-shaped grooves on their throats, a characteristic which is unique to the family Ziphiidae. This seems to be to provide space for the tongue to retract into; when done quickly, this creates suction, allowing the whales to feed by sucking up food. It's uncertain how much feeding takes place by this method, but as the teeth of beaked whales seem to be only for show and sparing (and usually entirely absent in females and the young) it may be the primary mode of feeding. In the Strap-toothed whale, the teeth actually grow around and over the upper jaw, preventing the mouth from opening properly; the males may be forced to feed exclusively through suction.

The teeth are generally the first thing to look for when identifying a beaked whale. As the young and females don't have these teeth, it is often impossible to identify which species they belong to when watching them in the wild. (The females do actually have small teeth, but they do not erupt from the gums, and are neither functional nor visible). The teeth may grow up to jut above the upper jaw, or stick out to the front like a shovel; in some species the protrusion of the teeth is enhanced by a bulging up of the jawbone, causing the upper jaw to sit in the deep saddle of the lower jaw. The teeth may be encrusted with barnacles and other sea-life, and in older males may be worn down to nubs.

Other identifying features of beaked whales are small dorsal fins and flippers, spindle-shaped bodies, the lack of a notch in the center of the flukes, and the afore-mentioned v-shaped throat grooves. Many, especially members of the genera of Berardius and Hyperoodon have bulbous foreheads, although others have little or no forehead.

There is great variation between individuals of the same species, making positive species identification difficult in the wild. Sexual dimorphism can be extreme, and often includes distinctive coloration (more common in the males), in addition to the teeth and overall size of the animal. Color can vary greatly among individuals (and in many species, most observed individuals have been rotting for a few days already, which doesn't help). Many of the markings seen on these whales are caused by scars caused by fighting among males, cookie-cutter sharks, and other parasites, and markings may be obscured by growths of algae.

Despite being comparatively hard to find, beaked whales are still hunted for their meat, oil, and spermaceti. Perhaps the most hunted species is the Northern Bottlenose Whale, which is attracted to the odd sounds that boats make, and the pod will try to stay with wounded members, making it easy to kill multiple individuals. But other species are hunted, and have been for hundreds of years. The Lesser Beaked Whale was only discovered in 1976, when a partial skull turned up in a fish market in San Andres, Peru. The first complete specimen was also found in a Peruvian fish market, in 1985.


All beaked whales seem to have four or five 'common names' each; I will only list the one or two most common. There is some debate about how many genera there should be, and what whales should go where. I have taken the taxa below from the site Animaldiversity*, as it seems to be an updated and complete one.

Order Cetacea
Suborder Odontoceti
Family Ziphiidae

Genus Berardius (Giant beaked whales)


Genus Hyperoodon (Bottlenose whales)

Genus Indopacetus (Longman's beaked whale)
(Sometimes placed in Mesoplodon)

Genus Mesoplodon (Beaked whales)

Genus Tasmacetus (Shepherd's beaked whale)

Genus Ziphius (Cuvier's beaked whale)

There are probably others that have not yet been discovered. The oceans are very big, and extremely cool places.


References:
Eyewitness Handbooks; Whales, Dolphins, and Porpoises, by Mark Carwardine.
http://www.nhm.org/research/mammals/suction.htm
http://animaldiversity.ummz.umich.edu/site/accounts/information/Ziphiidae.html
http://en.wikipedia.org/wiki/Beaked_whale
*http://animaldiversity.ummz.umich.edu/site/index.html
(http://animaldiversity.ummz.umich.edu/site/accounts/classification/path/Ziphiidae.html#Ziphiidae)

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