Monday, December 7, 2009

Did You Know...?

...the narwhal is the only animal whose name begins with the letter N.

Go ahead. Try to think of another animal that begins with N. I dare you.

And now for some fascinating narwhal facts:

The narwhal is a medium-sized toothed whale that lives year-round in the Arctic.

The most conspicuous characteristic of the male narwhal is its single 7–10 ft long tusk. It is an incisor tooth that projects from the left side of the upper jaw and forms a left-handed helix. About one in 500 males has two tusks, which occurs when the right incisor, normally small, also grows out. A female narwhal may also produce a tusk, but this occurs rarely, and there is a single recorded case of a female with dual tusks.

The most broadly accepted theory for the role of the tusk is as a secondary sexual characteristic, similar to the mane of a lion or the tail feathers of a peacock. This hypothesis was notably discussed and defended at length by Charles Darwin, in The Descent of Man, and Selection in Relation to Sex (1871). It may help determine social rank, maintain dominance hierarchies or help young males develop skills necessary for performance in adult sexual roles. Narwhals have rarely been observed using their tusk for fighting or other aggressive behavior or for breaking sea ice in their Arctic habitat.

Narwhals have a relatively restricted and specialized diet. Their prey is predominantly composed of Greenland halibut, polar and Arctic cod, shrimp and Gonatus squid. Additional items found in stomachs have included wolffish, capelin, skate eggs and sometimes rocks, accidentally ingested when whales feed near the bottom.

Narwhals exhibit seasonal migrations with high fidelity of return to preferred ice-free summering grounds, usually in shallow waters. In the winter, they are found primarily in offshore, deeper waters under thick pack ice, surfacing in narrow fissures in the sea ice, or leads. Feeding in the winter accounts for a much larger portion of narwhal energy intake than in the summer and, as marine predators, they are unique in their successful exploitation of deep-water arctic ecosystems.

Most notable of their adaptations is the ability to perform deep dives. When on their wintering grounds, the narwhals make some of the deepest dives ever recorded for a marine mammal, diving to at least 2,400 feet over 15 times per day with many dives reaching 4,500 feet. Dives to these depths last around 25 minutes, including the time spent at the bottom and the transit down and back from the surface.

Narwhals normally congregate in groups of about five to ten individuals. In the summer, several groups come together forming larger aggregations. At times, male narwhals rub one another's tusks together in an activity called "tusking". This behavior is thought to maintain social dominance hierarchies.

In Inuit legend, the narwhal's tusk was created when a woman with a harpoon rope tied around her waist was dragged into the ocean after the harpoon had struck a large narwhal. She was transformed into a narwhal herself, and her hair, that she was wearing in a twisted knot, became the characteristic spiral narwhal tusk.

Some medieval Europeans believed narwhal tusks to be the horns from the legendary unicorn. As these horns were considered to have magic powers, such as the ability to cure poison and melancholia, Vikings and other northern traders were able to sell them for many times their weight in gold. The tusks were used to make cups that were thought to negate any poison that may have been slipped into the drink. During the 16th century, Queen Elizabeth received a carved and bejeweled narwhal tusk for £10,000—the cost of a castle. The tusks were staples of the cabinet of curiosities.

The truth of the tusk's origin developed gradually during the Age of Exploration, as explorers and naturalists began to visit Arctic regions themselves. In 1555, Olaus Magnus published a drawing of a fish-like creature with a horn on its forehead, correctly identifying it as a "Narwal." Herman Melville wrote a section on the narwhal in Moby Dick, in which he claims that a narwhal tusk hung for "a long period" in Windsor Castle after Sir Martin Frobisher had given it to Queen Elizabeth.

In November 2009, Harvard University received $225,000 in "stimulus funding" under the American Recovery and Reinvestment Act of 2009 for a study that seeks to explain the function of the narwhal's tusk in the high Arctic.



  1. I was on the phone with Jen while looking at your blog, and she and Dave came up with the following: nuthatch, nautilus, naked mole rat, nightingale, newt, nightcrawlers, nurse shark.

  2. Oh yeah, I meant ASIDE from those. :P

    JK!! Those are some good ones. Good job!

    I wondered about it on and off all weekend and I seriously couldn't think of ANY except narwhal (and that one was Jason's)! I'm not sure what a nuthatch or a nautilus is (I can look 'em up).

  3. I can't take credit for any of them. A nuthatch is a little bird that climbs/hops up and down the trunks of trees, sometimes upside down. Not sure if you have them in the PNW.

    I didn't know a nautilus, either. It's some kind of sea mollusk or something.

  4. Well, that's why Jen has a PhD, she's a smartypants. ;)

    Nuthatch sounds familiar, my mom must have talked about them when we were in NYC (since she's a birdwatcher). Nautilus sounds more like a brand of car!