Thursday, April 16, 2015

A-Z Blogging Challenge: Narwahls

So I was sick recently and spent a lot of time watching nature documentaries including one about a pod of orcas (better known as killer whales) that moves up the coast of the Canada into Arctic waters during the short Arctic summer where they prey on narwahls which have moved south to breed.

I had, of course, read about narwahls before and they are curious and fascinating creatures. It proved very difficult to find a clear photo so I had to settle for this drawing published in 1820 and now in the public domain. It's not a bad representation, though.

In: "An account of the Arctic regions with a history and description of the northern whale-fishery", by W. Scoresby. 1820. P. 588, Vol. II. Plate XV. Library Call Number G742 .S42 1820.

A member of the toothed whales, they are unique in having no teeth in their mouths. Adult males (and rarely females), though, have a long tusk, which can be close to three metres in length, and is formed from a canine tooth extending from the left upper jaw. It is straight with a spiral twist ending in a smooth polished tip. Why they grow this is unknown as is much else about the narwahl. Males average 4.1 metres in length (not including their tusk) but can reach 5.5 metres while females are slightly smaller, averaging 3.5 metres.
The beluga whale is the closest relative of the narwahl and that they spend their winters under the Arctic pack ice, gathering around fissures to breath. These fissures can close unexpectedly and leave the narwahls relying on them to suffocate.

Narwahls are predators that feed on mostly Greenland halibut, polar and Arctic cod, cuttlefish, armhook squid and shrimp. They are some of the deepest diving marine mammals diving between 800 and 1500 metres up to fifteen times a day and taking up to 25 minutes for each dive. They are believed to suck their prey into their mouths.

With only between 75-80,000 narwahls remaining they are regarded as near threatened and, although Inuits are allowed some subsistence hunting, trade in their ivory is banned in much of the world. Their future seems uncertain if the Arctic pack ice continues to melt and it will be sad if they disappear completely.


Donna McDine said...

Fascinating! Hope you are feeling better!

Helen V. said...

Thanks, Donna. I am a lot better now.