Book review: Narwhals

Narwhals: Arctic Whales in a Melting World
by Todd McLeish
2013

Todd McLeish gives us a great introduction to a striking animal.

While most everyone knows about narwhals, all we remember it for is the tusk.  As striking as that tusk or horn is (it's a giant tooth, essentially, but one that grows in a unique spiral pattern), there's a lot more to the animal than that. 
The author recounts his travels to see narwhals in North America, Greenland, and Iceland. He speaks with biologists, indigenous hunters, and various other folks. Narwhal hunting is legal, though regulated, and the tusks are still prized worldwide by collectors of natural history items.  (The tusks cannot be imported legally into the U.S., though a Canadian dealer told the author it could be arranged.)  Narwhals are still important sources of meat and muktuk and other useful items in the far North. McLeish  attends hunts and, while a confirmed animal lover, is not opposed to controlled hunting in communities where the animal is an important food source and the entire carcass is put to use.
Now, about that tusk...The males, we learn, do not use their seven-foot tusks to joust or for defense. They do have an odd habit of raising their tusks into the air in pairs or groups, like knights hoisting their lances after a tournament, and sometimes touching them together.  (About one half of one percent of narwhals have two tusks, and occasional tusked females are reported.)  McLeish also reports on the controversy about what the tusk is for. It's not for grubbing up food or for breaking through ice.  Most cetologists regard it as strictly a sexual display item, like antlers, but a few researchers point to what appear to be nerve channels (this tooth is, compared to your teeth, essentially inside out) and think it has important functions as a sensor probe, testing water temperature and salinity in ways that might help males find females. 
Narwhals are not endangered, with a population of 80,000 or so, but they face unknown effects from climate change and the accumulation of PCBs and other toxins.  They are, McLeish argues convincingly, worth protecting as a part of the Arctic ecosystem and as a species admirably adapted to harsh conditions where even other whales are rare.
There are a couple of subjects I hoped the author would touch on to make this a more comprehensive book on the species. One is the hybridization of narwhals and belugas, which is rare but a confirmed fact. The other is the strange reports of narwhals or something like them from the opposite end of the Earth: a southern narwhal, while reported only a couple of times, is still an interesting topic. 
Despite these small omissions, this is a terrific book. I read it through at one sitting, and and I now know a lot more about these unique cetaceans and their world.