Narwhal

The rarest of whales, the Narwhal—"unicorn of the ocean"—has two teeth, one of which can grow more than nine feet long in the male. The tooth is sensitive to temperatures and chemicals in the water and scientists think it enables males to find food as well as females ready to mate. Narwhals dive deeper than any whales—as deep as 5,000 feet—and stay under for 25 minutes before surfacing for air.

The Narwhal lives mainly in the Atlantic Arctic. Because of specialized habitat, narrow range and limited diet (Arctic cod and halibut), it is one of the Arctic species most vulnerable to climate change. The Narwhal breeds in bays and fjords, moving offshore during winter to areas of heavy ice pack, breathing through the few cracks. Sudden or extreme temperature change can cause these cracks to freeze shut, trapping the whales. Other threats are illegal hunting, industrial activities, and risks from oil development, exploration and shipping in the Arctic.

Other animals at risk

Whooping Crane
The tallest bird in North America, the Whooping Crane is able to fly 500 miles a day. Some young cranes hatched in captivity learned their migration routes by following ultralight air craft.

Adelie Penguin
Even though they can't fly, to avoid predators Adélie Penguins are able to leap almost ten feet out of the water and land safely onto rocks. They follow the sun from their breeding colonies to winter feeding grounds, travelling an average of 8,000 miles a year.

Beluga
Belugas make such a variety of sounds—clicks, twitters, whistles, and mimics of other sounds—they have been nicknamed "sea canaries." As much as 40% of their body mass is blubber, which stores energy and keeps them warm in temperatures as low as 0 °C. The smallest whale on the planet, a baby Beluga gains up to 200 pounds a day.

Common Clownfish
All Clownfish are born male but some will switch gender to become the dominant female in a group. For protection, they hide among anemone, immune to their poison.