A pod of narwhals near Baffin Island, Nunavut, Canada

© Eric Baccega/Minden Picture

Hooray, hooray, it's Unicorn Day!

Today is Unicorn Day, known to its followers as ‘the sparkliest day of the year’. To honour the mythical horned beast, we bring you the next best thing: a pod of narwhals brandishing their tusks in the Arctic Ocean. Narwhals develop only two teeth, but - in males especially - the left canine can grow into a three-metre-long spiral tusk. As the tusk juts out of the top of their head, it's given the whale the nickname, 'unicorn of the sea'.

For centuries narwhal tusks were sold to gullible buyers as rare unicorn horns with magical powers. These 'unicorn horns' were so prized for their medicinal and healing properties that in the 16th century, Queen Elizabeth I paid around A$20,000 for one (equal to the cost of building a castle back then). By the late 17th century, scientific facts started replacing superstitious beliefs and the unicorn horn market fell out of favour.

Today narwhals continue to inhabit the deep waters of the Arctic and North Atlantic Oceans, surfacing in between cracks in the ice. Their long-term challenges will be associated with the loss of sea ice and environmental impacts from oil and gas development.