'Arctic unicorns' in icy display

Remarkable footage of elusive narwhal has been captured.

A BBC team used aerial cameras to film the creatures during their epic summer migration, as they navigated through cracks in the melting Arctic sea ice.
They believe the footage, which forms part of the BBC Natural History Unit's new series Nature's Great Events, is the first of its kind.
Narwhal are sometimes called "Arctic unicorns" because of the long, spiral tusk that protrudes from their jaws.

Click here to see this beautiful video.