'Spy cams' film polar bears up close
Several hi-tech cameras have cast new light on the world of the polar bear, in the icy Arctic islands of Svalbard in Norway.
Blizzard cam and snowball cam, iceberg cam and several drift cams were kitted out to withstand temperatures as low as -30C.
But to get the footage seen in Polar Bear: Spy on The Ice, they also had to be able to withstand the attentions of curious polar bears - including this mother, out of her maternity den with her new cub for the first time.
Polar Bear: Spy on The Ice is broadcast on BBC One at 2000 GMT on Wednesday 29 December - or afterwards on BBC iPlayer.