London: When the polar bear was born in Scotland just before Christmas - the first in Britain in 25 years - zoologists could confirm the occasion only because of the high-pitched sounds coming from the mother's den.

Polar bears are known for their need for privacy and new-borns are extremely delicate, so the maternity den was closed to visitors.

The polar bear cub explores its enclosure at the wildlife park. Credit:AP

The survival of the cub could not be fully confirmed until this month, when bears emerge after winter.

But now the tiny polar bear is moving around "confidently," the zoo says, and will get star treatment in a documentary set to air on Channel 4 on Sunday.