Ben Hall / Whooper swan (Cygnus cygnus) in snowfall. Martin Mere Wetlands Trust, Lancashire,UK, January. 'Animal Portraits' category, British Wildlife Photographer Awards (BWPA) competition 2012.

Andrew Parkinson / Whooper swan (Cygnus cygnus) adult aggressively chasing another, UK visitor between November and March. Lancashire, UK, October.

Eric Baccega / Polar bear (Ursus maritimus) female and her two cubs on large iceberg off Baffin Island. Nunavut, Canada, August 2010

Eric Baccega / Polar bear (Ursus maritimus) female and her two cubs on an iceberg, off Baffin Island. Nunavut, Canada, August 2010

Andy Rouse / Whooper swans (Cygnus cygnus) at sunset, Martin Mere WWT, Lancashire, UK

Alan Williams / Common teal (Anas crecca) male displaying, Martin Mere WWT, Lancashire, UK, February

Alan Williams / Pintail (Anas acuta) male flapping wings after bathing, Martin Mere WWT reserve, Lancashire, UK, February

Mike Potts / Pintail ducks (Anas acuta), Four males courting one female, Martin Mere, Lancashire, UK February

Eric Baccega / Polar bear + cubs resting {Ursus maritimus} Churchill, Manitoba, Canada

Eric Baccega / Polar bear with two 3-month-old cubs {Ursus maritimus} Churchill, Manitoba, Canada

Eric Baccega / Polar bear with two 3m-old cubs {Ursus maritimus} Churchill, Manitoba, Canada

Eric Baccega / Polar bear resting with 3month-old cubs {Ursus maritimus} Churchill, Manitoba,