Marie Read / Loggerhead shrike (Lanius ludovicianus) on an ice-covered fence after an ice storm, Anahuac National Wildlife Refuge, Texas, USA. January.

Guy Edwardes / Buachaille Etive Mor in winter, Rannoch Moor, Highlands, Scotland, UK. January 2015.

Sven Zacek / Pink algae in fresh snow on the coast of the Baltic Sea, Lahemaa National Park, Northern Estonia. December 2012.

David Pattyn / Alpine ibex (Capra ibex) male in deep snow with icicles behind, Gran Paradiso National Park, Italy. December

Bryan and Cherry Alexander / Icicles hanging from the edge of a small blue iceberg as the summer thaw sets in, Antarctica

Olga Kamenskaya / Ice splash out formation with icicles, Lake Baikal, Siberia, Russia, March

Ben Cranke,Ben Cranke / Gentoo Penguin (Pygoscelis papua) group travelling out to sea, Cuverville Island, Antarctic Peninsula, Antarctica

Sandra Bartocha / Light reflected through icicles, Tollensesee, Germany, January

Chadden Hunter / Brinicles (brine icicles or ice stalactites) forming under the ice, growing towards the sea floor, Ross Sea, McMurdo Sound, Antarctica. Taken on location for 'Winter' episode of the BBC Frozen Planet...

Brent Stephenson / A large hole in an iceberg with icicles hanging. Yalour Islands, Antarctic Peninsula, Antarctica, December.

Chadden Hunter / Person standing infront of long icicles, outside volcanic ice cave, Mount Erebus, Antarctica. Taken on location for BBC Frozen Planet series, 2009

Bryan and Cherry Alexander / Icicles at entrance to cave in a small iceberg, Antarctica, 2009.