Ross Hoddinott / RF- Robin (Erithacus rubecula) portrait in snow. Near Bradworthy, Devon, UK. January. (This image may be licensed either as rights managed or royalty free.)

Ross Hoddinott / RF- Sunset on Kimmeridge Bay, Isle of Purbeck, Jurassic Coast World Heritage Site, Dorset, England, UK. November 2008. (This image may be licensed either as rights managed or royalty free.)

Nick Garbutt / RF - Herd of American Bison (Bison bison) around geo-thermal features. Firehole River Valley. Yellowstone National Park, Wyoming, USA. January 2008. (This image may be licensed either as rights manage...

Nick Garbutt / RF - Rocky Mountain bighorn sheep (Ovis canadensis canadensis) searching for grazing beneath deep snow. Lamar Valley, Yellowstone National Park, Wyoming, USA. January. (This image may be licensed eith...

Nick Garbutt / RF - Moon beam created by reflections from ice crystals in air, at full moon over Grand Canyon, Yelllowstone National Park, Wyoming, USA. January 2016. (This image may be licensed either as rights ma...

Nick Garbutt / RF - Sun beam created by reflections from ice crystals in air at sun rise over Grand Canyon, Yelllowstone National Park, Wyoming, USA. January 2016. (This image may be licensed either as rights manage...

Nick Garbutt / RF - North American bobcat (Lynx rufus). Madison River Valley, Yellowstone National Park, Wyoming, USA. January. (This image may be licensed either as rights managed or royalty free.)

Lynn M Stone / RF - Portrait of domestic Brittany dog on frosty grass at dawn. Canterbury, Connecticut, USA. Late November. (This image may be licensed either as rights managed or royalty free.)

Lynn M Stone / RF - Domestic male Great pyrenees dog in snow. Littleton, Massachusetts, USA. February. (This image may be licensed either as rights managed or royalty free.)

Lynn M Stone / RF - Head portrait of domestic male Great pyrenees dog in snow. Littleton, Massachusetts, USA. February. (This image may be licensed either as rights managed or royalty free.)

Lynn M Stone / RF - Domestic Yellow labrador retriever in snow. Clinton, Connecticut, USA. January. (This image may be licensed either as rights managed or royalty free.)

Carol Walker / RF - Grey Andalusian mare running in snow, Berthoud, Colorado, USA. January. (This image may be licensed either as rights managed or royalty free.)