Mike Wilkes / Redwing (Turdus iliacus) puffed up against the cold, Warwickshire, England, UK, December.
Mike Wilkes / Blackbird (Turdus merula) female puffed up against the cold in the snow, Warwickshire, England, UK, December.
Roger Powell / Great spotted cuckoo (Clamator glandarius) perched on a post, with ruffled feathers, Castro Verde, Alentejo, Portugal.
Philippe Clement / Great tit (Parus major) with feathers puffed up against cold, perched on branch during snow shower in winter, Belgium, January.
Lynn M Stone / Moluccan Cockatoo (Cacatua moluccensis) with feathers puffed up, captive, endemic to the south Molucca Islands in eastern Indonesia.
Ben Cranke / Japanese Macaque (Macaca fuscatata) juvenile with fur puffed up hooting in alarm, Jigokudani, Nagano Prefecture, Honshu, Japan
Diane McAllister / Japanese Macaque (Macaca fuscata) juvenile with puffed up fur in the snow, Jigokudani, Japan, January
Danny Green / Adult male Sparrowhawk (Accipiter nisus) stretching its wings, Dumfries, Scotland, UK, February.
David Kjaer / Great Bustard (Otis tarda) female puffed up against the cold, in snow on Salisbury Plain, part of a reintroduction project with birds imported under DEFRA licence from Russia. Salisbury Plain, Wiltshi...
Juan Carlos Munoz / Lesser flamingo (Phoeniconaias minor) with feathers puffed up, Lake Bogoria, Rift valley, Kenya, Africa
Fabrice Cahez / Eurasian Tree Sparrow (Passer montanus) with puffed up feathers at rest under the snow, Vosges, France, January