The week in wildlife

An Adelie penguin in Cape Burks, western Antarctica. Adelie penguins ( Pygoscelis adeliae ) are found in the Southern Ocean round Antarctica, and breed further south than any other species of penguin Photograph: Yonhapnews Agency/EPA Photograph: Yonhapnews Agency/guardian.co.uk Norway: A pair of stranded deer on a frozen lake. Ivar Skregelid and his son Eivind Skregelid braved the ice to edge their way across the 160m-deep Sirdal Lake to rescue the deer Photograph: Tor Sindre Tjomlid/Rex Features Photograph: Tor Sindre Tjomlid/guardian.co.uk Minsk, Russia: A swan stretches its wings on a frozen lake Photograph: Viktor Drachev/AFP/Getty Photograph: Viktor Drachev/guardian.co.uk The British Indian Ocean territory of the Chagos islands is the UK's greatest area of marine biodiversity, home to at least 220 coral species and more than 1,000 species of fish. This week the 10,000th person joined a campaign to create the Earth's biggest marine protected area in the Chagos archipelago Photograph: Anne and Charles Sheppard/Chagos Conservation Trust Photograph: Anne and Charles Sheppard/guardian.co.uk Istanbul, Turkey: A squirrel in Yildiz park Photograph: Ibrahim Usta/AP Photograph: Ibrahim Usta/guardian.co.uk A zebra finch. This week, scientists recreated the colourful plumage of some of the earliest dinosaurs to grow feathers. They now believe that feathers evolved primarily for ornamental reasons and only later became adapted for insulation and flight Photograph: AFP/Getty Images Photograph: guardian.co.uk The World Bank has warned a 13-nation tiger summit that privately run tiger farms are inhumane and fuel demand for the endangered big cat's bones and skin Photograph: Aditya Singh/AFP Photograph: Aditya Singh/guardian.co.uk Santiago, Chile: A young Darwin's frog ( Rhinoderma Darwinii ), climbs on on dry leaves at a breeding centre in Concepcion University. The first frog of this species born in captivity was shown at the university this week. Scientists hope the breakthrough will be the key to repopulating the nearly extinct species Photograph: Reuters Photograph: guardian.co.uk Guerrero Negro, Mexico: A pair of ospreys nest on the top of a pole Photograph: Alexandre Meneghini/AP Photograph: Alexandre Meneghini/guardian.co.uk UK: Border Agency officers seized over a tonne of live rock coral at Manchester airport. The animals, which are protected under the Convention on International Trade In Endangered Species (Cites), were discovered in air freight which originated in Indonesia Photograph: Manchester Evening News Syndication Photograph: guardian.co.uk Ahmedabad, India: A wading bird in the polluted waters of the Sabarmati river Photograph: Ajit Solanki/AP Photograph: Ajit Solanki/guardian.co.uk A humpback whale breaching in waters off Hook Head, Co Wexford, Ireland Photograph: Padraig Whooley/PA Photograph: Padraig Whooley/guardian.co.uk