The week in wildlife

The moon lights up snow on Wangum Lake near Norfolk in the US state of Connecticut Photograph: Stan Honda/AFP/Getty Images Photograph: Stan Honda/guardian.co.uk Lambs in a snowy field in Catterick, north Yorkshire, try to keep warm. Snow is once again forecast for parts of the UK Photograph: John Giles/PA Photograph: John Giles/guardian.co.uk A tigress wearing a radio collar wades through a river after being released by wildlife workers in Storekhali forest, 130km south of Kolkata, India. The animal had been caught close to human habitation. WWF India has enlisted the support of sports stars and celebrities to raise awareness of the threat posed by human encroachment on tiger habitat, citing government estimates that there are just over 1,400 tigers left in the wild Photograph: Deshakalyan Chowdhury/AFP/Getty Images Photograph: Deshakalyan Chowdhury/guardian.co.uk Birds search for honey in Simolu flowers near Guwahati. The Simolu trees are in full bloom, a traditional herald of spring in northeast India Photograph: STR/EPA Photograph: STR/guardian.co.uk These two lovebirds have produced the first Sumatran rhino pregnancy in south-east Asia for the global captive breeding program. Ratu (left) and her mate Andalas, both eight years old, live in a breeding sanctuary at Way Kambas national park in Lampung, South Sumatra, Indonesia Photograph: Yabi Handout/EPA Photograph: Yabi Handout/guardian.co.uk Birds take to the air above the Mai Po nature reserve between Hong Kong and the mainland Chinese town of Shenzhen. Some 60,000 birds fly from as far as Arctic Siberia and central Asia to winter in marshes squeezed between the two urban giants of Hong Kong and Shenzhen, or to rest and fatten up before continuing down to Australia and New Zealand Photograph: Ed Jones/AFP/Getty Images Photograph: Ed Jones/guardian.co.uk A veterinarian examines a bird near Jammu, India, as part of a three-day long migratory bird surveillance programme to detect the H5N1 bird flu virus Photograph: Channi Anand/AP Photograph: Channi Anand/guardian.co.uk A dead snail lies on a cracking reservoir in Yunnan. Severe drought has hit China hard, its government says, damaging about 3.56m hectares of crops and causing water shortages Photograph: Stringer Shanghai/Reuters Photograph: Stringer Shanghai/guardian.co.uk A male Sundaland clouded leopard – only recently caught on camera for the first time – stalks the Dermakot Forest Reserve in Borneo. It has only been listed as a distinct species since 2008 Photograph: HO/Reuters Photograph: HO/guardian.co.uk Populations of monkeys, such as this Udzungwa red colobus, in threatened forests are far more sensitive to damage to their habitat than previously thought, according to new research Photograph: Andrew Marshal/University of York Photograph: Andrew Marshal/guardian.co.uk Forest officials examine a rhinoceros killed by poachers inside Kaziranga National Park in Assam, India. At least 18 rhinos were killed in 2008 and 14 in 2009. Six have been killed this year so far – five in Kaziranga and another at Orang National Park in northern Assam. Poachers kill the animals for their horn, which in several cultures is believed to have medicinal or magical properties Photograph: STR/AFP/Getty Images Photograph: STR/guardian.co.uk The North Americans may be terrified of them , but in China the so-called 'Terminator' fish, the Asian carp , is in great demand. Here, a Chinese official releases the fish into Taihu Lake in Suzhou, which has been severely polluted by sewage, as well as industrial and agricultural waste, triggering a virtual plague of blue-green algae – a tasty treat for the voracious carp. Authorities say they will release 20m of the algae-eating fish into one of China's most scenic but contaminated lakes as part of a cleanup programme Photograph: STR/AFP/Getty Images Photograph: STR/guardian.co.uk A fox enjoys the winter sunshine in a garden in Kingston upon Thames Photograph: Steve Parsons/PA Photograph: Steve Parsons/guardian.co.uk Catkins lead the charge of the long-awaited changing of the seasons. Got some spring snapshots? Send them our way Photograph: Graham Turner/Guardian Photograph: Graham Turner/guardian.co.uk