Week in wildlife

Budapest, Hungary: an animal keeper feeds moon jellyfish with a syringe containing brine shrimp. The body of the moon jellyfish, found in tropical waters, is 95% water. Keeping these animals is very difficult: their bodies are fragile and can be harmed even by bubbles of air. Because of this and the difficulties of reproducing oceanic conditions in the zoo, the moon jellyfish must be fed individually Photograph: Bela Szandelszky/AP

Svalbard, Norway: a young husky pup. It will soon be old enough to used as a sled dog Photograph: John McConnico/AP

Gloucestershire, UK: a female great bustard spotted feeding in a field near Oldbury power station. The great bustard is one of the largest flying birds in the world, and was regarded as extinct on the British Isles Photograph: Oldbury Power Station/PA

Wabash, Canada: four cats avoid the snow Photograph: Dave Chidley/The Canadian Press/AP

Lexington, US: a mare and her foal run through the falling snow on Shadwell farm Photograph: David Stephenson/Herald-Leader/AP

Leipzig, Germany: a Hungarian pointer yawns during the fitting of a fleece jumper at Germany's first custom tailor shop for dogs Photograph: Waltraud Grubitzsch/EPA

Liberia: the elusive and endangered pygmy hippopotamus, which has managed to survive two civil wars and habitat destruction. One of the most secretive large mammals, the pygmy hippo is rarely seen in the wild but was caught on camera in the country's national park Photograph: Sapo Zoological Society of London/PA

Ayutthaya, Thailand: elephants eat fruits during a feeding ceremony. Sixty-nine tamed elephants took part at the ceremony sponsored by local businessmen to celebrate national elephant day Photograph: Apichart Weerawong/AP

Cumbria, UK: a flock of oyster catchers fly over breaking waves between Allonby and Silloth Photograph: Owen Humphreys/PA

Sydney, Australia: a keeper holds a green tree frog in his hand. It is currently year of the frog. Australian zoos are to join a global programme to save endangered frogs Photograph: Anonek De Groot/AFP

Budapest, Hungary: Jorek, a one-year-old, 150kg polar bear cub, stands on his hind legs after a swim in his new home in Animal Park Photograph: Istvan Kiss/EPA

London, UK: Sir David Attenborough with a giant atlas moth. Attenborough is launching a pioneering project that will help to reverse a 76% decline in the UK's butterfly species Photograph: Andy Rain/EPA

A queen ant and a worker ant. Ants may be held up as models of social cooperation, but research this week suggests they can be as corrupt and selfish as human beings. The insects have always been thought to work together for the benefit of the colony rather than for individual gain. But scientists have discovered that some ants are able to cheat the system, ensuring their offspring become reproductive queens rather than sterile workers Photograph: D R Nash/PA

Sichuan, China: a baby panda at the Chengdu research base for giant panda breeding Photograph: Liu Jin/AFP