The week in wildlife - in pictures

A bighorn sheep at the Banff national park in Canadian Rockies Photograph: Huang Xiaonan/Corbis

A butterfly on a lavender flower. Sir David Attenborough urged people to take part in a nationwide count of butterflies to help find out if the hot, dry spring has hit the insects Photograph: Andrea Comas/Reuters

The Philippines has warned against using geckos to treat Aids and impotence, saying the folkloric practice in parts of Asia may put patients at risk. Environmental officials have also expressed alarm about the growing trade in the wall-climbing lizards in the Philippines Photograph: Bullit Marquez/AP

A lion holding its cub in its mouth in the Masai Mara, which has the only growing population of lions in East Africa Photograph: Paul Goldstein/Kicheche/Exodus Travels

A 13-year-old male western chimpanzee disciplining playful three-year-old infant male in Mont Nimba, Guinea Photograph: Anup Shah/Fiona Rogers / Rex Fea/Rex Features

A spotted deer inside a deer park in the premises of Pashupatinath Temple in Kathmandu Photograph: NAVESH CHITRAKAR/Reuters

A carpenter bee collects pollen from a flower Photograph: Franck Robichon/EPA

Ya Kwanza the 27-year-old silverback gorilla managed a few vanity close-ups of himself - before throwing the camera back at his keeper Durrell Wildlife Conservation Trust, based in Jersey in the Channel Islands, decided that their most photographed primate should turn the tables and become cameraman for the day Photograph: Durrell Wildlife Conservation Trust

An adult female Sambas stream toad, or Bornean rainbow toad as it is also called. Conservationists have taken the first photographs of one of the world's most elusive amphibians, after it was found for the first time since the 1920s Photograph: Indraneil Das/Conservation Inter/Conservation International

An alpine plant on the south slope of the Himalayas, south-west China's Tibet Autonomous Region Photograph: Purbu Zhaxi/Corbis

Herdsmen line up to spray a special herbicide to diminish the poisonous grassland flowers called Stellera chamaejasma L on a pasture in the Gonghe county, in north-west China's Qinghai province. The plant are said to deprive nearby plants of water and grow rampantly, destroying the grassland unless measures are taken against it Photograph: Zhao ZP/EPA

A whale shark swims in the Caribbean Sea in Isla Mujeres. The Whale Shark Annual Festival has been taking place in Isla Mujeres since 2008 to promote eco-tourism and the conservation of this species considered vulnerable under the IUCN red list of threatened species Photograph: Stringer/Reuters

An Alaskan brown bear nods off in the river after catching some salmon Photograph: Rick Sheremeta/Rex Features

Critically endangered Amur leopards on video in Russia’s far east, caught in ‘video trap’ footage by the WWF Photograph: WWF/ISUNR

A white kiwi. Hundreds of spectators awaited a glimpse of the rare white kiwi at New Zealand's Pukaha sanctuary. The bird is held sacred by the country's indigenous Maori people Photograph: Mike Heydon/AFP/Getty Images

Pelicans fly to Mullet Island, one of the four Salton Buttes, small volcanoes on the southern San Andreas Fault, after sunset in California. Mullet Island, the only place for many thousands of island nesting birds to breed at the Salton Sea, will become vulnerable to attacks by predators such as raccoons and coyotes if the water level drops just a couple more feet Photograph: David McNew/Getty Images

Distinctive rings around trees left by an oil spill are seen along the Yellowstone river, seven miles downstream from the site of a ruptured pipeline in Yellowstone County Photograph: STR/Reuters

A pair of sarus cranes feed themselves in an agricultural field on the outskirts of Allahabad, India Photograph: Rajesh Kumar Singh/AP

One of 17 spoon-billed sandpiper chicks that have hatched in a captive breeding scheme to bring the bird back from the brink of extinction. The team of experts led by staff at the WWT and Birds Russia is attempting to save the critically endangered sandpiper, one of the world's rarest birds, whose numbers had fallen to an estimated 120-200 pairs in the wild by 2009 Photograph: MJ McGill/WWT