The week in wildlife - in pictures

An ibex silhouetted during sunrise after the Perseid meteor shower in the night sky over El Torcal nature park reserve in the southern Spanish town of Antequera. The Perseid meteor shower is sparked every August when the Earth passes through a stream of space debris left by comet Swift-Tuttle Photograph: Jon Nazca/Reuters

Swallows gather on street power lines early in the morning in the village of Ezerec, Bulgaria Photograph: Vassil Donev/EPA

A red squirrel peers down from the branches on Brownsea Island, Dorset Photograph: Dave Stevenson/Rex Features

The butterfly Heliconius numata (top) and one of the species it mimics, Melinaea mneme (bottom) as scientists have discovered a 'supergene' that helps butterflies copy their unpalatable neighbours to avoid being eaten by birds Photograph: Mathieu Chouteau/PA

Southern pig-tailed macaque (Macaca nemestrina) caught in a photo trap Photograph: Wildlife Conservation Society/TEAM network/Conservation International

The young red river hog (Potamochoerus porcus) Thomu walks next to his mother Dagamba at the Berlin zoo Photograph: TOBIAS KLEINSCHMIDT/EPA

The return of otters to the UK shows English rivers are the healthiest for 20 years, says the Environment Agency Photograph: Mike Powles/Getty Images

A small damselfly on a twig in New Braunfels, Texas Photograph: Eric Gay/AP

A new species of eel found in the gloom of an undersea cave which is a 'living fossil' astonishingly similar to the first eels that swam 200m years ago, biologists reported. The strange find was made last year in a 35-metre- (113-feet) deep fringing-reef cave off an island in the Western Pacific state of Palau Photograph: Jiro Sakaue/AFP/Getty Images

Sri Lankan wild elephants play at a wildlife sanctuary in Minneriya. Sri Lanka began surveying its wild elephant population living in national parks as part of a conservation drive to protect the dwindling animals. The island's elephant population has dwindled to 4,000 from a high of 12,000 recorded in 1900s, according to the Department of Wildlife Conservation Photograph: Ishara S.kodikara/AFP/Getty Images

A dog takes a closer look at a beached southern right whale on Danger Beach in Cape Town, South Africa. The juvenile whale beached itself early in the morning but after a few hours it was declared dead by Society for the Prevention of Cruelty to Animals (SPCA) vets. It is not known what killed the whale. Beaching of whales is a common occurence among sick whales. After samples were taken from the whale it was towed to a nearby harbour to be lifted from the water Photograph: Nic Bothma/EPA

Experts at Kew's Millennium Seed Bank are turning their hand to propagating an array of native flowers to help restore vanishing habitat such as meadows. The UK Native Seed Hub aims to grow plants which have proved difficult to cultivate in restoration programmes, to boost efforts by seed companies and conservation groups to create diverse habitats full of flowers Photograph: Andrew McRobb/RBG Kew

A spider spins a web early in the morning in a garden in Kathmandu, Nepal Photograph: Narendra Shrestha/EPA

A loica (long-tailed Meadowlark) stands in a snow-covered field in Argentina's Patagonian resort town of San Martin de Los Andes. Snow storms and blizzards disrupted transport and power shortages in the area while a polar front is expected to drag the temperatures down for the next few days, the National Meteorological Service (SMN) predicted Photograph: STR/Reuters

Walruses on an ice floe in the Chukchi sea in the Arctic. Fast-melting Arctic Sea ice appears to be pushing walruses to haul themselves out on to land, and many are moving around the area where oil leases have been sold, the US Geological Survey reports Photograph: HO/Reuters

An American pikain in California. Animals across the world are fleeing global warming by moving regions twice as fast as they were less a decade ago, a new study says Photograph: Scott Loarie/Stanford University /AP

A stork perched on the roof of a house in Sieversdorf, northern Germany silhouetted against a full moon. In just a matter of weeks storks will be planning their annual winter migration to southern destinations Photograph: Patrick Pleul/EPA