The week in wildlife – in pictures

Two impala drink from a river as a crocodile approaches in South Luangwa national park in Zambia. The crocodile moved slowly on the surface of the water and then hid at the very edge of the river bank. It was spotted by an elephant, who unsuccessfully tried to shepherd the impala away from the riverside - even trying to stamp on the submerged crocodile Photograph: Rob Brookes/Barcroft Media

Eventually the crocodile attacked, but was thwarted by the impala's quick reactions. The dramatic images were captured by amateur photographer Rob Brookes Photograph: Rob Brookes/Barcroft Media

Birds are seen silhouetted at Qinghai Lake, north-west China Photograph: Wu Gang/Corbis

A stag and deer race across a snow-covered meadow in Neustadt am Rübenberge Photograph: Alexander Körner/Corbis

Virunga, in the Democratic Republic of the Congo, is Africa's oldest national park and a world heritage site. Its rainforests, volcanoes and rare wildlife attract tourists and its natural resources support more than 50,000 people. But the park is at risk of becoming Africa's newest oil field after London-based oil company Soco announced exploration plans. Virunga is home to one-quarter of the world’s critically endangered mountain gorillas, which have been a source of tourism revenue in peaceful times. A series of images taken by Brent Stirton is being used in WWF's Draw the Line campaign, which aims to protect the park from oil exploration Photograph: Brent Stirton/WWF

A Gentoo penguin tries to get its beak around a GoPro camera on Cuverville Island, Antarctica. Alok Jha, science correspondent at the Guardian, is currently en route to Antarctica with the Australasian Antarctic Expedition 2013 and live blogging his journey here Photograph: Alex Cowan/Barcroft Media

A grizzly bear mother and her cub near Pelican Creek, Yellowstone national park, Wyoming. US wildlife managers have recommended lifting endangered species protection for grizzly bears in the park, which - if approved - could open the way for them to be hunted again Photograph: Karen Bleier/AFP/Getty Images

A Hardwicke's or Indian spiny-tailed lizard at the Tal Chhapar sanctuary in Rajasthan, India Photograph: Arkaprava Ghosh/Barcroft India

An insect on a 'Mandela's gold' (Strelitzia Reginae) bird of paradise flower in the Kirstenbosch national botanical gardens in Cape Town. The yellow flowering variety was named after former South African president Nelson Mandela, who died last week Photograph: Stringer/Reuters

A guillemot dives underwater near the Farne Islands, northern England. The islands, which lie off the Northumberland coast, are home to a huge array of wildlife. Owned and protected by the the National Trust, they host some 23 species of seabird, as well as a substantial colony of grey seals Photograph: Nigel Roddis/Reuters

The comb jelly may represent 'the earliest branch of the animal tree' and not sponges as previously thought, scientists say Photograph: Stefan Siebert/Brown University/AP

A pair of spotted tiger beetles mating on the banks of Jayanti River in the Buxa national park in Alipurduar, India Photograph: Arkaprava Ghosh/Barcroft India

A blackbird eating apples from a garden tree. Sir David Attenborough has warned that cats are killing huge numbers of birds in British gardens Photograph: Roland Weihrauch/ Corbis

A large elephant group heading toward the Salamat River, Zakouma national park, Chad. Award-winning photographer Michael Nichols' book tells the story of elephants through pictures taken over 20 years in Africa - watch the audio slideshow here Photograph: Michael Nichols/Getty Images

Birds fly above the waves in Langeness, Germany. Hurricane-force Xaver struck northern Europe on Thursday night, killing six people and causing flooding, damage and transport disruption across Poland, Germany, the Netherlands and southern Sweden Photograph: Maja Hitij/Corbis