The week in wildlife

Two Matschie's tree kangaroos (Dendrolagus matschiei), which are an endangered species, peer from a perch in the newly created YUS Conservation Area of Papua New Guinea Photograph: HO/guardian.co.uk

A four-week-old meerkat (not yet named) in its enclosure at Battersea Park children's zoo, London Photograph: Katie Collins/PA

Budding trees sit covered in snow following a snowstorm in Charlotte, North Carolina, US Photograph: Streeter Lecka/Getty Images

A rare albino dolphin, which has been spotted at Calcasieu Lake in Louisiana, US Photograph: Captain Erik Rue /guardian.co.uk

As the Indian subcontinent moves into spring, a baby caterpillar hangs from a banyan tree in Kolkata Photograph: Deshakalyan Chowdhury/AFP/Getty Images

An environmental policeman holds an Amazonian manatee calf – a protected species – rescued from an animal trafficker in Silves, Brazil Photograph: Stringer/brazil/Reuters

A Linne's two-toed sloth and a Malayan flying fox climb on the same branch in the fragile forest of Singapore zoo Photograph: How Hwee Young/EPA

A duck swims through the oily waters of the Moskva river in central Moscow Photograph: DMITRY KOSTYUKOV/AFP/Getty Images

Tree fellers at the National Trust's Barrington Court, Somerset, remove horse chestnuts stricken with bleeding canker, which is spreading through south-west England Photograph: Ben Birchall/PA

A long-tailed macaque – an endangered species – in a wildlife rescue centre in Quezon City, Philippines Photograph: Alanah M. Torralba/EPA

A young red-necked wallaby (Macropus rufogriseus) peers out of his mother's pouch at Duisburg zoo, western Germany Photograph: Philipp Guelland/AFP/Getty Images

The Anolis nitens tandai, a lizard that lives on the floors of the Amazonian rainforest, is thought to be in serious danger because of climate change Photograph: Laurie Vitt/guardian.co.uk

Six members of the antelope family. Clockwise from top left: addax, hirola, scimitar-horned oryx, springbok, saiga, and dama gazelle. More than 25% of the world's 91 antelope species are threatened with extinction Photograph: IFCW/AFP/Getty Images

Infra-red footage of the elusive Javan rhino, the most endangered mammal in the world - less than 60 believed to be alive. The rhinos were filmed at Ujung Kulon National Park in Java, Indonesia Photograph: AFP/AFP/Getty Images

The UK's first hotel for frogs is built in Redhall walled garden in Edinburgh, Scotland Photograph: Andrew Milligan/PA

Nearly 200 pilot whales and several dolphins beached themselves on King Island off southern Australia this week. About 50 of the animals were still alive Photograph: John Nievaart/AFP/Getty Images

Monarch butterflies gather on a tree branch at the Monarch Butterfly Biosphere Reserve near Chincua, Mexico Photograph: Marco Ugarte/AP

Jumilah, a Sumatran tiger, during a Roar and Snore at Taronga zoo, Sydney. The event allows visitors to stay overnight and see the animals in late evening and early morning walks, and go on behind-the-scenes tours Photograph: Jenny Evans/EPA