The week in wildlife

A Nymphaea thermarum waterlily, the smallest waterlily species in the world , with pads as small as 1cm in diameter, has been saved from extinction by Kew gardens Photograph: Andrew McRobb/Royal Botanic Gradens Photograph: Andrew McRobb/guardian.co.uk A grey egret feeds her newborn chicks in Guwahati. Scores of egrets build their nests among trees in the populated Panbazar area, a major business centre of Guwahati, at this time of the year. But the city's urban expansion threatens to reduce the number of nesting egrets as trees are cut down to make way for buildings Photograph: Biju Boro/AFP/Getty Images Photograph: Biju Boro/guardian.co.uk Hummingbirds are known for their ability to hover in mid-air by rapidly flapping their wings, 15 to 80 times a second, depending on the size of the bird Photograph: Luis Acosta/AFP/Getty Images Photograph: Luis Acosta/guardian.co.uk A leopard at the Born Free Foundation in the Shamwari game reserve, South Africa. The animal hospital was built to enable vets to treat and accommodate diseased and injured wild animals Photograph: Gianluigi Guercia/AFP/Getty Images Photograph: Gianluigi Guercia/guardian.co.uk A pair of purple herons are nesting for the first time in the UK, conservationists say. The striking birds breed in southern Europe and visit Britain in small numbers each year Photograph: Paul Oomen/Getty Images Photograph: Paul Oomen/guardian.co.uk A dragonfly tries to clean itself as it is stuck to marsh grass covered in oil from the Deepwater Horizon oil spill Photograph: Gerald Herbert/AP Photograph: Gerald Herbert/guardian.co.uk Tadpoles seek refuge around a cluster of tree seeds in an ephemeral pond in Cedar Rapids, Iowa. The ponds built in the Cedar River flood plain are meant as new homes for the area's sagging frog population. Frogs have suffered from the dramatic loss of ephemeral ponds. The term refers to ponds that fill up in early spring with snow melt and rain and then disappear in the heat and dryer months of summer Photograph: Jim Slosiarek/AP Photograph: Jim Slosiarek/guardian.co.uk Water beads form on grass growing in a bed of moss near a stream about five miles from Mount St Helens in Washington state. The volcano erupted violently 30 years ago, and scientists are closely studying the regrowth of plants and trees in the area that was devastated by the blast Photograph: Ted S. Warren/AP Photograph: Ted S. Warren/guardian.co.uk The world's smallest known wallaby. Scientists exploring a remote Indonesian forest say they have uncovered a collection of new species , including the wallaby, a Pinocchio-nosed frog and a yellow-eyed gecko Photograph: Tim Laman/National Geographic/Reuters Photograph: Tim Laman/National Geographic/guardian.co.uk Ratu, a 8 year-old female Sumatran rhinoceros at the Sumatran rhino sanctuary in the Way Kambas national park, Lampung province. The species is threatened by poaching and habitat loss, an Indonesian rhino foundation said Photograph: Supri/Reuters Photograph: Supri/guardian.co.uk Liolaemus pictus , a viviparous Chilean lizard typical of temperate forests. Global warming may kill off a fifth of global lizard species by 2080 , says a study this week Photograph: P. Victoriano Photograph: guardian.co.uk On a slope above a beautiful small mountain lake called Gasinmdikana, gorilla mother Munezero with her newborn cradled in her arms , and with brother Ubutwali in right hand picture. A year-long study of the great apes at Bai Hokou in the Central African Republic has found that gorillas are being dangerously stressed by tourists whose attentions are disrupting the animals' feeding routines and making them aggressive Photograph: Gorilladoctors.org Photograph: guardian.co.uk Beetles on a branch during a bioblitz audit of Juliette Jowitt's garden with botanists from the Natural History Museum Photograph: Linda Nylind/Guardian Photograph: Linda Nylind/guardian.co.uk A young Perch (Perca fluviatilis) camouflaged amongst reeds in Lake Como, Italy. How well did you do in environment guardian's quiz this week? Photograph: Angelo Giampiccolo//Rex Features Photograph: Angelo Giampiccolo//guardian.co.uk A bee sits on a Damascene rose during the picking season at Mrah village, north of Damascus 38 miles. The Firdos Project, a part of the Syrian Trust for Development, supports farmers in order to revive the cultivation of the Damascene rose which is useful for perfume industries, medicine and natural drinks Photograph: Khaled Al-hariri/Reuters Photograph: Khaled Al-hariri/guardian.co.uk Boreal Forest, Gros Morne national park, Newfoundland, eastern Canada. Environmental action groups called a halt to decades of protests and came to a truce with logging companies in a deal that will preserve an enormous swath of forest in Canada's northern wilderness Photograph: Mike Grandmaison/Corbis Photograph: Mike Grandmaison/guardian.co.uk Male red-eyed treefrogs clutch one another during an intense wrestling match, hanging on to a leaf by only their hind legs Photograph: Michael S. Caldwell Photograph: guardian.co.uk A new species of bird for science has been discovered and named after a leading conservation family. The new species of antpitta, native to Colombia, South America, is named Fenwick’s antpitta, after the American Bird Conservancy president George Fenwick Photograph: Fundacion ProAves Photograph: guardian.co.uk