Opossums on their mothers back at a game reserve in Central Minnesota, USA, on September 2, 2013. (Photo by Caters News Agency)

An orphaned giraffe nuzzling a wildlife keeper at Sarara camp in Kenya, one of 70 pictures being sold by Prints for Nature (printsfornature.com) to raise money for work by the Conservation International charity. This giraffe was rehabilitated and returned to the wild, as a number of others have done before him. Right now, giraffe are undergoing what has been referred to as a silent extinction. Current estimates are that giraffe populations across Africa have dropped 40 percent in three decades, plummeting from approximately 155,000 in the late 1980s to under 100,000 today. (Photo by Ami Vitale/National Geographic)

Polar bear twins make their first public appearance with their mother “Freedom” at Ouwehands Zoo Rhenen, in Rhenen, The Netherlands, 19 February 2015. The twins, who were born in November 2014, have not been named because their gender has not yet been determined. (Photo by Bart Maat/EPA)

Local resident Rita holds a cat while her neighbour Raisa saws firewood next to their residential building heavily damaged by permanent Russian military strikes in the front line town of Avdiivka, amid Russia's attack on Ukraine, in Donetsk region, Ukraine on November 8, 2023. (Photo by Serhii Nuzhnenko/Radio Free Europe/Radio Liberty via Reuters)

The fourth annual BigPicture Natural World Photography Competition aims to celebrate the diversity of life on Earth, and encourages people to protect and conserve it. Here: “The Salmon Catchers”. Terrestrial Wildlife. To capture this view of a mother grizzly bear and her cub, photographer Peter Mather set up a camera trap on a log that he knew the bears tended to traverse while fishing for salmon, in the Yukon River watershed in Canada. (Photo by Peter Mather/BigPicture Natural World Photography Competition 2017)

This lemur looks like he is channelling the spirit of Buddha – as he sits meditating. Sitting with his legs crossed, the lemur clasps his thumb and fore finger together with outstretched arms – just like the spiritual teacher. And amateur snapper Sebastien Degardin, 32, was on hand to capture the bizarre moment the animal searched for enlightenment on film. Sebastien, who moved from his native Belgium to Finchley, North London, said: “I was gobsmacked when I saw this lemur meditating”. (Photo by Sebastien Degardin/Caters News)

“The Challenge!” Young boy relishes in a game of tug of war before school. Photo location: Lake Titicaca, Peru. (Photo and caption by Paul Heyman/National Geographic Photo Contest)

This month’s selection of travel imagery mixes quiet moments and superlative views. The overall 2018 prize is a West Greenland trip with Wild Photography Holidays. Here: “This was taken on a safari in Kruger national park, South Africa. The scene was like something straight out of a storybook: a wild baboon, impala and elephant crossing the road together, all lined up neatly in a row”. (Photo by Will Clarke/The Guardian)