A couple takes a selfie as Hoa Binh hydroelectric power plant opens the flood gates after a heavy rainfall caused by Talas typhoon in Hoa Binh province, outside Hanoi, Vietnam July 20, 2017. (Photo by Reuters/Kham)

Indigenous Sahrawi girls play on an improvised see-saw at a refugee camp of Boudjdour in Tindouf, southern Algeria March 3, 2016. UN Secretary General Ban Ki-moon is scheduled to visit the Sahrawi refugees in south-west Algeria's Tindouf region. (Photo by Zohra Bensemra/Reuters)

A Monster Jam truck performs a back flip during the first-ever monster truck event in Beijing's iconic “Bird's Nest” National Stadium on Saturday, July 29, 2017. (Photo by Ng Han Guan/AP Photo)

Young girls perform in front of the monument to Soviet state founder Vladimir Lenin during the City Day celebrations in Yekaterinburg, Russia on August 19, 2017. (Photo by Maxim Shemetov/Reuters)

A flood affected boy on a makeshift banana raft collects biscuit packets distributed by a government official from a boat in Pokoria village, east of Gauhati, north eastern Assam state, India, Monday, August 14, 2017. Heavy monsoon rains have unleashed landslides and floods that killed dozens of people in recent days and displaced millions more across northern India, southern Nepal and Bangladesh. (Photo by Anupam Nath/AP Photo)

A man in “Red Army” garb hits the pavement during a simulated attack during a re-staging of part of the Long March in Jinggangshan September 14, 2017. The scene brings alive an extraordinary chapter in China's history that established the supremacy of Chairman Mao Zedong and the Communist Party. Deep in the mountains of Jinggangshan in the southeastern province of Jiangxi, a classroom of bank tellers participates in an ideological boot camp that plays into Chinese President Xi Jinping's drive to further consolidate his grip on power. (Photo by Thomas Peter/Reuters)

Behaviour: Mammals category. Giant Gathering by Tony Wu, USA. Dozens of sperm whales mingled noisily off Sri Lanka’s northeast coast, stacked as far down as Tony could see. This was a congregation of dozens of social units, like a gathering of the clans. Aggregations like this could be a critical part of the whales’ rich social lives but are rarely reported. Some two thirds of the population was wiped out before commercial whaling was banned in 1986. This kind of major gathering could be “a sign that populations are recovering”, says Tony. (Photo by Tony Wu/Wildlife Photographer of the Year 2017)

Andrew Parkinson, animal behaviour category winner: Crepuscular Contentment, Derbyshire. “In 15 years of working with badgers I’ve never seen a badger sit out in the open to have a scratch. I was sat concealed behind a tree and downwind so it was especially nice that the badger had his back to me, demonstrating just how inconspicuous and inconsequential my presence was”. (Photo by Andrew Parkinson/British Wildlife Photography Awards 2017)