Spectators in Moscow were treated to the site of humorously designed makeshift aircraft plunging into the Muskova River during the Red Bull Flugtag Moscow 2011 competition. 38 teams took part at the Flugtag – which means “flying day” – a competition in which teams in fancy dress attempt to pilot human-powered, home-made flying machines off a six-meter-high platform into water.

Photo: A makeshift aircraft plummets into the Moskva River during the Red Bull Flugtag Moscow 2011 competition. (Photo by Sergei Karpukhin/Reuters)

A naked Hindu holy man arrives to bath in the Godavari River during Kumbh Mela, or Pitcher Festival, at Trimbakeshwar in Nasik, India, Saturday, August 29, 2015. Hindus believe taking a dip in the waters of a holy river during the festival, will cleanse them of their sins. According to Hindu mythology, the Kumbh Mela celebrates the victory of gods over demons in a furious battle over a nectar that would give them immortality. (Photo by Rajanish Kakade/AP Photo)

Malian workers haul out a boat they use to carry sand collected from the river bed during a routine maintenance on October 7, 2018, in the port of Bamako. Increasing construction in the Malian capital has boosted the demand for bricks made out of high-quality Niger River sand. (Photo by Michele Cattani/AFP Photo)

One month-old endangered Bornean Orang Utan sleeps on his mother named Miri on Wednesday, March 6, 2013, in Singapore. The Singapore Zoo is renowned for its flagship animal, the Orang Utan, and exhibits both the endangered Bornean and critically endangered Sumatran sub-species in a social setting. It is also known for its efforts in promoting and educating the public about the importance of wildlife conservation through its educational programs and breeding of these endangered species. (Photo by Wong Maye-E/AP Photo)

Photo taken on September 19, 2015 shows a baby Brazilian opossum at the “Parque Estoril” zoo in Sao Bernardo do Campo of Sao Paulo, Brazil. According to local press, the “Parque Estoril” zoo houses currently 23 orphan cubs of wild animals rescued in the south region of Sao Paulo, victims of illegal wildlife trade or problems caused by urban growth. According to the zoo, all the animals arrived in the last three months, and many of them, not being able to be reintroduced to their natural habitat, will be used as examples in environmental education classes. (Photo by Rahel Patrasso/Xinhua via ZUMA Wire)

“Are you here for the Winery Tour?” This is a Western Grey Kangaroo caught lounging in the wineries of the Adelaide Hills in South Australia. This past Autumn has been a spectacular time for wildlife viewing and I got lucky to spot this guy while mountain biking in the hills. Such a funny stance it just begs the question... Have you been drinking? ...and or... Are you here for the Winery Tour? Such a spontaneous moment I figured it would be perfect for an entry. I hope you like it! Cheers. Photo location: Adelaide Hills, South Australia, Australia. (Photo and caption by Greg Snell/National Geographic Photo Contest)

“Wong Maye-E joined AP as a staff photographer in 2003. Based in Singapore, Maye-E's work is centered around Sports reportage, entertainment, politics, and regional news stories. Maye-E has covered headlining events such as the 2014 World Cup, Thailand political protests, and the devastation of the Philippines Typhoon”. – Associated Press. Photo: A baby black howler monkey (Alouatta caraya) clings onto its mother's back on Thursday January 29, 2009 in Singapore where it's national zoo is actively involved in the conservation and education of wildlife reserves. (Photo by Wong Maye-E/AP Photo)

Natural world and wildlife shortlist. Lop Buri in Thailand is home to hundreds of macaques, which local residents consider to be disciples of the Hindu god Hanuman. While some people love them, others fear or even hate them. Despite the inconvenience they often cause, the macaques are generally respected and considered sacred. (Photo by Joan de la Malla/Sony World Photography Awards)