Women perform square dancing at a park square in Beijing, China, April 9, 2015. Chinese-style square dancing is running circles around other hobbies for the elderly, with millions taking to parks and plazas across China, swivelling their hips and rolling their arms – but it's not to everyone's liking. (Photo by Kim Kyung-Hoon/Reuters)

Californian photographer and conservationist Octavio Aburto had spent years photographing the school in Cabo Pulmo National Park, Mexico – and had been trying to capture this exact shot for three years. “Together with my friend David Castro, we were diving with a large group of Bigeye travellies at Cabo Pulmo National Park, Mexico. Thousands of fish forming a ball during the reproduction courtship. In the afternoon, these fish congregate to form a large spawning aggregation around the reefs of the National Park”. (Photo and caption by Octavio Aburto)

A reveller takes part with her dogs in the annual halloween dog parade at Manhattan’s Tompkins Square Park in New York, U.S. October 22, 2016. (Photo by Eduardo Munoz/Reuters)

A man dressed as the Sesame Street character Big Bird sits on a bench waiting to take pictures with people walking through Central Park in New York U.S., November 14, 2016. (Photo by Shannon Stapleton/Reuters)

The Paddington Bear balloon floats down Central Park West during the 90th annual Macy's Thanksgiving Day Parade on November 24, 2016 in New York. (Photo by Kena Betancur/AFP Photo)

A performer in traditional costume waits for her turn to go on stage at Longtan park as the Chinese Lunar New Year, which welcomes the Year of the Rooster, is celebrated in Beijing, China January 29, 2017. (Photo by Damir Sagolj/Reuters)

A girl watches an acrobatic performance at the Longtan park as the Chinese Lunar New Year, which welcomes the Year of the Monkey, is celebrated in Beijing, China February 9, 2016. (Photo by Damir Sagolj/Reuters)

A dog dressed in a costume takes part in the Pet's Halloween Day parade at El Olivar Park in San Isidro, Lima, October 31, 2015. (Photo by Mariana Bazo/Reuters)