Winner. “This was taken in the South Ari Atolls, Maldives, as the south-west monsoon season was setting in. It features my partner – and dive buddy – Emma after surfacing at the end of the last dive of the day to find 1.5 metre swells and dark monsoon clouds. MICK RYAN, JUDGE: This beautiful portrait of a diver in an ocean swell below a menacing sky stands out this month for its emotional and elemental beauty. It is a reminder that while we may play among nature we are always dwarfed by its power and must be constantly on our guard”. (Photo by Simon Dunn/The Guardian)

Neil Zeller's snaps were taken across Canada, where he photographs the northern lights dancing across a dark night sky. In one stunning shot, Zeller, 42, even manages to capture a flash of lightning beneath a storm cell while an aurora gives off a magnificent green glow. The photographer, from Calgary, Alberta, describes himself as a night person, and became interested in night photography about 10 years ago. (Photo by Neil Zeller/Caters News)

People and Nature category winner: Why did the sloth cross the road? by Andrew Whitworth (Osa Conservation and University of Glasgow), taken in Osa Peninsula, Costa Rica. “I was driving out from the Osa Peninsula, located on the southern Pacific coast of Costa Rica on a dark, stormy day. This female three-toed sloth (Bradypus variegatus) had luckily just about made it across the road, and the drivers of the Toyota on this occasion had spotted her in good time”. (Photo by Andrew Whitworth/2019 British Ecological Society Photography Competition)

“Senorita” – California-native fashion model Tiffany Keller heats up photographer Vladimir Marti’s lens for the April 2013 issue of Marie Claire Latin America. The dark-haired beauty poses in the city of San Miguel de Allende, Mexico, donning sultry styles from designer labels selected by fashion editor and stylist Gerard Angulo. (Photo by Vladimir Marti)

Gers, traditional Mongolian tents, are seen on a hill in an area known as a ger district in Ulan Bator June 26, 2013. Approximately 60 percent of the population of Ulan Bator live in settlements known as ger districts and in many cases residents have limited access to basic services such as water and sanitation. According to a 2010 National Population Center census, every year between thirty and forty thousand people migrate from the countryside to the capital Ulan Bator. Ger districts in the city have been expanding rapidly in recent years. Mongolia is the world's least densely populated country, with 2.8 million people spread across an area around three times the size of France. (Photo by Carlos Barria/Reuters)

Jacob's Well is a perennial karstic spring in the Texas Hill Country flowing from the bed of Cypress Creek, located northwest of Wimberley, Texas. The twelve foot (four meter) diameter mouth of the spring serves as a popular swimming spot for the local land owners whose properties adjoin Cypress Creek. From the opening in the creek bed, Jacob's Well cave descends vertically for about thirty feet (ten meters), then continues downward at an angle through a series of silted chambers separated by narrow restrictions, finally reaching a depth of one hundred and twenty feet (forty meters). Until the modern era, the Trinity Aquifer-fed natural artesian spring gushed water from the mouth of the cave, with a measured flow in 1924 of one hundred and seventy gallons per second (six hundred and forty liters per second) discharging six feet (two meters) into the air. The spring is the greatest source of water recharging the Edwards Aquifer.

Pontoons, which were previously used as a floating jetty, are seen on the cracked ground of the Atibainha dam, part of the Cantareira reservoir, during a drought in Nazare Paulista, Sao Paulo state February 12, 2015. Brazil's worst drought in 80 years has left the Cantareira system, that provides greater Sao Paulo with most of its water, with the lowest water level on record. Brazil's economy is already expected to post zero growth this year. Worse yet, since Brazil depends on hydroelectric dams for about three quarters of its electricity, power shortages are also possible due to the drought, federal officials have said. (Photo by Paulo Whitaker/Reuters)