A woman rolls a marijuana cigarette during the first “Expo Cannabis” fair in Montevideo December 14, 2014. Expo Cannabis offers conferences about different topics such as the medicinal use of cannabis and cultivation techniques as well as displaying hemp goods, cannabis cultivation items and seeds. (Photo by Andres Stapff/Reuters)

Women balance on a “mikoshi” or portable shrine as people carry it into the sea during a festival to wish for calm waters in the ocean and good fortune in the new year in Oiso, Kanagawa prefecture, west of Tokyo, Japan, January 1, 2016. (Photo by Yuya Shino/Reuters)

A woman sells statues of the Ekeko, god of fortune, at the traditional “Alasitas” fair in La Paz January 24, 2015. During the fair, Bolivians buy miniature versions of goods like cars, money and houses they would like to own in real life during the year. (Photo by David Mercado/Reuters)

A woman dressed for la “La Diablada” festival walks down a road in Pillaro, Ecuador, Friday, January 6, 2017. Local legend holds that anyone who adopts a costume for the celebration and wears it at the event six years in a row will have good luck. (Photo by Dolores Ochoa/AP Photo)

Food is placed on the tomb of pet dog Xixi at Baifu pet cemetery ahead of the Qingming Festival on the outskirts of Beijing, China March 26, 2016. The Chinese characters on the gravestone read: “Mommy's only good son”. (Photo by Jason Lee/Reuters)

People smear black ash with hands onto each other to wish for good luck and fortune during a traditional festival of the Yi ethnic minority in Qiubei County, Yunnan province, China July 18, 2017. (Photo by Ren Dong/Reuters/CNS)

People decorate a street with candles inside oranges during the Epitaph ceremony during Good Friday's “Apokathelosis”, the Descent of Christ's dead body from the Cross, which forms a key part of Orthodox Easter, in the southern city of Leonidio, at the Peloponnese peninsula on April 26, 2019. Millions of Greeks flock to churches around the country this week to celebrate Easter, the country's foremost religious celebration. (Photo by Aris Messinis/AFP Photo)

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)