Demonstrators wear skull masks during an anti government protest, as Chile's President Michelle Bachelet delivers a speech inside the National Congress, in Valparaiso city, Chile May 21, 2016. (Photo by Ivan Alvarado/Reuters)

People who fled the violence from Islamic State-controlled northern Syrian town of al-Bab arrive in the rebel-held outskirts of the town, Syria February 3, 2017. (Photo by Khalil Ashawi/Reuters)

Tina Hitscherich surprises a police officer with a kiss during the NYC Pride Parade in New York, Sunday, June 26, 2016. With a moment of silence followed by the roar of motorcycles, New York City's gay pride parade kicked off Sunday, a celebration of barriers breached and a remembrance of the lives lost in the massacre at the gay nightclub in Orlando. (Photo by Seth Wenig/AP Photo)

A man dressed in a traditional Perchten costume and mask performs during a Perchten festival in the western Austrian village of Huben November 22, 2014. Each year in November and January people in the western Austria regions dress up in Perchten (also known in some regions as Krampus or Tuifl) costumes and parade through the streets to perform a 1,500 year-old pagan ritual to disperse the ghosts of winter. (Photo by Dominic Ebenbichler/Reuters)

Global wildlife populations will decline by 67% by 2020 unless urgent action is taken to reduce human impact on species and ecosystems, warns the biennial Living Planet Index report from WWF (World Wide Fund for Nature) and ZSL (Zoological Society of London). From elephants to eels, here are some of the wildlife populations most affected by human activity. Here: The maned wolf is among the large mammals in the Brazilian Cerrado that are threatened by the increasing conversion of grasslands into farmland for grazing and growing crops. (Photo by Ben Cranke/Nature Picture Library/Alamy Stock Photo)

Residents watch the ocean waves crash into the water front, after the passage of Hurricane Irma, in Cuba, Sunday, September 10, 2017. (Photo by Ramon Espinosa/AP Photo)

British tourists snap a cheeky selfie with a monkey at the Ubud Monkey Forest in Bali, Indonesia, August 4, 2015. George Benton, 22, from Paignton, Devon was visiting the Sacred Monkey Forest Sanctuary in Ubud, Bali whilst traveling with his girlfriend Chloe when the couple snapped a surprise shot with Balinese long-tailed monkey using a “selfie stick”. “We couldn't believe our luck when we looked back at the photos, he looked straight into the camera!” said George, who went on to reward the cheeky chap with a banana for giving the couple such a memorable photo. (Photo by George Benton/Splash News)