People dressed as zombies take part in a “Zombie Walk” parade in Athens, Greece, February 25, 2017. (Photo by Michalis Karagiannis/Reuters)

Michelle Wie of the USA lines up a putt on the second hole during the final round of the HSBC Women's Champions on the Tanjong Course at Sentosa Golf Club on March 5, 2017 in Singapore. (Photo by Scott Halleran/Getty Images)

A Berber Moroccan woman, wearing traditional outfits, parades during the “Miss Rose” beauty contest as part of the yearly Rose Festival on May 13, 2016 in the town of Kelaat Mgouna, at the foot of the High Atlas Mountains in Morocco. (Photo by Fadel Senna/AFP Photo)

One of the worlds shortest models Mary Russell at 4 feet 1 inch with 6 foot model Georgia Meacham in London, UK on June 16, 2016. The 4ft1 beauty suffers with achondroplasia a medical term for dwarfism, which means she has as average sized torso but short arms and short legs, with an oversized head. As well as stifled growth, Mary also suffers with sciatica and spinal stenosis, an abnormal narrowing of the spinal canal – which cause agonising nerve problems, leaving her in excruciating pain and unable to stand for long periods of time. The condition leaves Mary, 47, struggling with everyday tasks things most people take for granted like going to the supermarket, getting cash from an ATM and ordering a drink at a bar become a challenge. (Photo by Simon Jacobs/Caters News Agency)

In this image distributed on Tuesday, September 29, 2015, 11-year old dance star Taylor Hatala and friends are seen filming their new Monster High Boo York, Boo York music video #CityGhouls in Los Angeles. (Photo by Casey Rodgers/Invision for Mattel/AP Images)

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)

Two wolfhounds take part in a dogfight in a stadium in the Kyrgyzstan capital Bishkek on November 5, 2017, during fights organized by a local breeders aiming to improve the Asian Shepherd breed, organizers said. (Photo by Vyacheslav Oseledko/AFP Photo)

A Southwest Airlines jet takes off from Reagan National Airport with a thunderhead to the east on June 20, 2017 in Alexandria, VA. (Photo by Jonathan Newton/The Washington Post)