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)

An Egyptian security guard screams at people as medics bring in a stretcher to carry the wounded after the attack which killed President Anwar Sadat, October 6, 1981, as he watched a military parade. (Photo by AP Photo)

London's Regent Street was transformed into a festive wonderland as over 800,000 revellers enjoyed the Hamleys annual Christmas Toy Parade on November 19, 2017 in London, England. (Photo by Tristan Fewings/Getty Images for Hamleys)

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)

A combination photo shows various popular street foods under $6 from various hawker food stalls and eateries in Singapore, taken between July 28 to 31, 2016. Top row (L to R) bak chor mee, soya sauce chicken; Middle row (L to R) laksa, hokkien mee, nasi lemak, ice kachang; Bottom row (L to R) rojak, roti prata and satay. (Photo by Edgar Su/Reuters)

A Great White Pelicans eats fish in the Mishmar HaSharon reservoir, Israel, Wednesday, November 4, 2015. Thousands of Pelicans stop in the reservoir for food provided by the Israeli nature reserves authority as they make their way to Africa. (Photo by Ariel Schalit/AP Photo)

Residents with faces covered in ash ride on a motorcycle as Mount Sinabung volcano erupts, in Sukandebi village in Karo Regency, Indonesia's North Sumatra province, Indonesia June 13, 2015, in this photo taken by Antara Foto. (Photo by Rony Muharrman/Reuters/Antara Foto)

“The Atlas moth (Attacus atlas) is a large saturniid moth found in the tropical and subtropical forests of Southeast Asia, and common across the Malay archipelago. Atlas moths are considered the largest moths in the world in terms of total wing surface area [upwards of c. 400 cm2 (62 sq in)]. Their wingspans are also amongst the largest, reaching over 25 cm (10 in). Females are appreciably larger and heavier”. – Wikipedia. Photo: Atlas Moth. (Photo by Terri Oda)