London Mayor Boris Johnson takes part in a tug of war with members of the armed services to launch the London Poppy Day, outside City Hall, in London, October 27, 2015. London Poppy Day is a street collection event to raise money for serving and retired members of the armed services and their families. (Photo by Stefan Wermuth/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)

A couple take photographs alongside the National Monument on Calton Hill, Edinburgh on Wednesday January 5, 2022, ahead of First Minister Nicola Sturgeon's update to the Scottish Parliament on the Covid-19 situation as the Omicron variant sweeps across the country. (Photo by Jane Barlow/PA Images via Getty Images)

British television presenters Trinny Woodall (centre right) and Susannah Constantine (centre) lead almost 900 women in throwing their old bras into the air in Rothwell town square in Rothwell, Northamptonshire on May 7, 2007. (Photo by Clara Molden – PA Images/PA Images via Getty Images)

Afghans shout anti-U.S. slogans as they burn tires and block a highway during a protest in reaction to a small American church's plan to burn copies of the Quran, at Jalalabad, east of Kabul, Afghanistan, Friday, September 10, 2010. Religious and political leaders across the Muslim world welcomed a decision by the church to suspend its plans to torch copies of their holy book but some said Friday the damage has already been done. (Photo by Rahmat Gul/AP Photo)

Kendall Jenner and Kylie Jenner seen in this celebrity social media picture on September 1, 2016. (Photo by XposurePhotos.com)

Derek Hough, right, and Julianne Hough, co-winners of the award fo rOutstanding Choreography for “Dancing with the Stars”, pose in the press room at the Creative Arts Emmy Awards at the Microsoft Theater on Saturday, September 12, 2015, in Los Angeles. (Photo by Chris Pizzello/Invision/AP Photo)

A man passes by an unfinished street art graffiti made in a stairway by French street artists Zag and Sia in Paris on March 1, 2016. The two artists drew inspiration from famous “Liberty Leading the People” (La Liberte guidant le peuple) painting by French Eugene Delacroix commemorating the July Revolution of 1830 and viewed as a symbol of the French Republic. (Photo by Joel Saget/AFP Photo)