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)

The fourth annual BigPicture Natural World Photography Competition aims to celebrate the diversity of life on Earth, and encourages people to protect and conserve it. Here: “The Salmon Catchers”. Terrestrial Wildlife. To capture this view of a mother grizzly bear and her cub, photographer Peter Mather set up a camera trap on a log that he knew the bears tended to traverse while fishing for salmon, in the Yukon River watershed in Canada. (Photo by Peter Mather/BigPicture Natural World Photography Competition 2017)

The Intel logo is projected on the face of Intel Executive Vice President Dadi Perlmutter as he speaks during a news conference about the 3-D Tri-Gate transistors called “Ivy Bridge” on May 4, 2011 in San Francisco, California. Intel announced a technical breakthrough in the microprocessors with the world's first Tri-Gate transistors, that will increase speed and consume less energy. (Photo by Justin Sullivan/Getty Images)

David Yeo’s photography places naturally small species alongside animals that have been selectively bred to be tiny and cute. Here: “The most difficult aspect of this shoot was to get each African pygmy dormouse – also known as micro squirrels – on to a separate camera. Once in place, they needed to remain still long enough to get them both in the frame and looking at me. Often solitary, they naturally wanted to move away”. (Photo by David Yeo/Leica Studio Mayfair/The Guardian)

A Aldabra Tortoise receives a Christmas treat at Taronga Zoo on December 14, 2012 in Sydney, Australia. Taronga Zoo celebrated Christmas early giving Christmas-themed environmental activities to the Zoo's Giraffes, Sun Bears, Meerkats, Aldabra Tortoise and Cockatoos providing a wonderful natural display for Zoo visitors. (Photo by Lisa Maree Williams)

Elements of nature are too powerful for humans to subdue, yet it didn’t stop the most courageous individuals from trying. Conquering air, land, fire, water, and even the very fabric of reality – this is the ultimate goal of humanity. For now, we can only marvel at the beauty and tremble in awe before the Mother Nature. A short film “Ocean Gravity,” written and directed by Julie Gautier and Guillaume Nery, reminds us of how small and insignificant a human body is, as it is being swept away by an ocean current. Nevertheless, it never stopped people from attempting to subjugate these unstoppable forces, and someday, maybe the humanity will come out victorious.

This picture shows a two-year old orangutan seized from a residents house at the provincial Nature Conservation and Agency (BKSDSA) office in Banda Aceh on September 16, 2014. The critically-endangered primates population are dwindling rapidly due to poaching and rapid destruction of their forest habitat that is being converted into palm oil plantations. (Photo by Chaideer Mahyuddin/AFP Photo)