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 juvenile leopard cat, seized by authorities during an anti-smuggling operation, is seen past suspected smugglers during a press conference announcing the seizure of trafficked exotic animals in Surabaya on March 27, 2019. Indonesian authorities said March 27 they had seized five komodo dragons and dozens of other animals being sold on Facebook, as the country battles to clamp down on the illegal wildlife trade. (Photo by Juni Kriswanto/AFP Photo)

An orphaned giraffe nuzzling a wildlife keeper at Sarara camp in Kenya, one of 70 pictures being sold by Prints for Nature (printsfornature.com) to raise money for work by the Conservation International charity. This giraffe was rehabilitated and returned to the wild, as a number of others have done before him. Right now, giraffe are undergoing what has been referred to as a silent extinction. Current estimates are that giraffe populations across Africa have dropped 40 percent in three decades, plummeting from approximately 155,000 in the late 1980s to under 100,000 today. (Photo by Ami Vitale/National Geographic)

These tiny little sugar gliders are lucky to be alive after surviving a cat attack that killed their mother. Somehow the youngsters, who were just a few days old at the time, and the size of jellybeans, survived and were rushed to the Currumbin Wildlife Hospital in Queensland, Australia. (Photo by Adam Head/Newspix/REX Features)

Anne London found her focus at the age of 19 while working for Tippi Hedren, founder of Shambala , a refuge for big cats, elephants and other species located in California. There, as she walked among the animals, she realized that the commercial art field was not for her, and she dedicated her life to bringing about awareness of the plight of endangered wildlife across the globe, and raising money for conservation efforts.

Photographer David Lazar captured photos of native Dessana tribe, nearly 3,000 miles away from Brazil's capital. Tribe is only accessible by boat from city of Manaus. Surrounded by trees, waterfalls and tropical wildlife, this Amazon tribe is a world away from the beaches of Rio.

David and Lana Fechter have recently adopted two adorable Siberian bear cubs that were rejected by their mother at a Chicago zoo. The two nine-week-old male cubs, Lewis and Clark, are being kept in an inside closure and are being bottle fed. When the twins get bigger and more independent, they’ll be be given a large natural enclosure with ponds and ridges to live in at Shalom Wildlife Sanctuary.

American nature and wildlife photographer Paul Souders is very well-travelled around the globe. In one of his exploits, we have his series of images shot in the ice capped shores of Churchill, Canada. Souders took his Zodiac boat to Hudson Bay in midsummer and waited there for three days before he finally saw a bear, a young female while on sea ice around 30 miles offshore.