World Wide Fund for Nature
"This ranks as one of the worst wildlife disasters in modern history,” said Dermot O'Gorman, CEO of WWF Australia.
As scores of koalas battle to recover from Australia's destructive fires, hopeful stories of survivors are emerging.
Ecologists at the University of Sydney and WWF Australia estimate that a billion is a conservative figure.
The probe follows a BuzzFeed News investigation into anti-poaching groups funded by conservation organization World Wide Fund for Nature.
And humans are mostly to blame, according to the World Wildlife Fund's 2018 Living Planet Report.
A record number of countries and territories participated in this year's event.
Think that pic of you caressing a tiger is cool? Think again.
“Posing next to a king of the jungle doesn’t make you one."