The World Wildlife Fund has released a report saying it has found an “astonishing” 60 percent decline in wildlife populations globally over the last 40 years, mostly due to human activity, including climate change and habitat loss.

“This report sounds a warning shot across our bow. Natural systems essential to our survival – forests, oceans, and rivers – remain in decline. Wildlife around the world continue to dwindle,” said Carter Roberts, president and chief executive officer of WWF-US. “It reminds us we need to change course. It’s time to balance our consumption with the needs of nature, and to protect the only planet that is our home.”

The group’s biennial report, released Monday, said it measured trends in 16,704 populations of 4,005 species of birds, mammals, reptiles, amphibians and fish. The biggest declines were among creatures that live in fresh water, which faced an even bigger 83 percent drop. South and Central America were hit hardest as rain forests shrank, with 20 percent of the Amazon disappearing.

“Humanity and the way we feed, fuel, and finance our societies and economies is pushing nature and the services that power and sustain us to the brink,” the report states.