The World Wildlife Fund has released a report saying it has found an “astonishing” 60 percent decline in wildlife populations globally over the past 40 years, mostly because of 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 CEO 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 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 said.

Human activity has had an effect on oceans, forests, coral reefs, wetlands and mangroves, the report said. The globe has lost about half its shallow-water corals in the past 30 years.

“From rivers and rain forests, to mangroves and mountainsides, across the planet our work shows that wildlife abundance has declined dramatically since 1970,” said Ken Norris, director of science at the Zoological Society of London, which provided one of three indexes used to write the report. “The statistics are scary, but all hope is not lost. We have an opportunity to design a new path forward that allows us to coexist sustainably with the wildlife we depend upon.”

As an example of the trend, Temple University biologist S. Blair Hedges reported Tuesday in the Proceedings of the National Academy of Sciences that he and a team of researchers had found a near-total loss of Haiti’s primary forest and a mass extinction of species. Hedges and his colleagues scrutinized aerial photography and Landsat images from 1988 to 2016, finding that forests covered 4.4 percent of Haiti’s land in 1988. That plunged to 0.32 percent by 2016.

More positively, the World Wildlife Fund report said habitat restoration and other actions have worked, citing population increases in giant pandas, mountain gorillas and endangered dolphins.

It singled out the U.S. Endangered Species Act of 1973 as helping “an estimated 99 percent of listed species avoid extinction.”

Among other findings:

• Habitat suitable for mammals dropped 22 percent from 1970 to 2010, with the greatest declines in the Caribbean, where it exceeded 60 percent.

• The index measuring extinction risk for birds, mammals, amphibians, corals and cycads (an ancient group of plants) showed declines for all groups, with species moving more rapidly toward extinction.

• Humans have already pushed some areas beyond their limits through climate change, loss of biosphere, nitrogen and phosphorus flows, and land-use change.

• Ninety percent of the world’s seabirds are estimated to have plastic fragments in their stomachs.

Philadelphia Inquirer