Once a koala population falls below a critical point, it can no longer produce the next generation, leading to extinction.
"We didn't start doing them to not do them," David Bernhardt said of his policies to limit protections for threatened animals and to factor the cost to corporations into protecting endangered species in an interview with The Washington Post published Friday.
There are only 144 kakapos left in the world.
Insect numbers everywhere are declining—and scientists aren't exactly sure why.
Almost all animals of the 162 classified as threatened were in danger because of humans hunting the creatures for food or body parts.
Today some 500,000 bison have been restored in over 6,000 locations.
Data from Cassini's "death dive" reveals Saturn's rings could be just 10 million years old.
Warming waters around the world are turning turtles female on a massive scale.
Researchers link a supernova explosion 2.6 million years ago to the extinction of marine megafauna.
An estimated 70% of land animals and 96% of sea creatures were wiped out in Earth's biggest mass extinction.
"Killer whale populations found in the most polluted seas around Japan, Brazil, the U.K. or in the northeast Pacific, the authors report, are tending toward complete collapse."
Humans were butchering giant animals on the island more than 10,000 years ago.
These sharks are now the most popular in the ocean.
Scientists simulated global warming inside bee nests to find out what happens if the Earth continues to warm at the predicted pace.
It didn't take long for dinosaurs to take over, according to new research.
But today's threats are far more intense than those of the past.
Tiny fish remains were time capsules of climate change.
"You haven't lived until you've put your arms around a mammoth femur trying to measure it," Smith said.
Some estimates say there are fewer than 30 vaquitas left in the world.