"Esmond was one of conservation's great unsung heroes," Save The Elephants founder Iain Douglas-Hamilton said.
Amur tigers have the personal backing of Vladimir Putin.
If their status changes, protections for the leatherbacks could be reduced.
One account said this was the worst animal welfare violation she'd ever seen.
Breeding endangered animals is part of a zoo's "species surival plan."
Despite legal protection, North Atlantic right whales keep getting struck accidentally by fishing boats and entangled in gear.
In the Russian Far East, scientists thought they had spotted a tiger flee shelter from the snow, possibly spooked by a much smaller female leopard sleeping inside.
The scientists hope they weren't interrupting a courtship session.
The exact cause is still a mystery, though a prime suspect has been named.
eBay has hundreds of listings for taxidermy bats, and Etsy has nearly a thousand.
This giant rat is gold-colored, a foot and a half long, and was just a rumor among scientists for decades.
Sea turtle populations seem to be on the rebound after decades of work.
The video was shot in November last year and has just been released after expert analysis.
Baculovirus forces its caterpillar host to climb up trees before it bursts out to infect others on the ground below.
Donald Trump may be cutting funding to the environmental sciences, but one near-endangered butterfly is thriving.
The largest study of Javan rhinos suggests these beasts are hovering on the edge of extinction.
The animals are different to study as they live in harsh climates in politically unstable regions.
An analysis of lion teeth reveals why they attacked and ate dozens of railway workers 100 years ago.