Richard H. Tedford, one of the foremost authorities on the evolution of the Carnivora, is now a curator emeritus in the Department of Vertebrate Paleontology at the American Museum.
Elephant populations continue to dwindle in Tanzania.
With proper safeguards, water currents can be harnessed out of sight.
Barely pulled back from the brink of extinction, California condors are still being poisoned by lead-based ammunition.
Vulnerable everywhere in the wild, lions already face regional extinction.