John W. Durban is a research biologist for the Protected Resources Division of the NOAA Fisheries Service, Southwest Fisheries Science Center, La Jolla, California.
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.