National Geographic reporter Bryan Christy commissioned two fake elephant tusks embedded with GPS, then planted them to track ivory smuggling routes from the Central African Republic into Sudan.
As with blood diamonds, the ivory is used by armed groups like Joseph Kony's Lord's Resistance Army to buy weapons and medicine. The trackers showed that ivory on this route was hand-carried through the jungle, then likely driven into Sudan, where the ivory was either stored or the GPS devices were disabled.
Ivory's Human Toll is September's National Geographic cover story, and Warlords of Ivory is their in-depth documentary about the slaughter of 30,000 elephants a year.