"Blood Ivory," the lead article in the October issue of National Geographic Magazine, shed light on the plight on African elephants killed only for their prized tusks. That article, written by Delaware Valley native and Penn State graduate Bryan Christy, is the basis of tonight's episode of "National Geographic," airing at 9 p.m. today on WHYY-TV.

Despite the decades-old international ban on tusk collecting, trade in illegal ivory continues. Christy says that a one-time-only exception to the ban in 2008 to allow China to import 60 tons of stockpiled ivory opened the flood gates to smugglers.