Nepal has had remarkable success at tackling the poaching of its greater one-horned rhinos but, since 2015, it has witnessed a sharp increase in deaths from unknown or natural causes.
New technology detects the shockwave of a supersonic bullet traveling through space, which cannot be muffled, to track poachers shooting at elephants and rhinos.
In 2005, conservationists launched a plan to establish rhino populations in seven parks in Assam state. It proved to be an even bigger challenge than expected.
As poaching pushes the rhino toward extinction, South Africa considers a radical solution: Legalize the very thing that is killing them. It'd make some people very rich. But would it doom the species?