A Pioneer Lost: Groundbreaking Wildlife Researcher Killed Listen Download Embed Share Share this on Facebook (Opens in a new window) Share this on Twitter (Opens in a new window) Share this via Email Esmond Bradley Martin, an investigator known for his groundbreaking work in exposing the ivory and rhino horn trades. ( Save the Elephants/Twitter ) Produced by Dana Roberson Hosted by Todd Zwillich Produced by PRI and WNYC