On the Edge, Grevy Zebra in colored pencil by Sue Gombus. All Rights Reserved. www.suegombuswildlife.com My series "On the Edge" is a body of work depicting the worlds endangered species. After traveling to Africa may times and around the American West, I am at present traveling to American Zoos and Sanctuaries to document the endangered species found here. The endangered wildlife depicted in this series is placed specifically on an edge of the paper, as the wildlife they depict are on the edge of existence.