ST. LOUIS (KTRS) — St. Lous Zoo president and C-E-O Dr. Jeffrey Bonner announced Wednesday he is retiring at the end of the year after 19 years on the job. The St. Louis Zoological Park Subdistrict Commission has begun the process of an international search to identify Dr. Bonner’s successor in the coming months. Since Dr. Bonner joined the Zoo in 2002, more than 56 million guests have been introduced to the wonders of the natural world by visiting the Zoo.  Under Dr. Bonner’s leadership, the Zoo created an endowment in 2004 that was valued at $93.2 million as of January 31.