Timm's career has focused on managing wildlife damage and providing science-based advice for people to solve conflicts between humans and wildlife, which increasingly arise as both human and wildlife populations expand. One of his research subjects was finding better ways to prevent coyotes from preying on sheep.
He compiled, edited and published the reference book “Prevention and Control of Wildlife Damage” in 1983 and co-edited the 2004 revision. Since 1989, he has served in many leadership roles on the Vertebrate Pest Council, including managing editor of the Vertebrate Pest Conference Proceedings since 2002.
In 2007, Timm planned the first Urban Coyote Symposium and published papers from the symposium as a management guide. He also created the website CoyoteBytes.org to provide current, science-based management recommendations to wildlife managers and decisionmakers at the city, county and state levels who were dealing with urban coyote conflicts.
As director of the Hopland Research & Extension Center, he was instrumental in the design and construction of Rod Shippey Hall, an outreach and research facility that was completed in 2012. The late Rod Shippey was a UCCE advisor in Mendocino County.
Timm earned a B.S. in biology at the University of Redlands and master's and Ph.D. in ecology at UC Davis. He began his career at the University of Nebraska at Lincoln, where he served for nine years as Cooperative Extension vertebrate pest specialist and assistant professor. In 1987, he returned to California to become the second administrator in the history of the “Hopland Field Station,” as it was then known. The late Al Murphy served as the center's first administrator from 1951 to 1986.
In retirement, Timm and his wife Janice plan to stay in Ukiah and spend more time gardening, fishing, traveling and attending Giants games. Timm, who has been granted emeritus status, also plans to finish several publications and continue participating in the Vertebrate Pest Council.