James A. Estes grew up in southern California and received his bachelor’s degree from the University of Minnesota in 1967 and doctorate from the University of Arizona in 1974. For most of his career, he worked as a research scientist for the US Geological Survey. In 2007, he retired from federal service and joined the Department of Ecology and Evolutionary Biology at the University of California, Santa Cruz. His pioneering work on the role of sea otters as keystones in kelp forests is now a classic example of a trophic cascade. Estes has conducted research on coastal marine ecosystems in Alaska, California, Canada, Mexico, New Zealand and Russia. His most recent book, a memoir entitled "Serendipity: An Ecologist’s Quest to Understand Nature," was published in May of 2016.

He is a Pew fellow in marine conservation, a Fellow of the California Academy of Sciences, and a member of the U.S. National Academy of Sciences. He received the Western Society of Naturalist’s Lifetime Achievement Award in 2011 and the American Society of Mammologists C. Hart Merriam Award for excellence in research in 2012.