Leif is a conservation biologist who coordinates the California Bumble Bee Atlas project. His research focuses on the ecology, distribution, and declines of North American bumble bees. Leif previously worked as an environmental consultant, studying pesticide risk to bee pollinators, and as an ecologist for Vermont Fish and Wildlife Department. He is co-author of a range of scientific publications on bees, including Bumble Bees of North America: An Identification Guide (2014, Princeton University Press), the standard reference manual on this group of insects. He is an expert in the inventory and identification of bumble bees, and has extensive experience training others to collect bumble bee distribution data in the field. Leif holds a Master’s degree from the University of Arizona and a PhD from Dartmouth College.