Birds can be a substantial regulatory influence toward the suppression of destructive insects in California's forests, according to this report from the Division of Biological Control, Department of Entomology and Parasitology, U.C., Berkeley. The Mountain Chickadee reduced an overwintering (and epidemic) population of lodgepole needle miner in Mono County by 30% during the winter of 1961–62. Grosbeaks were also observed feeding on the sawfly larvae in the Mount Shasta area. The role of the woodpecker in reducing bark beetle infestations is also being studied at Blodgett Experimental Forest, El Dorado County, as part of this long-term ecological research project to determine feeding habits and factors influencing population levels of various forest birds.