Alfalfa yield loss from Belding's ground squirrels in northeastern California

Belding's ground squirrels (Spermophilus beldingi) significantly impact alfalfa production in areas of northeastern California. Economic losses result from the squirrels' feeding and burrowing activities within alfalfa fields. Control relies on using burrow fumigants, applying anticoagulant baits, and shooting. We assessed yield loss from Belding's ground squirrels in alfalfa fields of Butte Valley, northeastern California, in 1995 and 1996. In 1996, percentage yield loss estimates ranged from 34.6 to 45.9% and were related to ground squirrel population size. These estimates will provide an expenditure baseline to justify management of Belding's ground squirrels.