Proceedings of the Vertebrate Pest Conference

The history and development of rodent control systems in northern California, particularly in regard to ground squirrels (Spermophilus spp.) and meadow mice (Microtus californicus) are discussed, with the work of “pest abatement districts” described. A bounty system intended to control ground squirrels and pocket gophers had been enacted in 1870, it but was soon abandoned as too expensive and ineffective by most counties. In 1874, new legislation resulted in certain counties establishing Squirrel Inspection Districts while requiring landowners to control ground squirrels, but this system was neither widely adopted nor effective. Finally, in 1917 a state Rodent Control division was established that resulted in effective action, and improved methods and techniques have continued to be developed. In the late 1950s, studies of Microtus in the Tulelake Basin resulted in a better understanding of the dynamics of meadow mouse damage and population cycles, resulting in improved control strategies. County-led efforts and their effectiveness are described. Current techniques have advantages of being increasingly species specific with reduced hazards to nontarget species, particularly raptorial birds.