SUPPRESSION OF RODENTS 187 



ticeable that when white weasel-skins are 

 high-priced, and, consequently, many of these 

 animals are trapped in winter, the following 

 season will be one of excessive mischief by all 

 the smaller rodents. 



L. C. Cummins, of Riverside, Cal., writing to 

 the Biological Survey, February 12, 1892, says : 



At one nursery we were bothered with gophers ; all 

 at once the gopher became scarce and from one to five 

 weasels could be seen nearly every day running 

 through the nursery stock and over an adjoining hill. 

 They completely drove away and killed all the 

 gophers. 



Useful aid by birds of prey. A similar ac- 

 count might be made of the birds not only 

 birds of prey, of which the owls and the marsh- 

 hawk are to be put foremost, but shrikes 

 (butcher-birds), crows, jays, roadrunners, gulls 

 and several of the heron tribe. Bitterns, egrets, 

 cranes and the like, search steadily for mead- 

 ow-mice. In California the great blue heron is 

 protected on many ranches in realization of 

 valuable service. A letter to The Pacific Rural 

 Press, Oct. 23, 1897, from W. M. Bistoe, re- 

 lated that a neighbor found barn-owls had 



