328 Bulletin- 81 



natural enemies 



Owls, large hawks and coyotes are animals that prey upon rabbitj; 

 and other animal pests, such as prairie-dogs, gophers, rats and mice. 

 Hawks (except the small "darters" or chicken hawks) and owls should 

 be protected. They are very valuable in destroying harmful animals and 

 they do practically no damage. Once the rabbits are materially reduced 

 in number or nearly exterminated by drives, trapping and poisoning, thes? 

 animals will usually ke?p them in such check that their damage will be 

 negligible. GOPHERS 



The following formula for the control of gophers is recommended b\'- 

 fhe U. S. Department of Agriculture Bureau of Biological Survey: 



DIRECTIONS FOR DESTROYING POCKET GOPHERS 



*Tocket gophers are readily caught in several makes of special traps 

 commonly on the market, and a few of these suffice to keep small areas 

 free of these pests. For ridding alfalfa fields, orchards, and long stretcher 

 of ditch embankments of them, a very successful and much more practi- 

 cal method is to poison them by placing baits of sweet potato or of pars- 

 nips in their underground runways. 



"The baits should be cut about an inch long and a half inch square, 

 and washed and drained. From a pepper box slowly sift % ounce of 

 powdered strychnine (alkaloid) and 1-10 of this quantity of saccharine 

 (ground together in a mortar or otherwise thoroughly mixed) over about 

 four quarts of the dampened baits, stirring to distribute the poison evenly. 



"The runways, which are usually 4 to 8 inches beneath the surface, 

 can be located by means of a probe made of any strong handle an inch in 

 diameter and 36 inches long. One end should be bluntly pointed. Into 

 the other should be fitted a piece of -)/« inch iron rod, protruding about 12 

 inches, and bluntly pointed. A foot rest aids in probing in hard soils. By 

 forcing down this iron rod near gopher workings, or a foot or two back 

 of fre^h mounds, the open tunnel can be felt as the point breaks into it. 

 The blunt end of the instrument is now used to carefully enlarge the 

 hole, a bait or two is dropped into the run and the probe hole closed. 



"One soon becomes expert in locating the runs, and a man can treat 

 300 to 500 gopher workings in a day. Baits need be placed only two 

 places in each separate system of 10 or 30 mounds, which is usually the 

 home of a single gopher. In our experience baits placed fairly in the op mi 

 runs have invariably killed the gophers. The method has found great 

 favor wherever it has been introduced." 



The writer has used poisoned bait made from sweet potatoes accord- 

 ing to this formula and foundj it to be entirely satisfactory. He has also 

 given demonstrations 'n making and using this poisoned bait and reports 

 of satisfactory results have been received. Messrs. D. A. Gilchrist and 

 Duane Stonier, assistants in the extermination of predatory animals, with 

 the U. S. Biological Survey, rendered excellent assistance in this work 

 during the fall of 1916 and winter of 1916-17. 



