1-4 



COMMON MAMMALS OK \V KS'I'KK N MONTANA. 



orchard on top of (he bench. The chief engineer of the Bitterroot 

 Valley Irrigation Co. writes that in 1011 $184.75 was spent to pro- 

 tect the company's main irrigation ditch and that each of the numer- 

 ous development camps waged its own war against the squirrels. 



The Columhian ground squirrels are probably the most difficult 

 of the native rodents to poison. The chief reasons for this are that 

 the animals prefer green vegetation to grain, that they do not store 

 food, that they have an intense dislike for bitterness, and that they 

 for some cause refuse to eat arsenic baits. For these reasons several 

 years of experimenting have failed to produce a bait which is 

 effective on the Columbian ground squirrels when green vegetation is 

 abundant. But the work done during li)ll indicates that these ani- 

 mals can be successfully poisoned if the poison is placed early in 

 the spring when they first come out of hibernation. This means that 

 the baits must usually be put out not later than the 1st of April and 

 that they will not succeed after vegetation is well started. 



Hulled oats (or "groats," as they are technically known) are 

 preferred by these squirrels to all other forms of grain and are 

 much better than wheat for use in poisoning. Groats can be secured 

 at oatmeal mills, usually at a cost of about 3 or 4 cents a pound. 

 Ordinarily in the process of manufacture the groats are raised to a 

 high temperature in coffee roasters, but the unroasted grain is better 

 for squirrel bait, and should be secured where possible. Although 

 hulled oats are more expensive than wheat, they should nevertheless 

 be used, for they will give better results. Individual ranchmen 

 making up small quantities of poison are likely to have difficulty in 

 securing groats — another argument in favor of the wholesale manu- 

 facture and retailing of squirrel poison by associations. 



Care should always be taken to avoid poisoning useful birds, and 

 in some cases a special "bird-proof" preparation is necessary. The 

 poison which best meets these requirements is a small square "bis- 

 cuit " of poisoned material, which when dry is too hard for small 

 birds to peck to pieces and too large for them to swallow whole. 

 These baits require considerable time to prepare, and therefore cost 

 more than poisoned grain; but they are effective and are the only 

 baits which will not endanger birds. They are, moreover, more 

 resistant to rain than loose grain. 



The following preparations are recommended, but must be used 

 early in the spring : 



POISONING COLUMBIAN GROUND SQUIRRELS. 



FORMULA I. POISONED GROATS. 



Hulled oats ("groats") 



Strychnine alkaloid (powdered) 



Flour 



Cold water 



4 quarts. 



I ounce 



5 level tables poonfuls. 

 1 cup. 



1M 



