104 RODENTS OF IOWA 



terially, the number of animals may before long be reduced to a 

 point where the species is in danger of extermination. 



The natural enemies of the muskrat include the mink, and the 

 larger hawks and owls. Of course floods, droughts and very severe 

 winters take their toll of muskrat lives, but trapping and the recla- 

 mation of swamps and marsh lands are mainly responsible for the 

 great reduction in numbers. The drainage of swamp land is being 

 carried out extensively in many parts of Iowa, and if a supply of 

 fur is to be maintained protective laws and private ownership must 

 seek to maintain the proper equilibrium. Of course it cannot be 

 denied that the land thus reclaimed is exceedingly valuable from 

 an agricultural standpoint, but farmers and owners of land on 

 which suitable muskrat habitats are found should take a part in 

 the protection of this fur-bearer and see that a fcAv places are re- 

 served for its use. 



In Iowa, the muskrat is protected from April 1 to November 1, 

 except when found damaging private or public property. It is en- 

 tirely proper that legal enactment should forbid the destruction 

 of these animals, especially during the season of reproduction which 

 the above time is designed to cover. Every one should see that this 

 law is strictly enforced. Spearing, shooting, and the destruction 

 of houses should not be tolerated in any community where the ani- 

 mals are not sufficiently numerous to do material damage ; and if 

 they are properly protected they will furnish a constant source 

 of fur for many years, 



, Where muskrats are exceedingly abundant, especially in the vi- 

 cinity of canals, drainage ditches aJid embarkments of streams, 

 methods of control are sometimes required. Trapping is effective 

 in both summer and winter, but is a slow process. Shooting is ef- 

 fective for a short time, although a continuation of the practice 

 causes the animals to become exceedingly wary. Poisoning is an 

 effective method of destroying them. Powdered strychnia sulphate 

 mixed with a little powdered sugar and sprinkled over freshly 

 cut pieces of carrot or apple, has been used with considerable suc- 

 cess. Sometimes good results can be obtained by inserting crystals 

 of the strychnia sulphate into baits of apple or carrot. Great care 

 must be observed in keeping the baits where poultry or live stock 

 will not reach them. 



Wlien any such protective measures as above suggested are em- 

 ployed, it is well to confine them to the time when the fur is at its 



