1936] MAMMALS OF OREGON 217 



eaten, but there is no evidence that fish are ever captured for food. 

 Muskrats rarely show much fat but are generally plump and well 

 muscled. Their flesh is excellent food if properly cooked and brings 

 a good price in the large city markets. 



Economic status. At present muskrats are kept scarce in most of 

 the waters of eastern Oregon by vigorous trapping for their fur, but 

 in Malheur Lake, where given special protection on the national bird 

 refuge they have at times become normally abundant. In 1908-9, 

 from November to March, 3 trappers took 5,600 skins around Malheur 

 Lake, and other trappers took an unknown number. The next winter 

 22 trappers secured only 1,500 skins. The next winter 2 trappers 

 secured 2.000 skins and the following winter 2,258 skins, but the next 

 winter (1912-13), only 890 skins. The season was then shortened to 

 4 months, November to February, and for the 3 years following, the 

 2 trappers took 1,480, 1,736, and 1,399 skins, respectively. There were 

 a few other trappers but none making a regular business of it for the 

 whole season as did these 2. The number of skins taken at this lake 

 probably averaged 2,000 to 3,000 a year for the '8 years. 



In the winter of 1914-15 for some unknown cause most of the 

 muskrats left the lake as soon as it froze over and scattered out for 

 miles over the sagebrush valley where they died and were killed by 

 hundreds. They were poor and possibly diseased, but more probably 

 starving, as their regular food supply had been destroyed by unusu- 

 ally high water that summer. Many of the ranchers killed 100 or 

 more of the animals around their places and found others dead in 

 the sagebrush, on the ice, and even in Spring Creek, which never 

 freezes. Many thousands were estimated as killed outside of the 

 lake, and many more died that were not recovered. The next sum- 

 mer the writer saw their carcasses in the sagebrush over the valley 

 and the animals were scarce in the lake. Still with a couple of years' 

 suspension of trapping they increased again to normal numbers and 

 in 1920 were abundant in the lake. 



A much fuller knowledge of the habits and requirements of musk- 

 rats is necessary before they can be intelligently controlled, but on 

 private or public land where they can be kept at a maximum abun- 

 dance they afford a profitable fur industry. This large dark-brown 

 variety yields an especially beautiful and valuable pelt. There are 

 other lakes in Oregon that could undoubtedly be stocked with musk- 

 rats to advantage, but it should be borne in mind that under certain 

 conditions, especially in irrigated areas, muskrats are capable of 

 serious injury to ditch banks and to crops along the ditches. In such 

 localities more thorough trapping and a long open season usually 

 afford all the protection necessary and the value of the fur amply 

 pays for the control. 



FIBER ZIBETHICUS MERGENS HOLLISTEB 

 NEVADA MUSKRAT 



fiber sibetMcus meryens Hollister, Biol. Soc. Wash. Proc. 23 : 1, 1910. 



Type. Collected at Fallen, Nev., by S. E. Piper, in 1908. 



General characters. Slightly smaller than osoyoosensis and much larger 

 than pallidtis. Typical specimens from the Great Basin valleys somewhat 

 paler than O8Oyoosensi$ in comparable pelage ; upper parts dark grayish brown ; 



