September, 1943 Brown & YEAGER: 
tion in the streams. During the survey, 
this difference in food habits was frequent- 
ly commented upon by veteran trappers. 
Food, in turn, apparently has a con- 
siderable effect on fur quality. Stream 
muskrats, probably because of a deficiency 
of quality foods, and possibly because of 
food shortage, yield pelts known to trap- 
pers and to the fur trade as “papery.” 
SURVEY OF Fur RESOURCE 
457 
1939, limited the taking of muskrats to 
spring traps having a jaw spread of not 
over 6 inches. The 1937 code did not 
limit the size of jaw. The codes put into 
effect in both these years specified that 
a trap might not be set or placed within 
10 feet of any muskrat house or den, but 
trapping nearer than this distance was 
found to be a common practice. “There 
Fig. 16.—Grazed ditch with eroding banks, Champaign County. Such waterways produce 
little muskrat food; burrows are often destroyed by stock. 
The leather of these pelts is thin, the hair 
color is a lighter brown and the fur is 
neither so long nor so thick as that of 
marsh muskrats. Fur buyers commonly 
pay 10 to 20 per cent more for marsh or 
ditch-grown pelts than for “papery’’ skins. 
Water contaminated with oil sludge or 
residues from coal mines destroys plant 
life, thus reducing habitat quality. Also, 
it is frequently noticed that muskrats may 
be scarce along, or absent from, streams 
contaminated by mine wastes, and from 
both streams and ditches subject to heavy 
grazing, fig. 16. Pollution has damaged 
to varying degrees the muskrat habitat 
along the Rock, Galena and upper Illinois 
rivers and around the centers of oil activi- 
ty throughout the Gray Prairie Region. 
Trapping.—The Illinois Game Code 
in effect for the 2 years beginning July 1, 
was no limitation of take in any of the 
three zones in either year of the survey. 
Spearing and shooting of muskrats were 
properly illegal, but, as the regulation 
respecting these methods of kill is difficult 
to enforce, some muskrats were so taken 
in both 1938-39 and 1939-40, Because 
their numbers could not be ascertained, 
they were not considered in the data. 
Water sets, unbaited or “blind,” are 
the standard with Illinois muskrat trap- 
pers. Traps are placed in runs at the 
entrance of holes, dens or houses, on logs, 
stumps or floating chunks, and at feed 
beds. Usually some provision is made for 
drowning the animals, in order to reduce 
the percentage of escapes effected by 
wringing off a foot. The staking of traps 
in or toward deep water and the use of 
large, heavy traps are the most common 
