Enumeration of muskrat dwelling houses in the bottomland lakes of the Illinois River 
valley during the 1939-1940 and 1940-1941 trapping season, table 9, revealed averages of 0,34 
and 0,35 house per acre of water area, Table 10 shows that at Rice and Chautauqua lakes the 
average number of muskrats trapped per house was 2,27, This number is comparable to the 2.9 
and 2,6 muskrats trapped per house at the Sand Lake National Wildlife Refuge in South Dakota 
(Aldous 1947), but is much higher than the 0.67 to 1,10 trapped per house at the Blackwater 
National Wildlife Refuge in Maryland (Dozier et al. 1948), 
Table 9.--Number of muskrat houses per acre on various areas in 
Illinois River valley during 1939-1940 and 1940-1941 trapping seasons, 
Houses Per Acre 
Acres in 
ee Lake Basin 
1940-41 
Sogn OS0no 7OScoCLenae F 0.32 
Cote reer etree eeeeee 
Woadmlasnlake,. oo. cassie sscsicseces 
RAGE IEA Cowie c ce sccee cs eacewee 
Lake Chautauqua,,............. 
Mite Paes esccusasesscorsssc 
iSayeseeigal | Gr <8 a erase cee Sanne 
DAML SLANG oo soscisieg sisivencis.ce ess 
POSE IE Gln tos Soe paisa isisiceisisiiea Seis 
Table 10.--Number of muskrats trapped per house at Rice Lake and 
Lake Chautauqua, 1939-1941, 
Muskrats 
Per House 
1939-40 
1940-41 
Sree 1940-41 
ee eeereesee 
19 
