Our Lh'iiif; RcvdH/'ccv — Mainiiuils 



11)9 



population parameters, behavior, and inabitat 

 use in the context of present and historical habi 

 tat quality and availability. 



Most research on badgers has been limited 

 to the western United States. Although results 

 have varied somewhat among these studies, 

 average densities (estimated subjectively from 

 mark-recapture and home range data) have 

 ranged from 0.38 to 5 badgers/kiii- {0.98-12.9.S 

 badgers/mi-). We use radio telemetry to colled 

 intensive data at a field site in west-central 

 Illinois. Preliminary results suggest that indi- 

 vidual badger home range size in Illinois is an 

 order of magnitude larger than that of western 

 badgers, implying that badger density in Illinois 

 is much lower The home range size estimates 

 of two badgers in Minnesota were also larger 

 than those reported for western states (Sargeant 

 and Warner 1972; Lampe and Sovada 1981 ). 



More than 65% of the Illinois landscape is 

 under intensive row-crop agriculture (Neely and 

 Heister 1987). Although badger prey exist 

 throughout Illinois, available prey in row crops 

 is limited to small species such as the deer 

 mouse {Pcnwiy.sciis manicidatits). which occur 

 in low uniform densities. Important prey species 

 reported in the West, such as ground squinels 

 (Spennophihis spp.), have average densities 

 similar to Illinois deer mice, but they are much 

 larger animals and may be concentrated into 

 easily hunted loose colonies (Messick and 

 Homocker 1981; Minta 1990). 



In Illinois, badgers appear to use most fre- 

 quently cover types that are relatively undis- 

 turbed by plowing, including hayfields, pas- 

 tures, and linear habitats such as roadsides and 

 fencelines. These habitats offer the greatest con- 

 centration of small mammalian prey and the 

 lowest frequency of agricultural disturbance. If 

 badgers are limited by available prey, it is pos- 

 sible that the current badger population density 

 is lower than when native prairie and its accom- 

 panying prey species" populations dominated 

 the landscape. 



Although badgers are legally protected in 

 Illinois, human-induced mortality such as vehi- 

 cle collisions and agricultural accidents take a 

 toll on populations. Large predators that might 

 prey on adult badgers, such as the black bear 

 (Ursus awericaniis). gray wolf (Canis lupus). 

 and mountain lion {Felis concolor), have been 

 extirpated since the 19th century (Hoffmeister 

 1989). However, our study shows that predation 

 by coyotes {Canis latrans) and domestic dogs 

 significantly affects juvenile badgers; fewer 

 than 70% of juveniles survive to dispersal, 

 reducing overall recruitment. 



The badger"s range may be expanding east- 

 ward from its fomier boundaries within the 

 Midwest; observations of range expansion in 

 Missouri, southern Illinois. Indiana, and Ohio 



American badger (Taxidea tuxus). 



suggest that agricultural practices have converted 

 previously forested acres to more suitable badger 

 habitat (Moseley 1934; Leedy 1947; Mumford 

 1969; Hubert 1980; Mumford and Whitaker 

 1982; Long and Killingley 1983; Gremillion- 

 Smith 1985; Whitaker and Gammon 1988). 



Our study revealed that badgers are distrib- 

 uted and breeding throughout Illinois. The 

 dynamics of badger range expansion are diffi- 

 cult to pinpoint, in part because of the cryptic 

 nature of the species. In Illinois and probably 

 the agricultural Midwest in general, individual 

 badgers move over such large areas that live 

 sightings or indications of badger presence are 

 few and far between. Oppoitunistic observa- 

 tions to evaluate local badger distribution 

 underestimate geographic range; thus, a focused 

 regionwide attempt to evaluate badger range in 

 the Midwest might demonstrate a wider distri- 

 bution than expected. 



Badgers in Illinois appear to be a species with 

 intermediate status: though they are neither 

 abundant nor of high economic value, they are 

 widely distributed and have adapted to a greatly 

 altered environment. Understanding what factors 

 cause a species such as the badger to become 

 more or less abundant is vitally important in con- 

 servation biology and wildlife management. 



References 



Burger. G.V. 1978. Agriculture and wildlife. Pages 89-107 in 

 H.P. Brokaw. ed. Wildlife and America. Council on 

 Environmental Quality. Washington. DC. 



Erickson, D.W. 1982. Estimating and using furhearer harvest 

 information. Pages 53-66 in G.C. Sanderson, ed. Midwest 

 furhearer management. Central Mountains and Plains 

 Section of The Wildlife Society. Wichita, KS. 



Gremillion-Smith. C. 1985. Range extension of the badger 

 {Tuxiiiea mxii.s) in southern Illinois. Transactions of the 

 Illinois Academy of Science 78:1 1 1-1 14. 



Hoffmeister, D.F. 1989. Mammals of Illinois. University of 

 Illinois Press. Urbana, IL. 348 pp. 



Hubert. G.F., Jr. 1980. Badger status evaluation. Illinois 

 Department of Conservation. Job Completion Report. 

 Federal Aid Project W-49-R-34. Study XII. 12 pp. 



Lampe. R.P., and M.A. Sovada. 1981. Sea.sonal variation in 

 home range of a female badger (Taxiilai laxiis). Prairie 

 Naturalist 15:55-58. 



Leedy, D.L. 1947. Spermophiles and badgers move east- 

 ward in Ohio. Journal of Mammalogy 28:290-292. 



