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The Eastern Woodrat (Neotoma Floridana) in Southern Illinois

其他書名	Assessment of Preexisting and Reintroduced Populations
出版	Southern Illinois University Carbondale, 2008
URL	http://books.google.com.hk/books?id=1w3ZPgAACAAJ&hl=&source=gbs_api

註釋The eastern woodrat, Neotoma floridana, is a small mammalian species that has been driven to the brink of extirpation in Illinois due to habitat fragmentation, its location at the periphery of its geographic range in southern Illinois, and other factors. Only four naturally occurring populations are currently known to exist in Illinois: Pine Hills, Fountain Bluff, Horseshoe Bluff, and Little Grand Canyon. Translocations were undertaken to establish four new populations in southeastern Illinois. Woodrats were livetrapped bimonthly at three sites: Pine Hills, Fountain Bluff, and an introduced population at High Knob in Gallatin County, Illinois. At each site the minimum number known alive was calculated at monthly intervals and an assessment of reproductive condition of adult woodrats was made. At Pine Hills, 37 individuals were captured 60 times in a total of 560 trapnights; 26 woodrats were adults, 6 were subadults, 4 were juveniles, and 1 was of indeterminate age at the time of first capture. At Fountain Bluff, 19 individuals were captured 50 times in a total of 880 trapnights; 11 woodrats were adults, 2 were subadults, 5 were juveniles, and 1 was of indeterminate age at the time of first capture. The proportion of juveniles captured was greater than that observed in the 1990s. The trap success for both Pine Hills and Fountain Bluff was about one-third of that recorded in the mid 1990s. At High Knob, 24 individuals were captured 47 times in a total of 280 trapnights; 19 woodrats were adults, 2 were subadults, and 3 were juveniles at the time of first capture. Twenty-two individuals (91.6 %) at High Knob were not originally translocated there indicating successful reproduction and dispersal. Sex ratio and the number of recaptures differed between two trapping locations at High Knob. Further monitoring of the High Knob population and adjacent populations is necessary to determine the viability of the introduced populations of woodrats in southeastern Illinois.