VARIATION IN GASTROINTESTINAL CHARACTERISTICS OF MALE AND FEMALE WHITE-TAILED DEER - IMPLICATIONS FOR RESOURCE PARTITIONING

We assessed variation in intestinal lengths and gut capacity of white- tailed deer (Odocoileus virginianus). We hypothesized that differences in morphology of males and females could have important implications relative to intersexual variation in patterns of habitat use and forag e acquisition. Deer were collected from study areas in McCurtain Co., Oklahoma, and Howard and Pike counties, Arkansas. Populations of white -tailed deer in McCurtain and Howard counties were in poorer nutrition al condition than deer in Pike Co. possibly because of competitive int eractions with cattle stocked on study areas in McCurtain and Howard c ounties. Lactating females had longer gastrointestinal tracts and more digesta within their rumens and intestines than did males in summer a nd winter. Lactating females also had longer intestinal tracts and mor e digesta in rumens and intestines than did pregnant females during wi nter. Nonpregnant females in winter were primarily fawns with low body mass, but did not differ from adult females or males relative to gast rointestinal characteristics. Females collected from Pike Co. in winte r had less digesta in rumens and intestines than did other populations . Additionally, deer collected from Pike Co. in winter had proportiona tely less digesta in rumens and more digesta in intestines than other populations. Our findings indicated that sexual segregation of populat ions of white-tailed deer in summer results from females attempting to maintain maximum volume of digesta in gastrointestinal tracts; winter segregation might be influenced by dietary selection.