SREL Reprint #1134




Pre and Post Dispersal Movement Behavior of Subadult Bobcats on the Savannah River Plant

M. A. Griffith and T. T. Fendley



Six subadult bobcats (Lynx rufus) were radio-tracked on the Savannah River Plant, South Carolina, from October 1980 to July 1981.  Dispersal period and distances, as well as home range sizes and movement patterns, before and after dispersal were determined from 771 observations.  Subadult bobcats dispersed from late February to mid-March, which corresponded to the breeding season of adult bobcats monitored at the same time.  Dispersal duration varied from 2-6 days and covered an average straight line distance of 8.7 km.  Once settled, dispersing bobcats remained in their new use areas for the remainder of the study (4.5 months).  Estimated average home range size of female bobcats before and after dispersal was 3034 and 1475 ha, respectively.  Insufficient data were collected to estimate male home range size prior to dispersal, but 1472 ha was the size estimated for the period following dispersal, a value similar to females.  Average minimum total distance (MTD) moved per diel tracking period before and after dispersal was 6.8 and 4.5 km, respectively for female bobcats and 4.6 km after dispersal for the males.  Distances moved per 2 hour interval before and after dispersal averaged 593 and 394 m, respectively, for female bobcats and 442 m after dispersal for the males.  Annual activity patters suggest crepuscular movement for females, with peaks occurring from 0400-0800 hours and 1800-2200 hours.  These periods were consistent through all seasons with the exception of the dispersal period, when peak movement occurred from 0800-1200 hours and 1600-2000 hours.  Activity patters for male bobcats showed peaks occurring from 1000-1400 hours and 2200-0200 hours.  These periods were also consistent through seasons except dispersal, when peak movement occurred from 0400-0800 hours and 2000-00000 hours.  Following dispersal, home range sizes and movement patterns of male and female subadult bobcats were analogous to those of adult female bobcats being monitored at the same time.  The relatively short dispersal period and distances moved implied that vacant areas were readily available to subadults, presumably because the density of adult bobcats on the Savannah River Plant during the study was low.  These dispersal patterns may be typical of exploited bobcat populations.

Key words:  Bobcats, South Carolina, subadult, dispersal, movement

SREL Reprint #1134

Griffith, M.A. and T.T. Fendley. 1986. Pre and post dispersal movement behavior of subadult bobcats on the Savannah River Plant. p. 277-289. In Second International Cat Symposium: Cats of the World: Biology, Conservation and Management, edited by S.D. Miller and D. Everet. Ceaser Kleberg Wildlife Research Institute and National Wildlife Federation. Kingsville, TX.

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