Ocala/St. Johns Demographics
FWC researchers studied bears in the Ocala/St. Johns subpopulation from 1999-2007 to monitor adult female bears and their offspring. Survival and reproductive rates were used to estimate the growth rate of the subpopulation.
To collect detailed, individual-scale data, researchers captured bears in Ocala National Forest and nearby Lynne, Florida and fit 57 adult females with tracking collars. Researchers tracked these animals for several years to document mortalities, survival, and reproduction. When a collared female bear gave birth, biologists collared her offspring. Researchers collared and tracked 50 cubs to document mortalities and survival for cubs in their first year. See Tracking Bears to learn more about how FWC tracks and uses data from bears.
The probability of survival for adult females in Ocala/St. Johns was 91% per year, where mortalities were documented from vehicular strike, male bear aggression, and illegal kills. Survival for subadult (2-year old) females was 74% per year. The probability of survival for cubs was 38% in their first year, where most mortalities were due to predation from other bears but were also documented from abandonment and vehicular strike. The average litter size was 2.1 cubs per litter but ranged from 1 – 4 cubs. Females gave birth once every 1.8 years. Researchers calculated that the Ocala/St. Johns subpopulation was stable, varying between growth of 3.7% and decline of 1.5% per year.
The completion of the study provided FWC with baseline information to improve understanding and management of bears in the Ocala/St. Johns subpopulation. Most importantly, it showed that this subpopulation was stable despite low cub survival.
Results of this study were published in the following:
- Garrison, E. P., J. W. McCown, M. A. Barrett, and M. K. Oli. 2012. Denning ecology of Florida black bears in North-central Florida. Southeastern Naturalist 11(3):517-528.
- Hostetler, J. A., J. W. McCown, E. P. Garrison, A. M. Neils, M. A. Barrett, M. E. Sunquist, S. L. Simek, and M. K. Oli. 2009. Demographic consequences of anthropogenic influences; Florida black bears in north-central Florida. Biological Conservation 142:2456-2463.
- Garrison, E. P., J. W. McCown, and M. K. Oli. 2007. Reproductive ecology and cub survival of Florida black bears. Journal of Wildlife Management 71(3):720-727.