Apalachicola Demographics 2016-2020
FWC researchers studied bears in the Apalachicola subpopulation from 2016-2020 to monitor adult female bears and their offspring. Female survival and reproductive rates were used to estimate the annual growth rate of the subpopulation and predict subpopulation abundance from 2015 through 2025.
Researchers captured bears in Tate’s Hell State Forest, Apalachicola National Forest, and surrounding private lands and fit 47 adult females with tracking collars. Researchers tracked these animals for several years to document mortalities, annual survival rates, and reproduction. Whenever a collared female bear gave birth, biologists fitted a special, expanding collar on each of her cubs. Researchers collared and tracked 76 cubs to document mortalities and survival for cubs in their first year. See Tracking Bears to learn more about how FWC tracks and uses movement data from bears.
The probability of survival for adult females in Apalachicola was estimated to be 92% per year. Documented mortalities were caused by vehicle strikes, human-bear conflicts, and illegal kills. The probability of survival for cubs through their first year was estimated to be 67%, with most mortalities the result of predation by other bears. The average litter size was 2.2 cubs per litter and ranged from 1 – 4 cubs. Assuming that the study area and data were representative of the subpopulation, researchers calculated that the Apalachicola subpopulation was growing 12.6% each year. This growth rate means the abundance in female bears is projected to double after 6 years and may reach 3,094 female bears by 2025. Because of polygamous breeding, demographic rates of male bears do not influence the rate at which populations grow so researchers do not project the change in the abundance of males.
The completion of this study provides the FWC with important information to conserve and manage bears in the Apalachicola subpopulation. Most importantly, it shows that this subpopulation is growing and self-sustaining. Results from this study have not yet been published, but you can view the final report. Although these survival and population growth results have not yet been published, a graduate student working with the FWC has published a stable isotope analysis that used some of the data created from this project.
Projected increase of female black bear abundance, including female cubs, in the Apalachicola subpopulation of the East Panhandle BMU, growing at an annual rate of 12.6% (black line). This female portion of this subpopulation is projected to increase to 3,094 bears, including cubs, by 2025 if demographic rates are similar across the subpopulation. Grey lines show possible variations in abundance each year from 1,000 statistical simulations.