Back in the lab, we extract DNA from the hair. Using specific genetic markers, we can then identify individuals and determine the sex of each bear. When we detect the same individual at multiple sites or on different occasions, we can consider that a re-capture of the bear.  Knowing when and where we detected each bear allows us to then estimate the density of black bears in different areas of the state. These densities then allow us to estimate the population size of black bears in Massachusetts.


Photo credits: C. Centeno, E. Hollers, T. Kristensen