Developing close-kin mark-recapture methods to monitor Michigan black bear populations
October 2021 - September 2023
- Michigan Department of Natural Resources
Michigan Department of Natural Resources (DNR) and other state management agencies currently uses statistical catch-at-age analysis (SCAA) to monitor trends in bear populations and impacts of harvest. However, SCAA is highly sensitive to initial values of abundance and requires periodic independent estimates of abundance using mark-recapture (MR) to calibrate SCAA model estimates. The marking technique previously implemented (tetracycline) is no longer available to resource managers and alternative methods of MR (e.g., barbed wire corrals with individual identification from hair using DNA, or physical capture and release) requires extensive sampling and field effort, demanding additional financial and logistical resources. Thus, there is a need to develop novel methods to estimate trends in black bear abundance and impacts of harvest without requiring additional independent field sampling. Close-kin mark-recapture (CKMR) extends the concept of recapture probability of a marked individual to the probability of capturing a closely related individual. The primary objective of this project is to develop CKMR models specific to black bear populations in Michigan, assess sensitivity and accuracy, and make recommendations on most effective approach. The results of this project will be used by the Michigan DNR and other state agencies to refine and improve harvest-based monitoring of black bears.