Using track-plate footprints in fisher mark recapture population estimation

Obtaining accurate estimates of fisher (Martes pennanti) population abundance is challenging to resource management agencies given the large home ranges and low densities at which fisher occur. Current methods for estimating population abundance are expensive in terms of equipment required and hours worked indicating a need for a less labor and equipment intensive method. Track-plate footprinting is a method of individually identifying fisher by the papillae patterns found on the metacarpal pad. We evaluated the technique of track-plate footprinting as a mark-recapture method to estimate population abundance of fisher in the Ottawa National Forest of Michigan's Upper Peninsula. We placed covered track-plates using copy toner and a medium of contact paper as a method of obtaining footprints of fisher for individual identification. Over 1548 trap-nights we identified 24 prints from nine different fisher with four individuals being recaptured. Program Mark produced a population estimate of 13 animals with a 95 confidence interval of 8-20 animals. Our study shows that track-plate footprinting is a viable method for estimating population abundance of fisher under natural conditions.