Center for Conservation Biology

Monitoring fisher populations

USFS Pacific SW Research Station

Kings River, Sierra Nevada Mountains, CA

handler and dog on a log

Bud Marks and CK9 FrehleyBrad Nicols


Every spring and fall, beginning in 2006, Conservation Canines has sent two teams down to the Sierra Nevada Mountains in California, to find fisher scat for the USFS. Fisher are a large member of the weasel family that have been trapped out of many parts of their historic range. Today, the Sierras represent the southern-most portion of the fisher’s range. In addition to live-capture and telemetry work conducted by the USFS, the data we collect is vital in shaping our understanding of fisher biology, particularly in relation to wildfires.

CK9s on the study

Did you know?

  • Fisher scats come in many shapes and sizes.
  • They can be composed almost entirely of wasp exoskeletons or manzanita berries or hair.
  • They can be large or small.
  • This high degree of variability makes the dog’s nose even more important for correct identification.


  • Thompson, C.M., J.A. Royle, and J.D. Garner. 2012. A framework for inference about carnivore density from unstructured spatial sampling of scat using detector dogs. Journal of Wildlife Management 76: 863-871.
  • Thompson, C.M., K. Purcell, J. Garner, R. Green. 2010. 2010 Kings River Fisher Progress Report. USDA Forest Service.

Additional link

US Forest Service

Additional photos