Report: Fishers on the Decline in California
Posted on July 9, 2011
A new study has found that the density of fishers - a house-cat sized member of the weasel family - decreased by 73% in Northwestern California between 1998 and 2005. The Hoopa Valley Tribe cooperated with the Wildlife Conservation Society and the University of Massachusett on the study. Two fisher kits are being weighed by researchers on California's Hoopa Valley Indian Reservation in the photo above.
The scientists speculate that changes in prey habitat, disease, and increases in predation (particularly from bobcats) may be responsible for the decline in fishers. The researchers say additional efforts are needed to determine trends in fisher populations and expand monitoring to other regions. Data was collected using a mark-resight method, where fishers were captured, ear-tagged and subsequently photographed at remote camera stations.
WCS Conservation Biologist Sean Matthews says, "It is critical to understand the status of a population when making decisions about species conservation. Our study further demonstrates the importance in monitoring populations of imperiled species and the limitations of some methods in detecting large changes in population size."
The study appears in the June edition of the online journal, The Wildlife Society Bulletin. Co-authors on the study include Sean M. Matthews of WCS, J. Mark Higley and J. Scott Yaeger of the Wildlife Department of Hoopa Tribal Forestry, and Todd K. Fuller of the University of Massachusetts Department of Environmental Conservation.