Coastal Marten Project

Coastal martens, a distinct population segment of the Pacific marten and analogous to the Humboldt marten, are a squirrel-sized weasel that historically occurred from the northern border of Oregon to Sonoma County in California. The contemporary distribution of coastal martens appears to be substantially reduced and facing multiple threats. Population declines were so severe that coastal martens were considered extremely rare or extirpated until the mid-1990’s when martens were detected by researchers in northwestern California. Consequently, the coastal marten is federally listed as threatened, is listed as state endangered in California, and is a species of Greatest Conservation Need in Oregon and California.

Additional survey efforts were conducted throughout the 2010’s, expanding the understanding of contemporary marten distribution to include four geographically isolated populations. Despite advancements in our understanding of Humboldt marten distribution in northern California and southern Oregon, many critical data gaps remain.

We are collaborating with state and federal agencies, tribal communities, private-industry partners, and other academic researchers to better define the geographic extent and connectivity of these putative marten populations. Documenting underlying variation in habitat associations, demography, and genetic composition of coastal martens within populations will facilitate assessments of resiliency, redundancy, and representation that are needed to understand the vulnerability of martens to compounding threats of climate change, altered disturbance regimes, and habitat fragmentation and to implement effective recovery actions.