A cute forest predator on the brink of extinction showed up for the cameras

Scientists at Oregon State University (OSU) have updated data on the coastal marten, a stealthy predator about the size of a ferret, also called the Humboldt marten.

The species suffered a sharp decline in numbers in the 20th century due to human activities and is still vulnerable: today it is represented by a few small, isolated populations in coastal forests of northern California and southern Oregon.

The fieldwork took three months and took place in 2022 in an area of about 150 square miles east of the town of Klamath (northern California). To avoid disturbing the animals, the team used non-invasive methods: camera traps and "hair traps" (devices on which an animal leaves hairs as it passes by). Genetic analyses were then carried out on these samples and were able to distinguish dozens of individuals.

Observations showed that the animals were found throughout the study area, but most often in two types of locations:

• on high forested ridges where snow cover is stable in winter;
• and below, in ravines and near watercourses in coastal forests.

The authors emphasise that these results are important for the species' conservation and forest management: coastal martens tend to gravitate to areas with "old growth" forest features - dense canopy, large trees and lots of woody debris that help with both hunting and hiding.

The federal conservation agenda also provides additional context. According to the U.S. Fish and Wildlife Service, the coastal (Humboldt) marten has lost more than 90 percent of its historic range and was listed as threatened under the Endangered Species Act (ESA) in 2020. Key threats include habitat loss, effects of historical trapping, large fires, and the impact of certain vegetation management practices.