(CN) — The coastal marten, a West Coast relative to minks and weasels, will be listed as a threatened species by the U.S. Fish and Wildlife Service due to habitat loss.
On Wednesday, the U.S. Fish and Wildlife Service announced the coastal population of the Pacific marten would be listed as a threatened species in a final decision filed with the Federal Register.
“The coastal marten faces a variety of threats including loss of habitat, threats from wildfire, and increased predation risk,” the service said in its final rule. “These risks play a large role in the resiliency and future viability of the coastal marten.”
Often confused for river otters, the Pacific marten makes its home in old-growth forest or areas with dense shrub coverage along the Pacific Coast in Northern California and central Oregon. They’re also voracious carnivores, eating voles, mice, birds and fish.
Until 1995, the Humboldt marten population was thought to be extinct due to logging practices, forest management and trapping.
According to the federal agency’s final rule there are four pockets of martens along the Pacific Coast in groups fewer than 100 across Oregon and California, with diminishing populations in the northern and southern ends of the mammal’s historical range.
In California, the marten can be found in Humboldt, Del Norte and Siskiyou counties and in Oregon they’re found in several counties including Curry, Josephine and Lincoln.
In its 102-page final rule, Fish and Wildlife said the two biggest threats to the coastal marten is “a decrease in connectivity between populations” and “habitat conversion” into an environment that is more suitable for predators and competitors, which could increase “coastal marten injury, mortality, or predation.”
Martens prefer old-growth forests, but forest fires and intensive logging in the last 40 years undoes the characteristics that allow them to escape from predators like bobcats.
“Bobcats prefer regenerating harvested stands less than 30 years old, and are nearly absent from older forests, the preferred habitat used by coastal marten,” the agency found.
Old-growth forest used to cover more than 75% of coastal California where the martens were once found and anywhere from 25% to 85% on the Oregon coast.
In terms of connectivity, marten groups in Oregon do not have any functional connectivity to other populations, according to Fish and Wildlife. The California martens would not be able to repopulate areas in Oregon should a “catastrophic event” wipe out the Oregon martens.
In other words, the California groups have some connectivity to one another, but not to Oregon.
Car traffic is also a concern in the preservation overview for the marten, according to Fish and Wildlife, with 19 confirmed deaths reported since 1980.
“We expect that some unknown amount of coastal marten roadkill goes undetected, so this is likely an underestimate of the number of coastal martens killed by cars,” the agency wrote.
Illegal cannabis grows on public, tribal and private forest lands also lead to deadly exposure from insecticides. In fact, the agency reported that 85% of the carcasses of a similar carnivore called the fisher showed traces of rodenticides and for 13% rodenticide exposure was the direct cause of death.
The findings in Fish and Widlife’s latest report are a far cry from a report it issued several years ago.
The Center for Biological Diversity and Environmental Protection Information Center petitioned to list the marten as threatened in 2010, but after four years of study Fish and Wildlife determined neither the species as a whole nor the tiny California subpopulation qualified for protection because the marten was not at risk of extinction in all or most of its range.
The same environmental advocacy groups challenged the study’s findings as not supported by the best available science. In 2017, a federal judge ordered the federal agency to reevaluate its decision.
Fish and Wildlife’s listing of the marten as threatened becomes official in 30 days.
Also Wednesday, the agency also listed the eastern black rail — an elusive mouse-sized bird sometimes referred to as the “feathered mouse” — as endangered in South Carolina.
But the agency proposed downgrading the red-cockaded woodpecker from endangered to threatened status as the species has seen an improvement in its numbers. The agency will seek public comment before making a final decision.