Coastal pine marten trending toward extinction on national forests

The coastal marten is at a high risk for extinction in Oregon and northern California in the next 30 years due to threats from human activities, according to a new study.

“The study, published today in the online journal PeerJ, will be available to federal and state wildlife agencies for their consideration to determine whether distinct geographic population segments of the coastal marten warrant state or federal listing as threatened or endangered, said Katie Moriarty, a certified wildlife biologist and lead co-author on the study.

Their population assessment revealed that the central Oregon population of coastal martens is likely fewer than 87 adults divided into two subpopulations separated by the Umpqua River. Using a population viability analysis, they concluded that the extinction risk for a subpopulation of 30 martens ranged from 32 percent to 99 percent.

In the short term, limiting human-caused deaths of the coastal martens would have the greatest impact on the animal’s survival, said Moriarty, who has studied the animals for several years. In the long term, the species requires more habitat, which perhaps could be accomplished by making the adjacent federal land in Siuslaw National Forest suitable for martens.”

So this isn’t just new information for use in the ESA listing process, but it also raises new questions about whether existing forest plans would provide conditions needed for viable populations.  I look forward to seeing how the Forest Service answers this question.  (And yes, the Forest Service does have the authority to limit trapping.)

20 thoughts on “Coastal pine marten trending toward extinction on national forests”

  1. When beaver were being reintroduce to NM, trapping of beaver was closed by three national forests in the state: the Lincoln, Gila and Cibola National Forests. I believe trapping as a whole is closed on all the AZ national forests.

  2. Population viability analysis (PVA) predicted the small population of 30 martens had a high probability of extinction (32-99%). I suspect the PVA was based on extrapolating recent demographic performance, including annual variation, into the future. This assumes no change in the quality of the animals, if I am correct. However, with only 30 animals, inbreeding and genetic drift will surely cause declining genetic quality and therefore declining survival and reproductive success.. If my suspicions are correct, the probability of extinction is much higher than 32-99%.

      • The paper indicated that the population estimate was not an attempt to count all the animals. Some form of “mark/recapture” estimate was used. If the assumptions were met, this method accounts for unseen animals. In any event, the population would have to be very much larger than 30 marten before my comments would be incorrect.

    • However, the black-footed ferret is recovering (500 currently) from 18 animals. Seems to me that extinction risk is highly dependent on what is done in terms of securing habitat and recovery actions including captive breeding if needed. Calculating PVA sounds a bit like calculating fire frequency and acreages without considering suppression actions and tactics. Plus there are apparently aspects of genetic variability that are more robust than commonly thought.

      • Sorry, I don’t consider 500 inbred ferrets, with serious disease problems, needing to be subsidized with “tactics” to be very desirable. It’s only the best we can do with what little was left of the species. To deny the large amount of information, experience and research on genetic issues, and merely count animals without regard to animal quality, is akin to denying climate change. Jim

        • Jim.. I don’t know that their disease problem ( mainly plague as I understand it) is related to their genetic diversity. After all , the prairie dogs get it and they are very diverse. Chestnuts were diverse and chestnut blight got them. Successful reproduction is generally thought to be the sine qua non of species health.

          • Abundant literature on the topic of effects of inbreeding shows that the most-often detected effects are lower reproductive success, poor juvenile survival and overall lowered resistance to diseases. It makes no sense to stake one’s position on the exceptions and ignore the majority of observations. I expect that ferrets, like other mammals can fall prey to many kinds of diseases, not just plague. — Island biogeography has been on the books since the 1960s. Much more has been published since. Our management agencies continue to ignore it all. Jim

            • Yes island biogeography has been on the books since the 1960’s and since then folks have found out many things about whether it is relevant to non-island populations. They have also found out many things about species that are not random mating, in other words they have behavioral tendencies such that they tend to mate with others to whom they are not related. To summarize you are correct that in general inbreeding can have negative effects in many vertebrates. The question is “how much” “inbreeding of what kind (cousins sibs parents)” and also considering species particulars.

              If signs of inbreeding depression in these martens were observed in the wild, I am not sure how increasing the habitat in itself would help. A more logical intervention would be to first increase genetic diversity by importing some genes and then increase the habitat. But then would it still be a distinct population segment if “distinction” is based on genetics?

              People had this exact problem with the Florida Panther. “The population growth, of course, was also helped by the protection of some 120,000 hectares of habitat as well as the construction of highway underpasses to cut down on road kill (10 to 20 pumas are killed every year this way, according to Onorato). But, in a sense, the original inbred population of Florida panthers is now gone, replaced by hybrid descendants with genes from Texas and Florida. Only two females from the “canonical” Florida panther population remain, and the purebred Florida males are less likely to win their battles for territory. “As you become an older fellow your chances of winning a bar fight go down,” Onorato says, also noting that Texas and Florida puma populations used to swap genes via ranges that covered the entire Southeast only a century ago.”

              So, in that case, there was also the question of whether these had been distinct populations before trapping, changes in habitat, etc.
              Low populations can be bad in terms of inbreeding depression, but if they are already that low and have inbreeding depression, then I don’t think anyone knows how much increasing habitat alone can help.

              here’s a similar story in Swedish adders. “The negative effects of inbreeding on population size are well documented in captive animals1, but there is surprisingly little evidence that genetic factors cause a decline in wild populations2,3, apart from a reported correlation of low levels of genetic variability with a high incidence of malformed or stillborn offspring4. From the point of view of conservation strategies, it is not only the effect of genetic factors on population decline that needs to be considered, but also whether introducing novel genes can prevent or reverse such a decline. Here we show that the introduction of new genes into a severely inbred and isolated population of adders (Vipera berus) halted its precipitous decline towards extinction and expanded the population dramatically.”

              • I’ve not seen any studies of outbreeding behavior and its effectiveness in small, wild populations, let alone of the species in question. As for detecting the effects of inbreeding on the qualities of animals, very often we have the poorest of data (imprecise trend data) on the quantity of animals. Even if we spend on a genetics study, it is generally on a small portion of the genome, looking at loci one at a time. We don’t know what these alleles do, but we do know that almost all traits are polygenic. In a large, functioning population with natural selection on many of the animals, we expect a large proportion of the animals to have a large proportion of the better combinations of alleles for living and reproducing efficiently in the selective environment. But with drift, the population genome becomes gradually disorganized. With that complexity of unknown relationships, and our poor population data, its all too easy to say there were no detectable effects of inbreeding, or drift if it is considered at all. And yet we look for excuses to justify our small population strategies. Jim Bailey

  3. So, what specific activities could be done, or not done, to ‘improve habitats’? Would those activities be good for other species at-risk? Would those activities be good for drought-stressed forests, at-risk to complete stand replacement? Will those activities require extreme funding mechanisms? Questions… questions… questions

  4. Sometimes it helps to read the actual study, not just the press release.

    This isolated marten population “occupies a <500 m wide band of young (i.e., <70 years old) forests growing on sand dunes along the margin of the Pacific Ocean west of Highway 101." To call the study area a "forest," is generous; it better resembles a shrub field with mature trees generally < 20 feet tall. This narrow band of wind-shaped lodgepole pine is a recent artifact of mid 20th century dune stabilization with imported European beach grass.The biggest threat to this isolated marten population may be dune restoration efforts that seek to eliminate the European beach grass that created this narrow strip of "forest" in the first instance.

  5. Two big immediate threats, according to the researchers, is trapping and roads.

    I’d imagine that road mortality is fairly difficult to reduce, but trapping mortality could be ended tomorrow.

    Right now martens can be trapped year-round without limit Oregon. I’d argue that there should be zero trapping on public lands, period.

    Regarding genetic diversity, I don’t think there’s much to worry about: so long as there are viable corridors, the martens in that area will inevitably mix up with martens from elsewhere.

  6. Where is it written that the FS must allow unfettered trapping of locally imperiled mammal populations to supply a dwindling, non-essential demand for furs. But there is plenty written, and supporting case law as well, to move the agency to stop trapping. C’mon Jerry Ingersoll, do this before you go to Alaska…

  7. Jim is correct. According to the Oregon Dunes National Recreation Area enabling legislation, the Forest Service can ban trapping in the NRA:

    The Secretary shall permit hunting, fishing, and trapping on lands and waters under his jurisdiction within the boundaries of the recreation area in accordance with applicable laws of the United States and the State of Oregon, except that the Secretary may designate zones where, and establish periods when, no hunting, fishing, or trapping shall be permitted for reasons of public safety, administration, or public use and enjoyment. Except in emergencies, any regulation of the Secretary pursuant to this section shall be put into effect only after consultation with the appropriate State fish and game department.

    No question that forestalling ESA listing furthers the “administration” of the NRA and martens contribute to the public’s use and enjoyment of the NRA, too.

  8. It does:

    In particular, FLPMA’s savings clause (43 U.S.C. § 1732(b)):
    “That nothing in this Act shall be construed as authorizing the Secretary concerned to require Federal permits to hunt and fish on public lands or on lands in the National Forest System and adjacent waters or as enlarging or diminishing the responsibility and authority of the States for management of fish and resident wildlife. However, the Secretary concerned may designate areas of public land and of lands in the National Forest System where, and establish periods when, no hunting or fishing will be permitted for reasons of public safety, administration, or compliance with provisions of applicable law. Except in emergencies, any regulations of the Secretary concerned relating to hunting and fishing pursuant to this section shall be put into effect only after consultation with the appropriate State fish and game department. Nothing in this Act shall modify or change any provision of Federal law relating to migratory birds or to endangered or threatened species.”


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