A western conservation group wants Endangered Species protection for flying squirrels on Southeast Alaska’s Prince of Wales Island. The group says logging on Tongass National Forest land is a threat to the animal’s survival.
Wild Earth Guardians offices are in Colorado, Arizona and New Mexico but it’s focused one of its latest efforts on flying squirrels in Southeast Alaska. The group is petitioning the U.S. Fish and Wildlife Service to list the population on Prince of Wales Island as endangered or threatened. Guardians wildlife program director Mark Salvo says the small mammal is one of the most imperiled in the west.
“Our purpose and our goal is to protect all imperiled species in the western United States,” Salvo says. “This is a species that is threatened by current and future land uses. And a listing under the endangered species act would help to direct and guide management of its habitat to ensure that the flying squirrel persists in the future.”
The Prince of Wales population is a subspecies of Northern flying squirrels, and has also been found on smaller islands around POW. The creatures are nocturnal and they feed on truffles and blueberries. They move through the forest by gliding from tree top to tree top, up to 250 feet in one jump. Salvo says logging is a threat to the animal’s habitat.
“The latest planning documents leave much of the island open to logging, setting aside only some small old growth reserves of mostly low volume, isolated forested areas,” he says. “So this leads us to believe that this sensitive species, already identified by science as imperiled will become further endangered by logging in the near future.”
The petition acknowledges not much research has been done on squirrel population trends but says the animals are “probably experiencing significant declines due to widespread destruction and fragmentation of its habitat.” The group also highlights logging that’s occurred at two narrow points of the island at Neck Lake and Sulzer Portage and says large open spaces make it difficult for squirrels to move safely between areas of old growth forest, their primary habitat.
Scientists have studied squirrel numbers on portions of the island but don’t have an overall population estimate, or know about population trends. The U.S. Forest Service’s Brian Logan, forest wildlife biologist for the Tongass, says it’s difficult to count squirrel numbers.
“What we typically do in situations where we have a species that’s hard to sample like that, we will sample limited areas and then extrapolate from that. We haven’t specifically done that for POW flying squirrels,” Logan says. “We have ongoing studies that look at the response of the understory in previously harvested timber stands. And as part of that we are counting squirrels and looking at the responses of some of their foraging substrates like truffles.”
Logan says the Forest Service’s conservation strategy for the Tongass protects habitat for squirrels and other wildlife. That strategy centers around a network of reserves of old-growth forest, along with standards for development that is permitted on other land.
“The design of the conservation strategy, as part of that design we looked at is it capable of maintaining viable populations across the forest and Prince of Wales flying squirrels is one of those species that we’ve considered,” he says. “So we do monitor the conservation strategy and its effectiveness. And at this point in time we feel it’s a valid strategy and we’re confident in the protections it affords all species across the Tongass, including the POW flying squirrel.”
Forest Service surveys on Prince of Wales and Mitkof islands have found some of the highest flying squirrel densities in North America. The forest service’s 2008 management plan for the Tongass noted that timber harvest “can adversely affect squirrel populations…if clear cut size is too large or if some scattered tall conifers in large cuts are not retained as cover and for travel across the open spaces.” The agency’s research shows the importance of upland old-growth forests to the animals, but also suggests the squirrels can survive and breed in mixed forest around muskegs.
More recent research has looked at the animal’s habitat and diet. Liz Flaherty, with the University of Wyoming, studied how flying squirrels move across the forest after a timber harvest.
“That part of my research showed that flying squirrels are not the most efficient runners,” says Flaherty, “which is really not surprising since they do have the skin that attaches their wrist and their ankles. And so long distance dispersal having to run would require a lot of energy by the flying squirrels if they just had to focus on running and not gliding.”
Flaherty also did a diet study and the effects of timber harvest on the truffles, a kind of fungus eaten by squirrels.
“There’s still truffles that are available in the clear cuts up to about three years post harvest,” she says. “But the truffles which were in most of the diets of the flying squirrels that we surveyed really are not a reliable food source until as long as 40 or 50 years or maybe more following timber harvest. That being said, there’s always ways that wildlife can overcome these challenges.”
The state of Alaska’s Endangered Species Act coordinator Doug Vincent Lang says the state has no specific concerns about the viability of flying squirrels at this time. And Chris Maisch, state forester says the Forest Service’s management plan for the Tongass has adequate protections to ensure both a viable timber industry and wildlife populations.
The Wild Earth Guardian’s petition could lead to a status review for squirrels. Bruce Woods a spokesman for the Fish and Wildlife Service says the next step will be analyzing the petition and determining if it includes enough information for a government review.
“Before we can do that we’ve gotta have funding allocated for that because we’re not legally allowed to do anything that we don’t have funding approved for,” Woods says. “We are in the process of talking to our headquarters in Washington about funding for our listing program. When and if the funds are allocated we will begin to analyze the petition.”
Woods says that review would determine what information is available on the subspecies.
“Apparently some threats have been identified in the past including habitat fragmentation but in terms of recent numbers on population and indications on population trends I am not aware of that information although it may be out there and frankly that’s one of the things that the search during the petition analysis would determine.”
The petition review process, if it is funded, can take a couple years. Fish and Wildlife this summer also received a petition to list the Alexander Archipelago wolf.