Unsolved wildlife mysteries
Forget Bigfoot. Scientists have long been on the trail of a tiny, furry mystery in northern New England.
In late June 1898, naturalist Edward Preble set out several small mammal traps in a swampy area near the town of Carroll in New Hampshire’s White Mountains to sample the local fauna.
When he returned to inspect the traps three days later, he found numerous meadow mice, short-tailed shrews, red-backed mice, jumping mice, and one tiny, furry mystery: a small lemming mouse “hitherto unrecorded from the eastern United States.”
It turned out to be a northern bog lemming, a one-ounce rodent with a short tail, blunt nose, and scruffy brownish-gray coat that has a widespread distribution from Alaska to Labrador, but had never before been documented as far south as New Hampshire. What was it doing there? Were there more?
In his report on the find in the Proceedings of the Biological Society of Washington, Preble left the mystery to posterity: “Whether this species is a wanderer from the Hudsonian Zone on the neighboring mountains…or whether it is a regular inhabitant of the Canadian Zone throughout this region is an interesting question to be solved by future investigations.”
More than a century later, the investigation is ongoing.
“It’s been a question mark for decades,” said Steve Fuller, who now coordinates studies of at-risk species conservation for the U.S. Fish and Wildlife Service, but encountered the northern bog lemming in the early 2000s while working on a profile of the species for New Hampshire’s Wildlife Action Plan. Encountered on paper, that is. Few people — at least, few people who knew what they were looking at — have actually seen one.
At the time, conventional wisdom considered the northern bog lemming a lost cause in northern New England because there were so few confirmed occurrences.
But scientists didn’t give up on the elusive rodent. This year the U.S. Fish and Wildlife Service partnered with New Hampshire Fish and Game, the Maine Department of Inland Fisheries and Wildlife, and the U.S. Forest Service to organize search parties for the northern bog lemming in New Hampshire and Maine.
On the case
The search is informed by modern investigative techniques. Service spatial analyst Renee Farnsworth developed a habitat model that cues into moist, mossy areas at high elevations in New Hampshire and Maine. Local experts reviewed the map, and helped narrow down to the most likely lemming sites.
Before the search got underway, fellowship biologist Allison Earle developed a standard survey protocol to make sure everybody who conducted surveys was following the same playbook.
With these tools, members of the Service’s Science Rapid Response Team are now searching the places where the species is most likely to be hiding. That team comprises fellowship biologists, like Earle, who specialize in helping to solve wildlife mysteries: they work with staff and partners to develop a coordinated, robust approach to filling data gaps for at-risk or poorly understood species, like the Bethany Beach firefly, the White Mountain arctic, and the northern bog lemming.
Critters you’ve never heard of and you’ll probably never see, often because they live in places that aren’t easy to get to.
Each survey outing for northern bog lemming involves a long drive to a trailhead, and a long hike to a boggy area.
“We’re focusing on sites at around 2,000 feet in elevation,” said fellowship biologist Kathryn Nolan. “Sometimes a site is right off a trail, but sometimes you need to bushwhack to get there.”
The journey is only half the battle. “The survey sites are saturated, often within beaver complexes,” said fellowship biologist Ryan Bell. “It’s cold, it’s wet, and you’re crawling around on your hands and knees digging through shrubs, trying to find small mammal burrows.”
But they’re not looking for northern bog lemmings in those burrows. They’re looking for lemming poop.
Poop, or “scat” to a wildlife biologist, contains DNA that can tell you the species and the sex of the animal that left it behind — if you collect it fresh and preserve it before DNA degrades beyond recognition.
This season, the Science Rapid Response Team has collected more than 1,000 pellets from about 20 sites (and counting), which may or may not have been left by northern bog lemmings. That’s for Zach Olson to determine.
An associate professor of animal behavior at the University of New England in Biddeford, Maine, Olson developed the technology to identify northern bog lemming biomarkers in scat. Every couple of weeks, one of the fellows delivers a box of vials full of pellets preserved in buffer solution to Olson for testing.
Even that process is labor intensive. Olson outlined the steps in an email: “There’s lab work to extract the DNA and target our specific gene fragment, and then we submit the samples to a sequencing facility, where there could be a two-month turnaround depending on how packed their machines are. Finally, we do bioinformatics on the boatload of sequencing data that comes back from the sequencing facility to assign species IDs to the samples we submitted.”
You don’t need to understand what any of that means to get that it’s complicated.
The intensity of the effort reflects the stakes. The northern bog lemming is considered a species of concern in New Hampshire, a threatened species in Maine, and a science-needs species by the Service — meaning we need more science to make an informed decision about its status.
Pending the DNA-test results, the surveys may help fill in one of the most glaring information gaps: where the species occurs, or does not occur, in Maine and New Hampshire.
“One of the strategic challenges we face with so many poorly studied species is simply knowing where they are,” said Fuller. “We are getting more efficient at using technology and good hard field work to get the job done, and that’s the first step to conserving them.”
Missing link
In the meantime, we need to sift through the information we already have. During a fellowship with the Service’s Maine Field Office this summer, Mael Glon worked on multiple sections of the northern bog lemming Species Status Assessment — an analysis that synthesizes the best available information on a species to inform an Endangered Species Act decision.
He focused on sorting out the taxonomy — how the species is classified. “There were all of these different subspecies that had been identified, but there was a lot of redundancy and misclassification resulting from a lack of regular correspondence among people who were collecting 100 years or more ago,” he said.
But many other questions remain: what it eats, when it breeds, how big a litter it has, how far it disperses.
Scientists need to know all these details about where and how the northern bog lemming lives to determine whether or not it needs help. Climate change adds to the urgency because of the potential to make the cool, wet habitat where we think it lives warmer and dryer.
There’s also the existential — or maybe, eco-stential — question that the northern bog lemming represents. If this tiny, furry mystery depends on a niche habitat that’s hard to find in northern New England, what other mysteries share its home?
Over the summer, Glon had the opportunity to see the habitat first hand when he joined endangered species biologist Mark McCollough from the Service’s Maine Field Office for a northern bog lemming survey expedition in northern Maine.
“I was blown away by how interesting this ecosystem is — it’s just a floating expanse of moss,” he said. “It really shows the need for broad scale, strategic conservation. Because you can protect ‘X’ number of acres, but if you miss these little pockets of diversity, you are missing unique species.”
The Rapid Response Team has spent weeks this fall investigating little boggy pockets within rugged northern landscapes dominated by spruce and moose on behalf of other unique species that could be there. While collecting pellets, they’re also documenting habitat conditions and threats — very carefully.
“Part of the challenge of working in these vulnerable ecosystems is making sure we don’t disturb them,” said fellowship biologist Kevin Reifenberg. That means after often grueling hikes to reach these remote bogs, they have to tread lightly and focus intently. “It’s important to document as much as we can while we’re in this habitat to help understand what the rare species that live here need,” he explained.
Rare species we are trying to find, and rare species we aren’t even looking for — yet.
The northern bog lemming is a tiny, furry reminder that the natural world is full of unsolved mysteries.
The effort to conserve at-risk wildlife and recover listed species is led by the Service and state wildlife agencies in partnership with other government agencies, private landowners, conservation groups, tribes, businesses, utilities, and others. It has drawn support for its use of incentives and flexibilities to conserve rare wildlife, reduce regulations, and keep working lands working.
