RED CLIFF, Wis. — American marten have been discovered on Manitou and Stockton islands in the Apostle Islands National Lakeshore for the first time in more than 40 years, park officials say.
An American marten was verified on Manitou Island in 2014 when a visitor took a photo of it running between his legs.
This past spring, when researchers began checking thousands of images from the 30 trail cameras they had placed on Stockton Island last winter, they were surprised to see a few images of American marten, a small mammal that’s on Wisconsin’s state endangered species list.
That’s the first documented sighting of marten on Stockton since 1969, according to Apostle Islands National Lakeshore officials.
The recent findings also have led to many additional discoveries, including visitor reports or photos from three other islands and the rediscovery of photos taken in 2010 of a marten on Stockton Island.
“It’s very cool,” said Julie Van Stappen, chief of planning and resource management at Apostle Islands National Lakeshore. “It appears marten are doing pretty well on the islands. Everywhere we’re looking, we’re finding signs of marten, although the only place they’re verified 100 percent is on Manitou and Stockton.”
In the past several months, the park subsequently has received unconfirmed reports or photos of animals that are thought to be marten on other islands, including Otter, Rocky, Sand and Oak, say park officials and Erik Olson, assistant professor of natural resources at Northland College in Ashland.
Olson has been conducting scat surveys on many of the islands, and those samples are currently undergoing genetic analysis. That analysis has the potential to determine whether the marten in the Apostles are from a reintroduction in the 1950s, from remnant marten populations on the islands, from animals that dispersed from marten reintroductions elsewhere in Wisconsin or from Minnesota or Michigan.
Biologists with the Red Cliff Band of Lake Superior Chippewa near Bayfield also have documented marten on the reservation since 2010, said Jonathan Gilbert, wildlife section leader for the Great Lakes Indian Fish and Wildlife Commission at Odanah.
Finding their way back
American marten were native to Wisconsin but were nearly extirpated in the early 20th century due to loss of habitat and over-trapping, said Neil Howk, assistant chief of interpretation and education at the national lakeshore, headquartered in Bayfield. Following multiple reintroduction attempts in the state over the past four decades, there are recovering populations of marten in the Chequamegon-Nicolet National Forest, according to researchers at the University of Wisconsin-Madison.
“It’s part of our native ecosystem that’s been missing (in the Apostle Islands). Now, it’s seemingly slowly finding its way into re-establishing itself,” Howk said.
Nobody knows for sure how the marten are reaching the islands, but presumably they would have to cross over the ice in winter or swim in the summer. It’s 5 miles from the mainland at Red Cliff to Stockton Island, and 6 miles to Manitou.
The trail cameras were placed on Stockton Island as part of a carnivore research project led by the University of Wisconsin.
“It’s pretty fascinating we’re finding American martens on the Apostle Islands that may have been undetected for some time now,” Northland’s Olson said.
The origin of the recently documented marten also is unknown.
“The question is where did they come from?” said Gilbert of the Great Lakes Indian Fish and Wildlife Commission.
A few marten were reintroduced on 10,000-acre Stockton Island in 1953 and again in 1956, but the last sighting of one was in 1969.
“One hypothesis is that martens have survived on Stockton Island since the release in 1953, and we have just not seen them,” Gilbert said. “Another hypothesis is that the martens in Red Cliff and the islands came from the releases which occurred from 2008-2010 in the Chequamegon-Nicolet National Forest, about 60 miles south of Red Cliff. The third hypothesis is that martens were never extirpated from the islands. We do not know which of these is correct.”
The DNA research now being conducted should be able link present-day marten on the islands to one of those source populations, Olson said. That research is a joint project of Northland College, the National Park Service and the University of Wisconsin-Madison.
Meanwhile, trail-camera work will be conducted on more islands in the Apostles to see if marten can be verified on those islands.
“It’s wild,” Olson said. “We’re waiting on further verification, but this will be interesting to see. There appears to be a decent chance of a population of marten on a fair number of these islands.”
A Wisconsin marten timeline
Early 20th century — Marten extirpated from Wisconsin
1953 and 1956 — Marten reintroduced into Wisconsin at Stockton Island by Wisconsin Conservation Department
1969 — Last confirmed sighting of marten on Stockton Island. Marten were thought to have died out.
1975-1983 — Marten reintroduced into Chequamegon-Nicolet National Forest near Clam Lake
1987-1990 — More marten reintroduced into Chequamegon-Nicolet National Forest
2008-2010 — More marten reintroduced into Chequamegon-Nicolet National Forest
2010 — Red Cliff Band of Lake Superior Chippewa confirms sighting of marten on reservation with trail-camera image; Apostle Islands National Lakeshore (in 2015) confirms identity of a marten in a photo taken on Stockton Island in 2010.
2014 — Apostle Islands National Lakeshore confirms sighting of marten on Manitou Island through photo provided by a visitor
2015 — Apostle Islands National Lakeshore confirms sightings of marten on Stockton Island with trail cameras
2015 — Scat collection, visitor observations and photos identify a number of additional islands that may hold marten. Researchers await verification from genetic analysis or trail-camera surveys.
Source: Apostle Islands National Lakeshore, Great Lakes Indian Fish and Wildlife Commission, University of Wisconsin-Madison