Coastlines is a new natural history column intended to raise knowledge about and awareness of native species, habitats, and human ecology in coastal Nova Scotia. A project of the Ecology Action Centre, Halifax, it focuses on Nova Scotian topics and uses as many local examples as possible.
Coastlines: Pine Marten and Old Growth Forests
By Aswea Porter*
Photograph courtesy of the Nova Scotia Department of Natural Resources
High overhead a pine marten (Martes americana) emerges sleepily from his den in a large snag. Marten are about the size of house cats and belong to a family of mammals called the mustelids; they are related to weasels, mink, otters, fisher and wolverine. Forest managers are concerned about marten for two reasons: they are the most economically important furbearers in most of Canada and they are believed to be dependent on the old growth forests that are disappearing to forest harvesting.
Old forests contain large trees and coarse woody material that is important to marten for denning and foraging. In cold weather, they tend to make their dens below the snow where they will be out of the wind. They dig into large squirrel middens or rotting stumps and logs and use the soft wood as insulation. In the spring, marten often move their dens into snags and large live trees where they are safer from predators. Fallen logs also provide good habitat for mice and voles which are favourite prey. In winter, leaning logs and branches can intercept falling snow and provide an easy access tunnel to small mammals living below.
In addition to their specific habitat needs, marten are vulnerable to habitat loss because they maintain large home ranges and have a low reproductive rate. These characteristics mean that they have a naturally low population density that can't recover quickly from a disaster.
Marten are still common in most forested regions of Canada, but they are listed as endangered in Nova Scotia and Newfoundland, probably due to habitat loss and to overtrapping in the late 19th century.
There are two populations in Nova Scotia, one in the western mainland and another in the Cape Breton highlands. The Cape Breton population is extremely small and may have been isolated from the rest of Canada since the end of the last ice age.
"Marten were reintroduced into Kejimikujik National Park in the 1980s," says Mike O'Brien, furbearer specialist with the Department of Natural Resources. "Prior to that, there had only been one confirmed occurrence of marten (in the mid 70s near Weymouth) on mainland Nova Scotia in many years. We encourage the public to report to us any sightings or other evidence of marten in their area."
The Nova Scotia American Marten Recovery Team is now drafting plans for the conservation and recovery of marten in Nova Scotia.
* Aswea Porter is a biologist who studied pine marten for her Masters degree. Coastlines is a project of the Ecology Action Centre and is supported by the Nova Scotia Habitat Conservation Fund and the Henry P. Kendall Foundation.
Further reading on the internet:
"Elusive Ghosts of the Deep Forest" by Dan Banks, Conservation, Winter 1994/85, http://www.gov.ns.ca/natr/wildlife/conserva/18-04-1.htm; Spring, 1995 http://www.gov.ns.ca/natr/wildlife/conserva/19-01-1.htm