The Sweet Smell of Winter

For field biologists, winter is typically the time of year when we hunker down, pore over data, fix gear, drink lots of coffee, and dream of spring when our field season starts again. This winter is different. This year, the North Cascades Institute has traded excel spreadsheets for snowshoes and hot coffee for THE SMELLIEST SUBSTANCE ON THE PLANET! What? Let me explain:
Graduate students, staff, and volunteers from the North Cascades Institute are working in partnership with the Cascades Carnivore Connectivity Project to evaluate habitat connectivity for carnivores in the North Cascades Ecosystem (NCE). Specifically, we are spending the winter trying to obtain American marten (Martes americana) hair samples as part of a landscape genetic study.

An American marten investigates a hair snare on the flanks of Sourdough Mountain near Diablo Lake.

American martens are members of the weasel family Mustelidae and, despite the fact that they are rarely seen, are common inhabitants of Pacific Northwest alpine ecosystems. By determining the genetic structure of their populations, we can assess the connectivity of marten habitat within their range. In other words: How closely related is Marten A to Marten B? Like the rest of NCE’s native carnivores (wolverines, lynx, wolves, bears, etc.), martens must be able to roam freely through vast landscapes in order to obtain food, mates, and breeding territories. Wide-ranging mobility is also critical to ensure that populations do not become genetically isolated (population bottleneck).

The biggest barrier to gene flow for our native carnivores is human development. This study aims to look at one kind of development in particular: highways. By obtaining hair samples of American martens (and in the summer months, black bears) on the north and south sides of Highways 90, 2, and 20, researchers will be able to determine how much of an impediment these major roads pose to north-south movements of carnivores.

Graduate Students Jacob Belsher and Alex Patia celebrate a small victory for science upon finding marten hairs left behind on Sourdough Mountain.

So, where does the North Cascades Institute come in? We are installing hair snares along Highway 20 in order to non-invasively collect a few precious hairs from martens. It works like this: we ski or snowshoe into pre-determined sample sites away from the road, find what looks to be quality marten habitat, hang a ‘bole snare’ (a collection of stiff-bristled brushes under a plastic cover) and then… wait for it… spread the planet’s most horrific smelling concoction all around the snare.  Apparently, martens can’t resist the smell: dead skunk, combined with castor and muskrat musk, and (according to the manufacturer’s website) ‘special agents’, that all combine to give you the olfactory version of a heavyweight’s knockout blow. Just writing about it makes me crinkle my nose in disgust.

Graduate Student Susan Brown bravely spreads scent lure on a hair snare at Green Point on Ross Lake.

Regardless of how bad it smells, the scent lure seems to work. So far this winter, we’ve obtained marten hair samples from half of the hair snares that we’ve set up. This is great news for the research project, and potentially great news for American martens. Factors such as increased urbanization and climate change loom as very real threats to a healthy future for martens and other carnivores in the Northwest.
There is little doubt that human development and climate change will eliminate or alter habitats, potentially requiring certain animal populations to undergo major geographical shifts. The Cascades Carnivore Connectivity Project will allow scientists to evaluate current habitat connectivity and should go a long way in informing future transportation planning and carnivore conservation in the North Cascades. Hopefully that will mean a sweet smelling future for the marten.

A giant Douglas fir near North Cascades Institute’s Environmental Learning Center is a potential indicator of great marten habitat.

All photos taken by remote cameras and courtesy of Jeff Anderson and Graduate Student research team.