You may know that Alberta is home to multiple carnivores, but how much do you know about the American Marten? Often a lesser-known mesocarnivore, now’s your chance to learn more about this must-see mustelid!
Who Are They?
This individual has a very light underside marking. Photo credit: Jacob W. Frank, Public domain, via Wikimedia Commons.
The American marten (Martes americana), also known as the pine marten, is a member of the Mustelidae family. During the active period of the 18th century fur trade, the marten was also known as the American sable. This agile, arboreal (tree-dwelling) weasel has a slender body ending with a long, fluffy tail, and a fox-like face with prominent ears. The Mustelid family is diverse, containing carnivores both large and small, this includes wolverines, badgers, otters, skunks, and weasels. The marten’s fur is dark brown, and they have a distinct colour patch from chin to belly; this patch ranges from cream white to yellows and oranges. Martens range in size from 0.6 to 1.3 kilograms in weight and 49 to 65 centimetres in length. On average, males are fifteen percent larger than their female counterparts.
Martens are often sighted in trees. Photo credit: Maria Mejia, at Lu Carbyn Nature Sanctuary.
Where do they live?
In the past, martens were inhabitants of forest regions in mountain ranges as far south as West Virginia, New Mexico and central California, into the northern United States and as far up as Alaska and northern Canada. Deforestation and extensive fur trapping for their luxurious, soft pelt has extirpated them from the southern range. Extirpation refers to ‘local extinction’, when a species no longer exists within a specific geographical range. In addition to the human interference of hunting decreasing populations, martens have been observed to avoid burned or cutover areas. American martens can be found in mature coniferous forests; their range coincides closely with the distribution of montane and boreal forests. Montane forests are defined as ecosystems located in high elevations, above 1,000 metres. Ideal habitat includes mature coniferous forests, with dead trunks, branches and leaves.
What do they eat?
The ground litter provides shelter for voles and other rodents, the marten’s main food source. Voles make up the majority of the marten’s diet, while primarily carnivorous, they are also opportunistically omnivorous. These determined little predators are also known to hunt squirrels, snowshoe hares, pika, bird eggs, insects, carrion, and will occasionally forage berries or other vegetation. Day or night, you can find the American marten scaling trees on the hunt for its next meal. Unlike its counterparts the fisher and the mink, the marten stashes what it cannot finish eating.
Life cycle
A marten kit. Photo credit: Colorado State University Libraries, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons.
Outside of breeding in July, or mothers raising young, martens are solitary. Mating occurs in July, however, young are not born until March or April. This delay occurs due to a natural process called delayed implantation. The female marten is able to retain a fertilized embryo in a state of arrested development or stasis for a number of months, the majority of the growth occurs in the last month of gestation (pregnancy). Martens are born weighing around 34 grams, and are blind and hairless. Putting birth weight into context, the average apricot weighs 35 grams. Denning occurs in hollow logs or trees, sheltered from the elements and dens are lined with soft vegetation like grasses, mosses and leaves. In the wild, martens live 8 to 10 years and in captivity, they live 15 to 17 years.
Mastering Mustelid ID
Image credits: Mink (far left) tsaiproject from Canada, CC BY 2.0 https://creativecommons.org/licenses/by/2.0, via Wikimedia Commons | Fisher (middle image) Pacific Southwest Region USFWS from Sacramento, US, Public domain, via Wikimedia Commons | Marten (far right) lwolfartist, CC BY 2.0 https://creativecommons.org/licenses/by/2.0, via Wikimedia Commons
The American marten has two lookalikes, the American mink (leftmost image) and the fisher (middle image). The marten is pictured furthest to the right. The fisher’s tail is twice as long and it has no white throat patch, with retractable claws. A fisher’s fur has a grey ‘frosted tip’ appearance to it. The mink has shorter ears, and is more aquatic than its counterparts. Shorter legs mean it's not adept at climbing trees, and its tail is sleek rather than fluffy.
Martens as Indicator Species
Martens are environmental indicators, which refers to a species that reflects how well an ecosystem is doing. They have been observed returning to improved burn or cutover areas, indicating a healing ecosystem where a loss of trees has occurred. When hunting protections were put into place in the state of New York, the rapidly decreasing marten population re-established itself successfully in the Adirondacks.
This highlights the importance of conserving existing habitat to preserve biodiversity. Though the marten is just one species impacted by deforestation and habitat loss, their presence in an ecosystem confirms that conditions are acceptable enough for the species they rely on to live: trees, rodents, insects, and many more.
You can help with the conservation of habitat like the marten’s preferred mature Boreal forest by supporting local nature conservation organizations like EALT. Though donations are an important part of our operations, support can also look like joining a volunteer event, or even simply telling a friend or sharing our posts on social media.
Thank you to Mackenzie Anderson for writing this blog.