Agile, elusive and undeniably adorable, the pine marten (Martes martes) is a member of the Mustelidae family — a group that includes other mammals such as mink, weasels, otters, polecats and badgers. Pine martens, as well as almost all of the other six types of martens around the globe, usually live deep in coniferous and deciduous forests, jumping from branch to branch and tunneling through the snow. Pine martens are found across Europe and even in parts of the Middle East. In Britain, the population has experienced a sharp decline, causing them to be a rare and endangered species, but luckily, they're making a comeback.
Pine martens, as well as other species of marten, are small and slender creatures comparable in size to a domestic cat. They grow to be 25 to 31 inches (68 to 81 centimeters) long, including their bushy tail, and only weigh between 2 and 5 pounds (0.9 and 2.2 kilograms). Their silky brown fur, small, rounded ears, big paws and yellowish-tan bib give them their lovable look. But don't let their cuteness and size fool you — their paws contain sharp, partially retractable claws, and they're known to be aggressive. Those powerful claws, along with the martens' speed and ability to climb trees, allow them to easily turn small mammals into their next meal. They even have the rare level of speed needed to catch a squirrel, making them an important part of balancing the ecosystem. Overall, martens eat a varied diet; they catch rabbits, mice and small birds, and will forage for berries, worms, insects and eggs. They live for an average of about eight years in the wild.
Are Pine Martens the Same as American Martens?
Cody Aylward, a Ph.D. candidate in the department of wildlife, fish and conservation biology at the University of California Davis, studies martens and shares in an email interview that, while they look extremely similar, there's strong scientific consensus that the pine marten, often referred to as the European pine marten, and the American marten (Martes americana) are distinct species. He explains that, while there are seven species of marten in the world, American martens occur throughout most of the forested regions in Canada and Alaska, as well as a handful of states in the lower 48. But in North America, specifically south and west of the Rocky Mountains, you'll also find the Pacific marten. While morphologically similar to the American and pine marten, Aylward says science has also debated whether the Pacific marten is a subspecies or a separate species altogether.
Where Do Pine Martens Live?
Chances are high that you've never seen a pine marten — or any marten. Aylward explains, "They prefer to be deep in the forest, far from roads or fields, in areas that receive significant snowfall. Their habitat preferences align pretty well with things that make terrain difficult for humans to access. They are also most active in the very early morning or late evening, so fewer people are out in the wilderness at the times of day that martens are most likely to be visible."
One great testament to their elusiveness comes from Aylward's research on American martens, which, in their skittishness, mimic the pine marten. "Martens were reintroduced to the Green Mountain National Forest in southern Vermont in 1989. A few years after the reintroduction, a follow-up study concluded that the reintroduction was unsuccessful. There were no reports of martens in the area for the next twenty years. Then in 2010, a few martens were captured in fisher traps in southern Vermont and our genetic work showed that these animals were, in fact, descendants of the 1989 reintroduction. So, for over twenty years martens lived in the Green Mountain National Forest without any confirmed records of their existence."
Martens don't create their own dens; rather they use hollow trees, rocks, birds' nests or even the nooks and crannies in the roof of a home. Pine martens are solitary but come together for short periods to mate. Females generally have a litter of around three babies once a year.
Are Pine Martens Endangered?
Across most of Europe, the pine marten population is stable. But in Britain the numbers are still dangerously low, though legal protection and conservation are helping populations to make a comeback. Overall, the number of American martens has decreased, but they are not yet considered endangered. What's the main cause of the decline? Human behavior.
Historically, martens were trapped for their fur (think mink coat), but there's currently appropriate regulation that makes trapping a minimal threat. The real problems are deforestation and climate change, says Aylward. He explains further, "... even changes as subtle as constructing a dirt road through the forest can negatively affect martens by making these remote areas more accessible to larger carnivores such as foxes and coyotes."
Climate change is specifically reducing the snowpack that martens rely on. "Snow is important because martens have specific adaptations that give them an advantage in snow relative to other carnivores. They have wide feet compared to their body weight, which act like snowshoes and allow them to travel more efficiently in deep snow. They are also capable of traveling and hunting in the "subnivean zone" (aka, underneath the snow). Deep snow helps martens by limiting the densities of larger carnivores such as fishers, foxes and coyotes," Aylward says.
Conservation Efforts Are Showing Results
Forest conservation is undoubtedly crucial, but there are additional tools that can be used. Aylward shares that reintroduction is a popular and impactful conservation step. "A reintroduction is when animals are captured from an existing population and released into an area where the species has been extirpated (locally extinct). But there's even yet another conservation tool that's growing in popularity — identifying and preserving habitat 'corridors.' Habitat corridors are areas of forested habitat that occur between these small and isolated populations; even if the corridors themselves cannot support a marten population permanently, they can increase the chances of successful migration between two isolated populations, which increases gene flow and reduces the chances of inbreeding depression," explains Aylward.
Much of his research has aimed to identify the best corridors for martens in New England. And there's good news in Britain: Research published June 14, 2020 in the Journal of Applied Ecology suggests that the increase in numbers of pine marten in Northern Ireland is helping to limit the numbers of invasive grey squirrels, in turn aiding the recovery of native red squirrels.
Can You Have a Pine Marten as a Pet?
Even if you're still 'pining' over their cute faces in the photos, bringing a marten home as a pet isn't an option. But by supporting conservation efforts around the globe, you can help martens thrive and ensure nature's delicate balancing act continues for generations to come.