The American Marten in the Tahoe Basin

By: Jill Olson

This American Marten was kind enough to stop and pose for a rare photo.

The Nevada Department of Wildlife (NDOW) was pretty surprised to get such a great picture of this American marten, as it stopped momentarily from its scramble up the tree to pose for a photo. The heat/motion sensor camera that took the picture was setup as part of an ongoing study NDOW has been conducting in the Lake Tahoe basin to identify the numbers and species of wildlife currently present in the area. As reclusive as the marten is, it’s highly likely it would be far out of sight had it known that the motion sensor camera was placed in its path.

“You’re about as likely to see an American marten as you are a mountain lion,” said Pete Bradley, Nevada Department of Wildlife eastern region biologist. That means you’d be pretty lucky to sneak a peak at the weasel-related furbearer, which is about the size of a small house cat.

Why are the chances so slim? Just like the earlier mentioned feline, the American marten is extremely nocturnal, meaning it’s awake and most active during the nighttime hours. Add to that its small size, its preference to live alone and avoid social interaction, and its tree-dwelling tendencies and you get a hard to find mammal.

In fact, NDOW western region biologist Shawn Espinosa, who conducted the Tahoe basin furbearer study and is constantly hiking, snowshoeing, and surveying the area, would be thrilled to see a marten firsthand. “When you’re in the area constantly and never see one, catching the marten in action on camera is the next best thing.” Espinosa said.

Not to say the marten is a complete hermit. Quite the opposite is true if you consider its home range may span 2 to 10 square miles where the marten travels in search of food – and that’s quite a trek for a two pound critter. Marten travel alone, with the exception of mother and young, and do not allow other marten of the same sex in their territory. According to Espinosa, current surveys may lead to further investigation to determine more definite home ranges and denning sites of marten in Nevada.

This marten attempt to get an easy meal, and is out on a rarely seen daytime adventure.

What are marten searching for as they trek their home ranges for a scrumptious meal? Marten are carnivores, or meat-eaters, that hunt mice, voles, squirrels, chipmunks, and birds like the blue grouse (though they are not much bigger than their winged prey). Although they hunt mainly on the ground, they are fast enough to catch squirrels in the forest canopy. They also eat insects, earthworms, eggs, seeds, and berries to supplement their meal in the summertime.

American marten are part of the weasel family, and one of the few of that family that climb trees (fishers, long-tailed weasels and short-tailed weasels will climb trees as well). Other members of the weasel family found in Nevada include mink, river otter and badger. Marten are found in forested areas throughout North America, including the Sierra Nevada, and span from northern New Mexico to the northern limit of trees in arctic Alaska and Canada. They are also sporadically present in the Great Lakes region.

Marten are native to Nevada and NDOW’s current study is helping biologists expand their knowledge about small and medium furbearers in the Tahoe basin. “These studies serve as a baseline for future habitat improvement projects and conservation plans,” Espinosa said when explaining the importance of such surveys.

“The presence of furbearers like the marten in the Tahoe basin is an indication of overall forest health. Many animals are dependent upon old growth forests for habitat. Old growth forests make up only 5-10% of the forest in the Tahoe basin, so we want to perpetuate and expand upon that old growth, to help sustain a healthy balance.” Espinosa explained. “Often, we also can determine just how adaptive some animals are to new conditions, like second growth forests, or human presence.”

While Espinosa’s study proves that marten endure in western Nevada, their current and historic numbers elsewhere in the state is uncertain.

“There is recent evidence of marten remaining in the Jarbidge, Ruby and Snake Mountain ranges, yet no living marten have been confirmed in northeastern Nevada,” Bradley said of the eastern region.

Currently, Nevada is one of six states in which marten may not be legally taken at any time or in any area.

Marten are curious creatures, and though considered arboreal, or tree dwelling, (they spend much of their time scampering from branch to branch on paws with retractile claws) marten make their dens in downfall, hollow logs, rock crevices, or abandoned burrows lined with leaves, moss or other vegetation. Such a den makes for a nice new home when a female marten bears her litter of kits, which usually consists of three to four babies. The male is not involved in rearing the kits, and is back to its solitary habits once again after mating in the summertime.

Bradley explained that females have a unique trait called delayed implantation where the gestation period, or the amount of time between mating and the birth of the litter, is 275 days, yet the fertilized egg is not implanted into the uterus until about one or two months before the kits are born. This allows for mating in the summer and giving birth in the spring, thereby allowing them to focus on survival in winter.

The young marten will grow up to look similar to mom and dad - typically golden to dark brown in color with a yellowish throat and chest and a lighter underbody. They have black markings at the tip of their tails and at their feet, and their feet can get very large in proportion to their body. Their large feet are useful in the winter snow, acting, in essence, like a pair of snowshoes as they pursue their prey. Marten weigh an average of two pounds and are about six inches tall. Females are (21-23) inches long and males are (24-27) inches long, including their long bushy tail that is about one third of their size.

So, next time you are out hiking in the forest, keep your eyes open. You may be as lucky as NDOW (or at least our cameras were) to get a rare wildlife viewing opportunity and witness an American marten.