Jumping Slugs! And Other Unique Animals of Olympic National Park

Weighing less than a pound, Olympic yellow-pine chipmunks are one of the smallest mammals found in the park. They have brownish fur with white underbellies, and dark and light stripes running from their backs across their face to the tips of their nose. You will more often hear them than see them in the subalpine zone, where forest blends into meadow. Feeding mainly on seeds, nuts, berries, insects and sometimes fungi, they are able to store a relatively large amount of food in their large cheek pouches.

Found in mountain meadows above 4000 feet, Olympic Marmots are incredibly social and playful creatures. They are about the size of a housecat with a long bushy tail, and eat plants such as heather, lupine, grasses, sedges, and mosses. When they emerge from hibernation in May or June, their pelts are yellow or tan, which will soon shift to more brownish, and finally almost black in the fall. During hibernation, their heart rates can drop to 3-4 beats per minute! One of the greatest threats to the Olympic Marmot, whose numbers declined in the 1990’s and early 2000’s, is predation by non-native coyotes. Many experts believe that climate change is a large contributing factor as decreasing snowpack in alpine meadows, the habitat of marmots, makes a more desirable habitat for coyotes. In 2010 the park initiated a monitoring program that enables volunteers to record the presence or absence of marmots in many meadows throughout the park.

In 2009 the Olympic Marmot became a state symbol as Washington’s official state endemic mammal

thanks to the efforts of 4th and 5th grade students at Seattle’s Wedgwood Elementary School.

Similar to other short-tailed weasel species found in the northern hemisphere, the Olympic short-tailed weasel is long, slender, fast despite its short legs, and strong despite its size. Weasels are carnivorous, feeding mainly on small rodents like chipmunks and squirrels, but able to take mammals larger than themselves such as snowshoe hares. The distinguishing feature of the Olympic short-tailed weasel is that it keeps its brownish coat, with yellowish underbelly, year round; whereas other weasel species turn white in preparation for the winter. They inhabit lowland forests up to the subalpine zone and make their homes in the burrows of small rodents that became their prey.

This salamander is found commonly at the edges of cool, clear, streams in the old growth forests of Olympic National Park. They have medium to dark brown skin, a yellow underbelly, and small dark spots.

Interestingly, they have reduced lungs and breathe mostly through their skin!

They will flip over, exposing their yellow undersides when disturbed in an attempt to startle potential predators. Habitat loss and logging are the major threats to the Olympic torrent salamander, especially since their habitat is extremely small and limited; any loss of habitat could be detrimental.

One of seven species of the genus of air breathing land slugs, this slug is found on the undersides of bark on the forest floor. Slugs play an important role in the ecosystem as recyclers of organic material including living and decomposing plant foliage. Unlike snails, which hide their internal organs in their shells, and other slugs, which keep them in a cavity in their foot, jumping slugs are unique in that they have a soft “hump” on their back where their organs are carried.

 They also have a small shell, which resembles a fingernail, that serves no known purpose. Perhaps the most intriguing behavior of these jumping slugs is their defense mechanism, which gives them their name. When threatened by carnivorous slugs, salamanders, or other predators, they “jump” by coiling up and straightening out repeatedly in rapid succession. This dislocates their body from whatever surface they are on, effectively breaking their “slime trail” and escaping from threats.