Tag: Kentucky Falls

Signs of Life

Looking for wildlife signs along a trail is a great way to stay curious while hiking.  

Lines of inquiry open up like, “Hey, what are all those holes in that tree over there?”  “Look! I think I see a nest. What is it made out of? Is it active or abandoned?” “An animal track! What animal came through here? How recently did it pass by? Where is it headed?” And of course, “Why?” 

Burrows, holes, and dens are especially interesting to think about.  Questions arise, like, “What made that?” “Where does it go?” “Does the organism that made it live there?” “Does it allow guests?” “What lives there now?”

So last weekend, after a long drive on forest service roads, I was excited to see a sign posted warning hikers about trail instability due to Mountain Beaver tunnels and dens at the Kentucky Falls Trailhead near Mapleton, OR.  I had never heard of a Mountain Beaver (What the heck?) or seen (at least not with any idea of what I was looking at) its telltale signs.  I had a lot of questions. But first, off to the hunt- a.k.a hike! 

The Hike

Canopies and Cascades

The Kentucky Falls trail is a GORGEOUS hiking adventure with towering trees and waterfalls. Douglas-fir and Western Hemlock reach skyward all along the trail as you wind your way down to the first gushing waterfall- Upper Kentucky Falls.  Moss covered rocks, sword fern, and plenty of other native herbs and forbs carpet the forest floor. The hike continues downward, over a bridge, and past the trail junction for the North Fork Smith River Trail and ends at the base of twin 100-foot waterfalls- Lower Kentucky Falls.  

Curiouser and Curiouser

There were many interesting observations to make while hiking on this trail. The power and volume of the waterfalls, for example, raises questions about the size of the watershed and source of the water.  Is it purely rainfed? I wonder how different it will look later in the year when things dry up.

The structure of the forest also struck me. The Douglas-fir and western hemlock were tall and stately, but interspersed between them I saw dozens of short, decaying western red cedar snags.  There has to be a story there too…

Down the Mountain Beaver Hole…

BUT I was on a mission…  I needed to find signs of Mountain Beaver (Aplodontia rufa)!  Where are the tunnels?  

It didn’t take long, before I found what I was looking for. 

The trail was saturated with several openings that looked like they would accommodate a small mammal, perhaps the size of a small rabbit or large gopher.  It appeared the tunnels crisscrossed under the trail at unequal intervals, as there were holes heading into the embankment below and the trail above.   

At one point on the trail, it looked like an old tunnel system may have caved in leaving a large depression in the middle of the trail (I wish I had measured it!- darn!).  Perhaps one of the tunnels had been large enough to act as a den, or there were too many tunnels crisscrossing that they all collapsed. Whatever had happened, it looked like an old occurrence, as nature was reclaiming the space. 

As I reached the bridge crossing and started down toward lower Kentucky Falls, I didn’t notice the tunnel system anymore.  Either I was too captivated by the rest of the surroundings to notice any tunnel openings, or they just weren’t in that area.  

In any event, by the time I was back to the car and heading home, I had more questions than answers. I didn’t even know the basics, like “What the heck is a mountain beaver?”  I was going to have to do some research to find out. 

Mountain Beaver Basics

First things first, the name- Mountain Beaver- is a misnomer.  Mountain beavers are not closely related to Oregon’s State Animal, the North American Beaver.  They are more related to squirrels, if you need something to compare to. They are not really considered alpine animals either, as they prefer lower elevations in the Coast range and western Cascades, and have never been spotted above treeline. 

Second, there is not a lot of information out there about the mountain beaver.  For example, if you look up mountain beaver on the Oregon Department of Fish & Wildlife’s website you get a very brief description emphasizing the fact that it has a short nearly “invisible” tail. The blurb explains that the mountain beaver is a muskrat-like rodent with five toes and dark brown fur with white markings near its ears. Oh, and that it is found in the Oregon Coast Range. Literally, that is about it. Though the Washington Department of Fish & Wildlife was more helpful at providing details on the mountain beaver, in general, I found mountain beaver information rather limited and mostly focused on dealing with them as a pest species to timber operations. 

Digging Deeper

However, “digging deep” into researching mountain beavers, I was able to make some sense of what I had seen and thought about while on the trail.  

According to WDFW’s website, Mountain beaver tunnel openings are typically 6 to 8 inches in diameter, and tunnels can go as deep as 10 feet underground. Their tunnel systems are composed of several chambers that they use for different purposes like food storage, nesting, or a latrine. Mountain beaver are solitary mammals, as well as territorial. A single mountain beaver may occupy an area of 2 acres or more.

Despite my lack of x-ray vision, with opening after opening found along the trail, as well as the possible den collapse mentioned earlier (at least that is my hypothesis), there was plenty of evidence to support the idea that I was seeing an extensive mountain beaver tunnel system. In addition, the lack of tunnels I found as I moved further down the trail may be explained by the mountain beaver’s territorial nature- it is likely I had hit the boundary of a mountain beaver’s territory.

Habitat Needs

Like all of us, mountain beaver have needs. They need a lot of water to drink- requiring a ⅓ of their body weight in water daily- and vegetation, like ferns and tree seedlings, to eat.  (They also feed on their own excrement, but that is another story…)

Fortunately, water was very accessible on the trail; several very small streams ran across it.

Food was equally available. And there were many signs along the trail that our rodent friend was partaking. You see, mountain beaver will clip food off from the base of plants- eating from the bottom up.  Piles of clipped plants can sometimes be found temporarily stored outside a tunnel opening. Luckily, I was able to capture photo evidence of this phenomenon (see the picture above) – though admittedly by accident.

With a nearby water source and ample food, one thing is for sure, the Kentucky Falls trail provides perfect mountain beaver habitat!

Old is the New Young

Another fun fact about mountain beaver is they are old!  On a geological scale they are ancient for a mammal. They are the only surviving members of the Aplodontia genus of rodents that has been around 35 million years!  

However, despite their age, recent research done by Samantha Hopkins, from the University of Oregon, brings into question the long held belief that mountain beaver are primitive – existing as living fossils. Using fossil evidence, Hopkins found that “since they emerged as a species”, mountain beaver have gone through A LOT of changes- “their bodies have grown from the size of chipmunks to that of ground squirrels and then to marmots and muskrats.” Really, very little of what we now see in modern mountain beavers is primitive. 

Clearly, there is more science to be done if we are to understand and appreciate this elusive rodent.

So, next time you are in the Coast Range of Oregon or the foothills of the Cascade, look around!  Though you probably won’t see one, mountain beaver signs are hard to miss… when you know what you are looking for.  

Credits

1. “Mountain beaver | Oregon Department of Fish & Wildlife.” https://myodfw.com/wildlife-viewing/species/mountain-beaver. Accessed 9 Feb. 2020.
2. “Mountain beaver | Oregon Department of Fish & Wildlife.” https://myodfw.com/wildlife-viewing/species/mountain-beaver. Accessed 9 Feb. 2020.
3. “Researcher helps fill in the family tree of the shy mountain ….” 8 Jan. 2020, https://around.uoregon.edu/content/researcher-helps-fill-family-tree-shy-mountain-beaver. Accessed 9 Feb. 2020.