Hair Ice is Doped for Beauty

Late one frosty morning, I paused my walk to admire ice crystals that had grown from a small branch lying on the ground. Delicate and lacy to the extreme, the ice had a silky and well-kempt appearance. The formation was gorgeous.

silky ice, parted neatly in curls, growing out of dead wood

This was my first glimpse of hair ice, a phenomenon that originates in a surprising way.

If you live in a temperate climate that experiences hard frosts, you might be familiar needle ice. Even though it forms on frosty nights, this type of ice isn’t frost because it doesn’t condense out of the atmosphere. According Dr. James Carter of Illinois State University, it forms instead from in water in soil through ice segregation, a process when “above freezing and below freezing temperatures are juxtaposed. At the Earth’s surface this is most common in fall at night as the air cools to below freezing while the land surface stays relatively warm.” As ice forms on the soil surface, liquid water is pulled up from below through capillary action and freezes to the existing ice. This forces the ice to grow away from the freezing surface. The process stops when the temperature becomes cold enough to freeze everything up, the temperature rises above the freezing point of water and everything melts, or the soil surface becomes too dry.

Hair ice however, forms under even more specific, and perhaps unusual, circumstances. Like needle ice in soil, hair ice needs air temperatures just below freezing and a water saturated substrate. Unlike needle ice though, hair ice forms only on wood, specifically the dead and bark-free wood of broadleaf trees. Why only on dead wood?

silky looking ice growing out of dead woodsilky looking ice growing out of dead woodSee more photos of hair ice on iNaturalist

In 2015, researchers from Germany and Switzerland published a very interesting (and highly readable for a scientific paper) study titled, “Evidence for the Biological Shaping of Hair Ice.” Through repeated observations and laboratory experiments, they confirmed that the biological action of a winter-active fungus, Exidiopsis effuse, is required to enable the growth of hair ice.

Looking at the cross section of a small branch, wood rays radiate from the center of a branch like spokes on a bicycle wheel. From these rays, hair ice threads emerge and grow perpendicularly from the wood surface. The thickness of individual hair ice stalks corresponds to the diameter of the wood ray channels. Perhaps for the first time in my life, I could visualize the true scale of these cellular channels.

But this doesn’t explain how the ice maintains its shape. Threads of hair ice are extremely thin, sometimes .02 millimeters in diameter or smaller. Yet, they can grow to be 20 centimeters long (that’s 1,000 times longer than it’s thickness!) and maintain their shape for days. Normally, ice this fine couldn’t retain its shape for so long. It would recrystallize into larger crystals quickly at temperatures near freezing.

While the chemical process that preserves its fine and delicate structure is not fully understood, it seems that the ice, according to the 2015 study’s authors, is “doped” into maintaining its shape by fungi. Samples of melted hair ice contain lignin, tannins, and other compounds. Lignin cannot be digested by animals, only by fungus and some bacteria. It’s presence in the water, therefore indicates fungal activity. (We can thank fungi that forested habitats aren’t buried in dead trees.) The lignin and tannins might act as a crystallization surface for the ice and the fungi might help to initially shape the ice as it forms at the surface of the wood rays.

When researchers applied fungicide or hot water (90-95˚C) the hair ice wood for several minutes, hair ice formation was suppressed for many days. Instead of hair ice, an simple ice crust formed on the wood. This indicates that hair ice formation is somehow catalyzed by fungal activity and that high temperatures inhibit the activity of Exidiopsis effusa.

Since I first observed it, air temperatures have been too warm in my neck of the woods for hair ice to reappear. Given its ephemeral nature and remarkable delicacy, I’ll be sure to search for it once the temperature drops again. If I find it, I’ll surely be astonished by ice that was—in a sense—doped by a magic mushroom.

Winter Frogs

At Oregon’s South Beach State Park last month, I heard a chorus of frogs hidden among the grassy dunes. Following the calls, I found a few dozen Pacific tree frogs (Pseudacris regilla) in a shallow ephemeral pool where the males were calling loudly in an effort to attract females. When I stooped low to record a video, they were so loud I should’ve been wearing earplugs.

A few of the males got lucky too.

frogs in amplexus

bow-chicka-wow-wow

These frogs can be active all year when conditions are right. My night at the state park coincided with a stretch of very warm weather that coaxed the frogs out of their torpor. (The daytime high in Newport was 62˚F, a new record for the date.)

Winter weather in coastal Oregon and northern California is often wet and chilly, but low elevation areas rarely experience freezing temperatures. For someone who grew up in Pennsylvania and spent several winters on the Alaska Peninsula, “normal” winter still includes ice and snow, so the climate along Pacific Ocean remains somewhat novel. Seeing frogs in January, especially, enhanced that feeling.

A January Bear

It was late January, but I enjoyed nearly perfect hiking weather in Big Bend National Park. The sky was clear, the wind was calm, and the temperatures hovered in the hiking Goldilocks range (for me, that’s the low 60˚s F). I had spotted a few piles of bear scat earlier that day, but all were dry and desiccated. Then in the late afternoon, I found one particularly fresh pile of crap.

This scat was soft and pliable and hadn’t been exposed to the dry desert air for very long. (I poked it with a stick to gain a very scientific measure of its age.) Was there a bear nearby? I hoped to find out.

The previous day, I stopped in the Chisos Basin Visitor Center to purchase a book to help me search for the park’s endemic oaks. A map on the visitor center wall was marked with sticky notes identifying when and where people had spotted black bears. At least a dozen had been seen over the past two weeks. I made a mental note to watch carefully for bear sign. Maybe, just maybe, I would be lucky enough to see one for myself.

Mountain rising above pine and juniper forest

The pinyon-oak-juniper habitat near Emory Peak (center) is preferred habitat for Big Bend’s black bears.

Although I spent considerable time searching for the endemic oaks (and found at least a couple, plus some species rarely found in the U.S.), bears were never far from my mind. Backcountry campsites all had bear-resistant food storage boxes, and signs clearly informed people that bears will take your unattended pack.

metal sign. Text says, "Bear Country Do Not Leave Back Packs Unattended"

Occasionally, I’d find old piles of bear scat or a marking tree.

scratch marks on bark of tree

Black bears used this Arizona cypress (Hesperocyparis arizonica) near Boot Spring as a marking tree.

No long after I photographed the marking tree, I stumbled on the aforementioned scat. Its freshness caught my attention, but it wasn’t steaming so I couldn’t be sure if a bear was close or not. I only knew it was there earlier in the day. As I proceeded up the trail, motivated to pick up my pace and return to the campground before dark, two hikers traveling in the opposite direction told me they had just seen a bear not far from the trail. This was their first wild black bear sighting, and they spoke excitedly about their experience. I thanked them for the info and continued on, now even more alert.

The hikers said the bear was near a switchback in the trail, not far from a backcountry campsite. I slowed my pace as I approached that location, not wanting to startle the animal. A moment later, through some thick vegetation, I heard cracking branches and there it was—a black bear.

black bear ears seen through thick vegetation

My soon-to-be award winning wildlife photo of a black bear in Big Bend National Park. Move over Tom Mangelsen.

What would a bear be doing out in January? Since bears are omnivorous and eat a wide variety of food, their scat reveals a world of information about where they’ve been and what they’ve been up to. The fresh bear scat I found 10 minutes before, like the older scat on the trails, was filled with fragments of pinyon nuts and shells. Pine nuts are exceptionally nutritious, containing almost 700 calories per 100 grams. The pinyons pines in the Chisos Mountains seemed to have produced a sizable cone crop in 2016, one which helped sustain the bears into mid winter.

pile of black bear scat in grass

Pinyon pine nut shells and fragments fill this fresh pile of bear scat. I found this scat just moments before seeing an active bear.

The density of the shrubs made it difficult for me to se exactly what the actual bear was doing, but it appeared to have its nose to the ground and it wasn’t moving far. Perhaps it was still feeding on pine nuts.

pine cones on the ground

These Mexican pinyon pine (Pinus cembroides) cones still hold their fatty nuts.

Black bears in the Chisos Mountains rely heavily on habitats with pinyon, oak, juniper, and grassy talus slopes, although male bears will make more frequent use of low elevation areas. Even so, this was January 26. Shouldn’t the bear be inside a den?

Black bears in more northernly locations hibernate well before January. However, bears in Big Bend don’t typically enter their dens until late January or February, and when they do many don’t seem to fully enter hibernation. Male bears, especially, are more likely to remain active. Pregnant females in Big Bend, like other bear populations in North America, have the longest average denning period, beginning in mid to late December and ending in late April.

This winter activity isn’t unique to Big Bend’s bears. Black bears in Florida have similar winter dormancy patterns. Mild weather and the prospect of food, especially, can keep bears active for longer time spans. After all, bears are avoiding winter famine more than winter weather when they hibernate. The bear I saw probably wasn’t doing anything abnormal for a Big Bend black bear. It was just another bear doing bear things like eating and shitting in the woods.

The Other Wanderer

Most mammals aren’t keen to reveal themselves to people, which I understand. I don’t want to be around people much of the time either. Unless I’m very lucky or very observant (sometimes it’s both), I typically don’t see the more elusive animals that inhabit the North Cascades ecosystem. Winter, however, provides an opportunity to see the animals without actually seeing them.

In winter, animal tracks in snow reveal stories I could never read otherwise. Without tracks, I would be oblivious to the presence of most animals, so on every trip outside I look for them. On a recent ski journey, I found some tracks I did not expect to see.

The day was comfortable (35˚F/2˚C) and sunny. The snow was reasonable firm. I parked Large Marge at the end of plowed section of road and skied up valley. Skiing wasn’t fast, but it wasn’t a slog either. With long sleeves, I felt overdressed in bright sun, so I paused frequently to cool down and enjoy the view.

River running through snowy forest.

Pillows of snow sat on rocks in Stehekin River downstream of High Bridge in Lake Chelan National Recreation Area.

I found High Bridge, which is the boundary between the national recreation area and the national park, buried under several feet of snow.

cabin in deep snow

The NPS cabin at High Bridge was mostly buried by snow.

outhouse buried in snow

Good thing I didn’t have to use a toilet, because this outhouse at High Bridge wasn’t accessible.

Up to this point, I had seen or heard little evidence of animals. Douglas squirrels were active because I found bracts from Douglas-fir cones scattered under a couple of trees. Red-breasted nuthatches occasionally called from the tree tops (this species is one of the most common in the Stehekin Valley in the winter; at least one of the most vocal.) There was no sign of large or even medium sized mammals.

The snowy road offered a convenient path so I followed it up valley, especially since the avalanche forecast was high and I didn’t want to risk getting caught in any slide. About a mile from High Bridge, I noticed a set of faint, but fairly large tracks in the snow.

wolverine tracks in snow next to ski pole

The set of tracks I found. What animal made them?

The tracks were fairly large, although I lacked measuring tape to get accurate measurements. My first thought was “mountain lion,” but then logic started to creep in (thanks Spock). Mountain lions eat many animals, but prey probably isn’t abundant enough in the mid to upper Stehekin River valley at this time of the year to sustain a mountain lion. I saw no deer tracks, even though deer are common in the lower valley now. Other characteristics of the tracks eliminated mountain lion as the source.

  • The tracks weren’t the right size or shape.
  • Their pattern, or gait, was a 3 x 4 lope.
  • Claws marks registered with almost every track.
  • The tracks rarely broke through the snow’s surface crust. This animal, despite its size, could float on the snow.
  • Fur marks often registered around the toes.
  • Most importantly, this animal had five toes.

This was a wolverine.

wolverine track in snow next to basket on bottom of ski pole.

This fairly distinct wolverine track clearly shows the animal’s five toes. The basket on the ski pole is 7.5 x 7 cm.

The track pattern indicated it was walking in some places, but loping most of the time.

Wolverine tracks in snow.

Wolverine tracks in snow. Each set of three, starting from the bottom, represents a one lope made by the animal.

Wolverines are the largest members of the weasel family and occupy huge home ranges. The tracks were fresh, their crispness suggested they were made early in the morning or overnight. If they had been made the day before, the warm sun would’ve obscured some of their finer details.

What might it eat in this habitat? Perhaps one of the squirrels or hares out and about.

scales from Douglas-fir cone scattered on snow

A Douglas squirrel had recently torn apart a Douglas-fir cone on this pile of snow.

Snowshoe hare tracks in snow next to ski

Snowshoe hares were also moving about the forest.

At Tumwater Bridge, the wolverine continued across right next to tracks of a marten, a smaller more arboreal member of the weasel family.

wolverine tracks (bottom) next to smaller marten tracks. Tip of ski at bottom center.

Wolverine tracks (bottom) run parallel to marten tracks.

The day was waning at this point, so I turned around and left the wolverine and its tracks behind.

Last year, a large male was trapped and radio collared at Easy Pass by the U.S. Forest Service and Washington Department of Fish and Wildlife. This is almost 20 kilometers due north of the tracks I found. Could it have been the same one?

Maybe, maybe not. Wolverines occupy huge territories and are rare in this area. I was lucky to stumble upon this set of tracks before they disappeared in overnight rain. That day, I was probably the only human in the south unit of North Cascades National Park, but I certainly wasn’t the only mammal prone to wander.

Read more about on the wolverine’s status in Washington.

More Snow? Yes, More Snow.

Yesterday, I wrote about a ski trip in Stehekin Valley’s ample snow. Since I took that trip a few days ago, more snow has fallen. A lot more.

This was the scene I woke to yesterday.

Deep snow outside of home

And, snow was slowly enveloping the neighbor’s house.

deep snow covering home

This is nothing abnormal for the region, and in many way’s it is expected. In winter, the jet stream over Alaska and Canada shifts south over the Pacific Ocean. Air masses traveling across the Pacific at this time of the year are “immodestly moistened,” as Daniel Matthews describes in Cascade-Olympic Natural History, bringing heavy precipitation to Washington, Oregon and California. The Cascade Mountains and Sierra Nevada are effective moisture traps for these storms. When storms encounter the mountains, the air rises and cools causing it to precipitate its moisture. The Stehekin Valley in Lake Chelan National Recreation lies east of the Cascade Crest, so the area experiences drier weather than the wetter Skagit River valley to the west. However, the valley is not far enough east to experience the Cascades’ full rain shadow, hence the ample snowfall recently.

In my estimation, at least three feet (approximately 50-100 cm) of snow has accumulated over the past five days, much of it falling in the last 24 hours. Higher elevations certainly gained more. I was curious to know the exact snow depth near my house, which lies at a modest 1100 feet (335 meters). After the snowfall abated yesterday afternoon I got out the snow shovel prepared to dig in.

I chose to measure the snow out in a small meadow away from the influence of trees, but getting there took some effort. The first few feet of snow was very soft. The base to stand on, if you could call it that, was well under the surface.

After floundering my way into the meadow, I started digging…

snow shovel in deep snow

and digging…

snow shovel in deep snow

…and digging and digging until I reached the soil.

snow shovel in deep snow

The pit was over 65 inches (166 cm) deep!

Snow shovel in deep snow next to measuring tape. Tape is 65 inches long.

measuring tape in snow. Numbers at top of snow level read 65 inches or 166 centimeters.

Long time residents describe winters with lots of snow and occasional rain too. Rain compacts the snow, increasing its density but decreasing its depth. This winter, I’m told, is a bit of an exception with lots of snow, but without temperatures warm enough for the occasional rain storm.

Winter snowfall is essential to the well being of millions of people across the West, especially farmers who cannot depend on summer rain to sustain crops. Snowmelt in rivers quenches the thirst of residents in Los Angeles, Las Vegas, Phoenix, Salt Lake City, and many, many other places. It’s a reservoir, slowly releasing its water in spring and summer when it is needed most.

Climate models indicate changing weather patterns will come to the West as temperatures rise. The North Cascades region won’t be without snow, but changes will be felt, and in a lot of ways the region is already experiencing them. More rain will fall and less snow will collect on the mountains. At first this may seem insignificant. However, this will change the timing and duration of peak stream flows. Currently, stream discharges peak in the spring and early summer when snowmelt is heaviest. The pattern seems to be shifting toward more frequent peak flows in spring and fall. Rain on snow events can cause heavy flooding, damaging roads and homes. (Stehekin River has experienced three 100 year floods since 1995.) Warmer springs temperatures melt snow faster, affecting sensitive habitats like montane wetlands, places that harbor sensitive species like the Cascades frog. Soils dry faster without snow too, increasing the risk of wildfire.

Snow is often viewed as an annoyance or danger, delaying and restricting travel, but it is a key component of ecosystems where it occurs. Snow on mountains is a water tower, one we can’t afford to lose. (It’s also a lot of fun to play in.)

Person standing in deep snow pit. Pit is 65 inches deep.

(I’m really not that short, am I?)

Let It Snow

After three months of aimless wandering, I’m back in Stehekin and, well, there’s a lot of snow.

snow covered trees under overcast sky

Stehekin and Lake Chelan National Recreation Area lie just east of the Cascade Crest, but well within the Cascade Mountains. When moisture-laden winter storms move east from the Pacific Ocean over the Cascades, they dump prodigious amounts of snow. Stehekin averages 120 inches of snowfall each winter. In 1996, 298 inches of snow fell, almost 25 feet. Although I don’t know how much snow has fallen so far this winter, it’s not a trivial amount.

Earlier this week, I was eager to explore the snow-shrouded landscape, so I strapped some skis on to Large Marge and headed out.

No, not that Large Marge. This Large Marge, my fat tire bike.

fat tire bike with skis strapped horizontally on it

Two tools of winter exploration: Large Marge and cross-country skis.

I cycled on an icy, freshly plowed road to the Stehekin landing strip to ski the Stehekin River Trail, which parallels the Stehekin River downstream to Lake Chelan. It’s a pleasant hike in summer when the trail is easy to follow. The snow changed this familiar trail greatly. Where thick snow obscured the exact route I had to watch gaps in the vegetation carefully to stay on the trail.

deep snow and trees

Where’s the trail?

I needn’t worry about getting lost though. The trail is bordered by Stehekin River one on side and 8,000 ft. tall mountains on the other. I only had to stay in between. The trail has no significant elevation gain, but traverses some tricky spots for someone like me who sucks at skiing.

small open water channel next to steep slope

Caption: Short, steep bluffs next to the river’s side channels were difficult to negotiate on narrow skis. I often side-stepped up and down these places instead of risking a fall into open water.

The scenery was worth the effort, however.

River and snow covered trees

Stehekin River.

Animal tracking is always on my mind when there’s snow. The snow records much about an animal’s behavior as it moves through the landscape. The deep snow of the Cascade Mountains present a very difficult challenge for large and medium-sized animals, however. If you’re not a small mammal that can live under the snow or in the trees, then you either hibernate or abandon the high country and migrate to areas with less snow pack.

Partly because of lots of fresh snow and partly because most animals are either under the snow or in a different area altogether I didn’t see many animal tracks. A few Douglas squirrels were out and barked a warning when I skied under their tree, but there were few fresh signs of large animals on the upper half of the trail in the deep, soft snow.

Where the trail passed under a thick canopy of Douglas-fir and grand fir, I found the skiing easier. Tall conifers intercept a lot snow before it falls to the ground. When it does fall, it often does in large clumps that compact quickly on the ground. In these areas, deer and elk often “yard-up” to avoid getting mired in the deeper snow of open areas. Might I find deer and elk sign here?

ski tracks through forest

I encountered little fresh powder where conifer trees grew thickly. These areas are often preferred places for deer and elk to travel and rest. In open areas, my feet plowed through at least 20 centimeters of newly fallen snow, making travel more difficult.

On the river’s floodplain, under a tall Douglas-fir, I found a depression where barely an inch of snow covered the ground. Elk tracks radiated away from it, and a few pellets of elk scat lay within it. Evidently, this was a frequently used resting place for at least one elk.

depression in snow from resting elk

An elk had repeatedly used this bed to rest. For scale, the Douglas-fir trunk is larger than one meter in diameter.

Shortly afterward, my approach spooked an elk away from the fallen branch it was feeding on.

conifer twig clipped by browsing elk

Twigs nibbled by members of the deer family have ragged edges. An elk recently nipped the end of this Douglas-fir twig.

I only caught a glimpse of the elk, but it was a bull with sizable antlers. Carrying antlers into late winter seems counterintuitive and a waste of calories. Those antlers weigh a lot, and it can’t be cheap, energetically speaking, to keep them on your head. Shouldn’t this animal have shed its antlers by now?

Unlike deer and moose, who shed their antlers in early winter, elk often keep their antlers until spring. Different selection pressures may have controlled the timing of antler shedding. Antlers can be used for defense, but they are most often used to maintain dominance. This is especially important during the fall rut. For elk, antlers may be needed to help maintain dominance in the winter as well when access to food is limited. Deer and moose tend to overwinter in small groups or solo where competition with fellow moose or deer for browse may not be an issue. Elk, in contrast, overwinter in larger herds where antlers may be needed to maintain dominance; not for access to females of course, but for access to food.

That elk appeared to be alone, but as I approached the end of the trail near the lake, I skied past two deer, at least one of which was a buck, sans antlers.

mule deer looking at camera through fallen trees

The Stehekin River Trail ends at Weaver Point where the National Park Service maintains a boat-in/hike-in campground. Snow reduced visibility in the dim afternoon light, but the scene was gorgeous.

snow covered mud flats and steep mountainside

Lake Chelan seen from Weaver Point.

Seeing the land blanketed in a meter of snow gives it a very different appearance. It was almost as if I was exploring the area for the first time. In a way, I was. Winter in the Stehekin Valley is wholly different than summer.