Beaver notes

A spell of warm temperatures before the winter solstice let beavers continue stocking their caches with branches. Although adult beavers can live off stored fat for quite a while, young ones are still growing and need to eat. So a beaver family caches a nice pile of fresh branches not far from their lodge entrance. Here are excerpts from a Dredge Lake area trailcam video of a beaver systematically de-branching a little tree and toting away the branches for its cache. I noticed two uncommon things that this beaver did; readers might like to check the video and see if they can spot these two things. (**My two choices are given at the end of this essay; no peeking!).

The solstice came and went, but it will be a while before we can really sense the lengthening days. Meanwhile, a couple of days after the solstice, I wandered over to the Dredge Creek area. The recent deep freeze had covered the ponds with strong ice, shutting down beaver activity for a while. A snowfall had brightened the landscape and registered movements of small critters. I found a trail left by a shrew, making short bounds under a bush. Another shrew had trotted across an open space and under a log.

Shrew trail. Photo by Mary Willson

Bigger tracks were left by an otter moving up Dredge Creek. There was a little bit of open water just below the beaver dam we call Nemesis, and the otter had come up from under the ice of the Holding Pond, gone over the frozen splashes of the dam overflow and onto the frozen surface of Dredge Creek, disappearing upstream.

At the very end of the year, beavers at another lodge came out to work on their caches. Temperatures were absurdly mild, but snow had accumulated near the lodge.

Trail cam photo of a beaver exiting the lodge

While I’m thinking about beavers, I’ll take this opportunity to discuss them as carriers of disease. In a recent essay I mentioned tularemia, sometimes carried by beavers. But we hear more about another ailment, for which beavers are often blamed. Giardiasis is caused by Giardia, a one-celled protozoan that can infest the small intestine, causing diarrhea and other digestive distress in humans, cats, and dogs. There are several species of Giardia, specifically afflicting various kinds of animals (e.g., mice or birds or amphibians), but only one (commonly called G. lamblia) is known to parasitize humans as well as many other mammals. It seems that most of those mammals are asymptomatic carriers of Giardia; at least I found (so far) no reports of sickness except in humans, dogs, cats, and maybe pigs (all of which can also be asymptomatic carriers).

The life cycle of this parasite includes an active, reproductive phase (called a trophozoite), which multiplies in the airless intestine, and an inactive encysted phase. The disease is transmitted by the cysts, which are passed out of the digestive tract with feces (trophozoites may be excreted too, but they soon die). When another animal ingests fecal matter (directly or on vegetation, for example) or water with cysts, the cysts pass into the gut, where they open and release trophozoites, which feed and multiply rapidly. It can take up to two weeks for a new infection to produce symptoms.

Although the cysts can be passed from one animal to another by contact with fecal matter, they are more famously acquired from feces deposited in water. There can be thousands of cysts in one drop of water; they can persist for weeks and be taken up from water drops by swimmers or paddlers. The association with water, and thus with beavers, led to the affliction being called ‘beaver fever’. But that is totally unfair! At least in some areas, humans are the main transmitter of cysts, via improper disposal of sewage. Furthermore, muskrats, dogs, moose and deer, and many other mammals that defecate in or near water also contribute to the spread of the disease.

**Here are the uncommon activities that I noticed in the video. 1. One of the branches selected by the beaver appears to be dead—barkless, budless, and white. In another segment of video (not shown), a similar branch is also taken. No good for the food cache—beavers feed on the bark of living branches. Could they possibly be constructing something else? 2. This beaver held one branch in its mouth while chewing off a second one, and then dragged both branches off to the cache in one trip. The big space between the front, cutting, incisors and the grinding molars to the rear of the jaw is called a diastema. The lips can be closed behind the incisors when the beaver is chewing a branch off, keeping loose chips from going down its throat. This beaver, however, appears to hold the first branch in the diastema while gnawing at the second one.

Thanks to Jos Bakker for the trail cam photo and video.

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Beavers

Beavers (Castor canadensis) live in monogamous pairs (unusual for mammals) with their offspring. There may be several kits of the year plus some one- or two-year olds. Mating occurs in winter, gestation lasts about three months, and kits are born furry and active. They may nurse mother’s milk for a month or so but start eating solid food at an early age. Both parents and the older offspring help take care of the kits, who soon start swimming with the others to find food and observe the repair of dams. Offspring stay with their parents for two or three years before dispersing to find a mate and start their own family. Some have been known to disperse for many miles, including in salt water.

Each family is territorial, claiming a space and defending it against other beavers. Intruding beavers may be treated aggressively, but scent mounds at the water’s edge are used to announce ownership and warn off strangers. The mounds are built of vegetative debris and mud, anointed with urine that isscented by two kinds of glands that secrete oily stuff into the urine just before it leaves the body. Every beaver has its own combination of scents, permitting identification of individuals. Scents on the mound may be renewed frequently, especially if strange beavers are known to be wandering nearby.

Each family typically has one lodge, although sometimes additional simple burrows are used (for example, the male of a pair may move out, temporarily, while the young are being born). Lodges are constructed out of a pile of sticks in the middle of a lake or pond or modified bank-burrows with added sticks on top and near the entrance. A lodge commonly has an underwater entrance leading up to a platform used for drying off and then up to a living chamber, often floored with soft, dry vegetation. The sides of a lodge are usually plastered with mud, inside and out, and there’s a vent at the top (where hoar frost may develop in winter). Lodges in northern regions are quite well insulated, capable of keeping the inside temperatures near freezing even when outside temperatures plunge to minus thirty or forty degrees F.

Dams are built to create ponds deep enough that they don’t freeze to the bottom. They are built of sticks, mud, and vegetation. All members of the family work on building and on repairing breaches in the dam. In flat country, dams can be many meters long; in steep canyons, they can be over five meters high.In addition, sometimes beavers dig canals from the home pond out into the surrounding wooded area; this facilitates dragging branches from the woods back to the pond.

Trailcam photo

Photo by Jos Bakker

In regions where ponds are ice-covered in winter, beavers make caches of branches for winter food. Caches may poke up above the ice but the animals have access to the branches under the ice, and they seldom do much wood-cutting in winter. Although they can use any kind of tree or shrub, willows and aspens or cottonwoods are favorites. They eat the twigs and inner bark, with the aid of special bacteria that break down cellulose (in wood). In summer, however, they depend a lot on softer, herbaceous vegetation.

Beavers are the largest rodent in North America (and second largest in the world). They commonly weigh up to seventy pounds but occasionally exceed a hundred pounds. They’re heaviest in fall, after putting on fat for the winter. The muscular body is capable of hauling large branches for many meters.

Beavers have a very specialized way of life, maintained by behavioral adaptations (building dams, etc.) with a variety of physical adaptations to suit. They can stay underwater for fifteen minutes, if they have to, swimming more than half a kilometer. Their lungs are very efficient, capable of exchanging 75% of their capacity (three or four times more than humans) with each breath. Oxygen storage capacity is not outstanding but they have a high tolerance for carbon dioxide. The mammalian diving reflex works well; when submerged, the heart rate slows and most blood is shunted to brain and heart.

The big incisor teeth grow constantly; chewing wears down the back side of the teeth but leaves a sharp edge where the iron-hardened (and orange colored) front side of the teeth endures. When biting into wood, they commonly anchor the top teeth and actively chew with the lower jaw, which is moved by a powerful muscle in the muzzle. They can close their lips behind the front teeth, keeping wood chips out of the throat. The jaw joint is high on the skull, allowing the hard-ridged molars to meet in parallel for grinding vegetation. Eyes and ears are also high on the skull, so a swimming beaver can sense the upper world; ears and nostrils can be closed while underwater, and a protective nictitating membrane slides over the eyes.

Toes on the big hind feet are webbed, giving good thrust for swimming. The front feet are quite dexterous, the fingers adept at handling small items; they also carry wads of mud and vegetation while a beaver is swimming or walking. The wide tail is a multi-purpose appendage: a rudder when swimming, a brace when standing to chew a tree trunk, a stabilizer when walking on hind feet, sometimes a cushion for sitting on cold or lumpy ground, and the well-known tool for slapping the water to give the alarm signal.

Much of a beaver’s diet consists of woody material that is hard to digest. Beavers (and some other herbivores) have a special sac (a caecum) at the junction of the small and large intestines that houses symbiotic bacteria that break down cellulose. Partially digested food enters the sac, is further digested by the bacteria, and is eventually excreted as a soft pellet that beavers re-ingest, getting the benefit of the break-down activity of the bacteria. Regular pellets of material that did not go into the caecum are excreted as firm lumps of mostly sawdust.

The double coat of fur has long guard hairs covering softer, fluffier fur; the underfur is good insulation, trapping air and keeping water from the skin. The outer fur is waterproofed by grooming the fur with oils from anal glands; toes on the hind foot are modified to improve combing the fur while spreading the oils. That luxurious fur led to rapacious trapping for at least two centuries, resulting in near-extinction of beavers in North America. Sometime in the 1900s, better sense began to prevail and beavers have been re-introduced to many areas in order to reap the many benefits of their activity. Of course, such activities also conflict with some human activities, requiring some compromises. But that’s another long story…

Three winter surprises

Regular bird-watchers spotted an unusual bird in Auke Bay this winter—an American coot. Although range maps show occasional migrants in southern Yukon, at the present time the Auke Bay record is the most northern, according to ebird. Coots are members of the rail family, which includes the sora that is often found in the Pioneer Marsh in summer. Most coots breed farther south of here, but there are isolated breeding populations in east-central Alaska and southern Yukon; this individual is presumably doing its winter things and may migrate north later.

American coot (cleaning up the harbor?) Photo by Kerry Howard

Although they sometimes use salt or brackish water on migration, coots typically nest in freshwater marshes with fairly deep water and lots of tall vegetation. They eat mostly aquatic vegetation, but also take small animals, both invertebrates and vertebrates, at times. Food is gathered by dipping the head underwater or by diving, and usually brought to the surface for swallowing. They sometimes feed on carrion, or steal from ducks, or even snatch flies out of the air. They are strong swimmers; they don’t have fully webbed feet but they have toes with lobes on the sides that increase the size of the foot paddle. 

Coots are strongly territorial, vigorously defending a nesting territory again other coots, as well as ducks, grebes, and sometimes other birds. They are socially monogamous, but in some populations there seem to be floater females that lack a mate and a territory and these females sometimes dump their eggs in the nest of a mated pair. Nests are placed on floating platforms of vegetation, often anchored on the sides by tall cattails and reeds. Multiple platforms are built by each pair and used for courtship, and one is used for the nest. The nest itself is made of small bits of vegetation, making a smooth basket big enough to hold the eggs, although this tends to get trampled flat by the time chicks are present. The floating platform tends to sink, so the parents have to continually repair and augment the structure.

A normal clutch size is about eight to twelve eggs per nest; larger clutches are probably due to the activities of egg-dumpers.However, most of the dumped eggs do not produce chicks, because the nest-owners usually reject the excess eggs. Both parents incubate the eggs, the males mostly at night. Incubation takes a little over three weeks, and the eggs hatch over a span of about three days. Chicks can hop out of the nest and swim around just a few hours after hatching, calling loudly for food to be delivered. Long ago, when I was doing my thesis research in the marshes of eastern Washington, I was fascinated by the goofy appearance of those little chicks, as they swam around after the parents. They have thick black down feathers with stiff, curly, orange tips, a nearly bald head, with some bluish patchesabove the eyes, that’s fringed with red or orange frizzy feathers, and a mostly red bill. It turns out that the oddball coloring is important in stimulating the parents to deliver food. Young birds are chased out of the parent’s territory after about three months, to live on their own and mature at age one year.

Also appearing this winter is another critter that is rare around here: Fishers live in northern forests across North America, but only recently (since the mid 1990s) have they been recorded in Alaska and southern Yukon. These pioneers are thought to arrive via the Taku River valley. Fishers belong to the weasel family (Mustelidae), smaller than wolverines but larger than marten. They climb well, because (like squirrels) they can rotate their hind feet so the toes point back; they are active year-round. Like other members of this family, they are fierce predators, capturing mostly rodents, hares, and grouse, but also eating carrion, insects, and fruit—but not usually fish, despite their name. Fishers are very good at killing porcupines, biting the face and then flipping them over to rip open the belly. They also sometimes prey on marten and weasels, and research has shown that these smaller mustelids tend to avoid times of peak foraging by fishers.

Fisher. Trailcam photo courtesy Riley Woodford

Although males and females mature at age one year, most successful breeding starts at age two. Dens for mothers and kits are usually in cavities in big logs and trees. Kits are generally born in early spring, and females come into estrus and mate a few days later. Sperm meets eggs and a fertilized zygote is formed, but it does not develop very much right away; instead, it just rests in the uterus until late winter, when it is implanted in the uterine wall and active development begins. Litter size is commonly two or three kits, weighing less than two ounces each, which depend on mother’s milk for at least three months and may be weaned at four months. By early fall, they are about full grown; males usually weigh about twice as much as females.

Trailcam photo courtesy Jos Bakker

One more little surprise: a trail cam in the Dredge Lakes area has recorded significant beaver activity in the middle of winter, despite heaps of snow and some very low temperatures. Small trees have been chopped down and hauled away, presumably for food. We seldom see winter activity like this around here. Adult beavers typically live on stored fat reserves while remaining in the lodge in winter. However, kits keep growing through the winter months, and they need to eat. They usually feed on a cache of sticks in front of the lodge, but maybe this family didn’t make a big enough cache.

Winter wanderings

In early January, the ice on the ponds in the Dredge Lake area was good and solid, although there were isolated spots of open water where upwellings slowed the formation of ice. I traipsed around some of the trails and ponds, finding tracks of shrews, hares, and a mouse. Otters had slid over a beaver dam and then up a frozen slough, no doubt hoping to find a fish or two.

One day in mid-January, a friend and I explored a frozen pond, walking on snowshoes to spread out our weight, in case of a spot of weak ice. A little snow was falling, so it was a beautiful walk.

Beavers had made a small food cache near their lodge, including some hemlock branches. There were lots of spider webs and long, trailing silk threads used by airborne spiders. We wondered if any critters, in addition to some spiders, eat that silk to recycle the protein.

Around the bases of several trees at the edge of the pond, we noted the tracks of a small bird, probably a junco. It had apparently inspected each tree base quite closely, possibly picking insects from the spider webs that curtaining the gaps between the upper roots or searching for stray seeds.

A vole had crept out of one bank of a frozen rivulet, crossed he ice, and scuttled back to where it came from. My companion had observed such behavior in other places when the animal was seen to be a red-backed vole, so we assigned that perpetrator to those tracks. Deer tracks crisscrossed the pond ice, and deer had been feeding on the witches’ hair lichens that grew on small trees at the pond edge. My sharp-eared companion heard a brown creeper, which we soon saw as it hitched its way up a spruce trunk.

Many of the alders in this area had neither cones from last summer nor any male catkins for next spring. This was unlike other alder stands we’d seen, so we wondered why this stand was evidently reproducing very poorly. Perhaps the high level of water in the pond was too much for them.

We also noticed that here and in some other places the alders had retained many of their dried and shriveled leaves, instead of letting them drop to the ground. Blueberry shrubs sometimes do this too. In other regions, oaks, beeches, and other trees also retain many of their dead leaves throughout the winter. The term for retention of withered old flowers or leaves is ‘marcescence’. Marcescent leaves have attracted a good deal of speculation about why these plants do this, such as deterring deer and moose browsing, trapping snow for release of moisture in spring, or delaying decomposition until spring, when nutrients are most needed for growth. However, apparently very little investigation has explored those ideas. In some cases, particularly when marcescence is occasional and not regular, the retention of dead leaves may just happen incidentally because the weather suddenly changed in a way that prevented the usual mechanism of leaf-drop (formation of the cut-off or abscission layer at the base of the leaf).

A few days later, along the Auke Lake trail, (and later in other places) we noticed that many of the blueberry bushes had small galls on the twigs, often at the bases of marcescent leaves. The galls are really quite small, and I have to wonder how many times I have walked past them without noticing. They do seem to be more conspicuous against a snowy background…Some blueberry galls are made by midges or wasps, but these did not fit the descriptions of such galls, so the makers of these galls remain to be determined.

Toward the end of January, I went with a friend on the Pt. Bridget trail. Near the trailhead, we found a place where a weasel (I think) had fossicked about in the mud at the bottom of a hole in the snow, and come up to leave a string of its small, muddy footprints on the snow, before diving back down under the deep snow in a new spot. Somewhat to my surprise, the lower branch of the trail, along the edge of the big beaver meadow, was quite passable, provided one didn’t mind a couple of inches of water here and there. A moose had used the trail too, taking advantage of a deeply trenched part of the path—and a small wooden bridge—to avoid some of the post-holing that was required in the rest of the meadow. The bible-camp horses had left ample evidence of time spent on this side of Cowee Creek, on the beach fringe as well as in sheltered places under the conifers. Pawing away the snow and stirring the long, dead grasses, they also had clearly been looking for precocious green shoots under the snow…and had found a few.

As we left the area near the cabin, my companion spotted an owl, probably a short-eared owl, as it swooped down to some bare ground next to a tidal slough (the tide was out). It was probably trying to catch an unwary rodent, but we could not be sure it was successful. It soon flew up into the nearby trees, changed perches, and eventually took off across the wide meadows, screened from clear view by tall spruces.

A day or two later, when Plan A for a beach-walk was foiled by ferocious north winds on Lynn Canal, another friend and I eventually found a sheltered beach near Amalga Harbor. Moving slowly and quietly, we managed to share the beach with a trio of common mergansers that paddled slowly along the tide line. Then they all hauled out and snuggled up in a close-packed row to sun themselves.

I have learned a new word for verbal bric a brac like that found in this essay: bricolage. ‘Tis a very useful word for assortments of diverse things brought together in some more or less unifying way. There may be more bricolages here in the future.

Tracks in December

A warm, very wet spell in early December made the lichens and mosses all perky and colorful. Beavers left their distinctive foot marks in a thin dusting of snow and swam out around their winter caches of twigs, tail-slapping when we passed by. In a ‘real’ winter, they would be tucked up into their lodges, snoozing a lot, talking quietly with their offspring, and occasionally nibbling a twig from the cache. The kits of the year, however, would be chewing twigs all winter long, as they continue to grow. Bears were out and about too, mom and cub leaving their tracks near Dredge Lake, instead of entering into serious hibernation. That entails a profound reduction of metabolic rate, shutting down digestive processes, and very little activity inside the den, quite a contrast with beavers.

Then, in mid-December came a lovely and welcome snowfall, just a few inches at sea level. It wouldn’t last, of course, in this time of warming climate, so I dug up my snowshoes and headed to Eaglecrest. There the snow was maybe a foot or so deep and just right for poking around on a day when the lifts weren’t running. Snow was falling thick and fast, quickly covering any little tracks of mouse or shrew. But under the trees were prints of snowshoe hares. A small-footed canine creature had run across a wide open area, leaving a long, straight line of well-spaced prints. There was no evidence of any human anywhere nearby, so I guessed that a coyote had raced along. But very few critters made themselves visible—a porcupine that seemed to think that if it could not see me, then I could not see it; and one flying insect, probably a stonefly. Nary a bird to be heard or seen not even a hopeful, attendant raven.

A couple of days later, a nice little cold snap meant that even at sea level, there remained a few inches of snow cover. I went out the road to some meadows, where I plonked along on snowshoes—a convenient way to deal with snowy humps of frozen grass. Oddly, there were no shrew tunnels to be seen, nor any squirrel tracks, and again not a bird could be found.

But otters had been quite busy. They had fossicked along a tiny rivulet, trampling some spots quite flat; there were more than one of them, apparently, so perhaps a family of mom and well-grown pups. I lost their trail when it went under the trees where there was no snow. However, a few minutes later, I encountered their characteristic slide marks where they had crossed a snowy, open area, pushing off strongly with the hind legs and gliding smoothly even over flat ground. This is probably more fun than stomping around on snowshoes! A bit farther on, otters had come up out of a tiny stream and snuffled all around the nearly buried ends of several low, trailing spruce branches. What was going on there, I wonder.

Some days later, I looked for tracks in another meadow out the road, but there had been little recent activity. A couple of squirrels had explored the meadow edges, out of the trees and back again, diving under humps of bent-over grasses. Before the last little snowfall, porcupines had trundled over the meadow in several places, on their usual meanderings. They seem to travel quite extensively, perhaps in search of just the right twig to nibble (?). Along a small creek, some critter had burrowed into the bank in several spots—possibly an otter.

Surprisingly, there were no little shrew-size grooves on the surface of the snow, no tiny holes where a shrew dove under the white blanket. Yet this was a meadow that, in previous years, had been laced with trackways of shrews. One shrew had even taken a dive off a vertical mudbank and gone skittering over a gravel bar in a creek. But where are all those shrews now?

A fluttering on the creek-bank caught my eye and eventually turned into a dipper. This bird was foraging along the water’s edge but apparently found little of interest, because it soon took off, upstream. That was the only living animal to be seen, except for one red squirrel crossing the creek on a broken-branch bridge.

Later that day, on another stream, I checked a long-occupied beaver lodge. There were no signs of recent beaver activity here, although the lodge may be currently occupied. However, other woodland folks were interested in the place: porcupines and mink had visited on more than one occasion in recent days. Was this perhaps a multi-species condo? It wouldn’t be the first time that happened.

The slanting light of midwinter that stabs one blindingly in the eye at certain times of day on Egan Drive, did some beautiful things out by the meadows. Some conifer-clad hilltops were brilliantly lit, contrasting with darker slopes below. Light mists collected in the valleys caught the light rays and turned golden. Overhead, some dark clouds gathered amid some white fluffy ones, but bright rays came through the many unclouded areas, where blue sky was a cheery sight.

Lakeside findings

Sometime in mid-January, after a nice cold snap, the temperatures soared into the fifties; even near the glacier it was in the balmy forties. Near the visitor center, sidewalks and trails were slick with ice. A friend and I were headed for a walk on the beach, and we were glad we’d brought our ice cleats.

As we walked down the ramp from the first parking lot, we saw that the pond on the right had a very low water level—the little beaver dam that helps to form that pond was gone. Unfortunately, the lower water levels exposed an area along one shoreline where sockeye spawn. That exposure probably meant that eggs in those redds were killed when temperatures plummeted into the single digits for days at a time, earlier in the winter. Although lots of water was coming down Steep Creek, it didn’t add much to this pond but went into the lake by another outlet.

Once we reached the beach, walking was less slippery but very crunchy. Needle ice had created towers and chasms and a mini Grand Canyon as the thin needles grew up into cold air, perhaps fusing together as they grew. The low brush on the sand flats was liberally decorated with wind-blown gull feathers, both long flight feathers and fluffy body feathers, as if there had been a molting party on the beach.

A large, much battered, log had arrived on the beach. It had been standing in the forest not too long ago: it still had small colonies of moss and lichen, as well as scars from bark-chewing porcupines. We guessed that this old hemlock had travelled from Nugget Valley, down over Nugget Falls, before arriving here. A similar log, probably part of the same tree, had landed not far away, along with a smaller tree with smashed roots. We don’t often see big timbers washed up on this side of the lake. The heavy winter weather, with winds and rains, may have brought the tree into the creek and over the falls; a temporary high water level had stranded the broken trunk on the beach.

In among some bushes at the edge of the beach, we found a dead female northern shrike. The keel on the sternum (breastbone) was very pronounced, indicating that it had little stored fat and may have been starving. However, there was some blood on the face, and when we skinned the head, we found hemorrhage in the skull; there was also some internal bleeding in the abdominal cavity. This bird probably hit a window somewhere, got a concussion, but somehow managed to fly away before it gave up the ghost. We speculated that perhaps it had been chasing another bird (to eat it!) so vigorously that it failed to notice a window—this is something other predatory birds sometimes do too.

Sketch by Katherine Hocker

Shrikes come to us sometimes on migration or in winter, and we see them on the sandy flats near the glacier or out on the edges of the wetlands. They favor semi-open, shrubby habitats, often sitting on top of a bush while looking for tempting prey. They are predators, capturing insects and birds, often on the wing, as well as small mammals. They sometimes capture birds as large or larger than themselves, such as robins and jays. Birds are often captured by grabbing them with the feet, but other prey are more often captured with the bill. The upper bill has a sharp hook at the end and two small ‘teeth’ on the edge of the bill, not far behind the hook. Hook and teeth no doubt help in dispatching a captured prey animal: vertebrates are typically killed by biting through the neck, while insects are generally just crunched up. Sometimes called ‘butcher birds’(in fact their genus name, Lanius, means butcher in Latin), shrikes often impale dead prey on thorns or barbed wire, or in branch forks, to be eaten on the spot or later.

Another interesting find was a beaver-cut branch of feltleaf willow on which the catkins had lost their bud-covers and expanded into nice, fluffy pussy-willows. January is normally too early for this willow to flower, even though it is the earliest one to do so in the spring. We inspected several trees of this species along the lakeshore and found just a few fat buds and two partially open catkins. So the branch we found was well ahead of those that were still on their trees, perhaps as a trauma response to being cut. Plants can respond to damage by releasing enzymes and proteins that produce changes in undamaged parts of the plant; in some cases there is an accelerated development of reproductive organs.

Trailside observations

Here’s an assortment of winter observations that gave pleasure to some trail-walkers.

–Late November, Eaglecrest. Parks and Rec hikers on snowshoes went up the road, but the majority decided to go home for lunch. Two of us went on, over toward Hilda meadows, and perched on a log for a snack. Too busy feeding our faces for a few minutes, we eventually began to notice what was around us. Right behind our comfortable log was a big spruce tree with two lumps at the very top. The upper lump was pretending to be a moss wad, while the lower one was eating spruce needles. Both young porcupines were very wet, but the lower one suddenly roused up and rapidly shook itself dry—moving faster than I’d ever seen a porcupine move. The upper one slept on.

–Late November, Mendenhall Lake beach. A small stream flowed over the beach, creating a little opening in the ice. Three eagles were bickering over the remnants of a salmon carcass, which was probably fairly fresh (judging from the bright red blood stains on the ice). We often see late-spawning coho in the streams that feed the upper Mendenhall (years ago, in December, I counted over a hundred eagles on the stretch of Dredge Creek below Thunder Mountain; they were there because the creek was full of coho). One of the eagles snatched up the tail piece and flew off, hotly pursued by a pirate that eventually won the tasty morsel.

–Mid December, Eaglecrest. Lovely soft snow covered the ground, so animal-tracking was really good. Shrews had been very busy, running over the snow from one bush to another. Lots of other mammals had been active, too: deer, weasel, hare, porcupine, red squirrel, and mouse. Sadly, we found no ptarmigan tracks at all.

–Mid December, Dredge Lakes area. After a deep freeze, a warm spell had melted ice cover and opened up some of the ponds, and beavers had become active. There were new cuttings in the woods, new twigs in the winter caches, and some of the perpetrators were repairing their dams. The Beaver Patrol was called out of its own winter torpor to make notches in a few dams, lowering water levels in certain ponds so that nearby trails were dry , permitting passage of any late-spawning coho, and allowing juvenile salmon to move up and down stream if they chose to do so.

Photo by Kerry Howard

–Late December, Mendenhall wetlands. ‘Twas a very uneventful walk in a blustery wind. But suddenly two small birds blew (not flew!) in and tumbled into the grass. Righting themselves, they revealed themselves as a pair of gray-crowned rosyfinches, a species I’ve seen in upper Glacier Bay and on Mt Roberts, but not out here. That turned the day into a ‘plus’.

–Late December, Dredge Lakes area. Very low temperatures had refrozen almost all the ponds and streams. However, the ditch from Moraine Lake to Crystal Lake had a couple of very small ice-free patches. And there we saw a dipper, bobbing in and out of those dark pools, no doubt very hungry.

Any sensible dipper would go downstream, perhaps to an estuary, where bugs and fish would be more available!

–Early January, Herbert River trail. A mink had coursed along the elevated riverbank, in and out of the brush, occasionally down to the water’s edge. A set of extremely large moose tracks crossed the trail. That long-striding giant was really moving—the foot prints were often five feet apart. The trackway led through brush and over the arching branches of a fallen tree—almost four feet above the ground. Those long legs! I would have loved to watch that beast (from a respectful distance)!

–Early January, Perseverance trail. Recent heavy rains had brought down some small landslides, not unexpectedly. Unlike the trails near the glacier, this one was nearly clear of ice, and walking was easy. There was fresh snow on the ground, up past Ebner Falls, showing up a few porcupine tracks and some very recent red squirrel trackways. A mouse had crossed the trail with big jumps, several times its body length, leaving clear footprints as it hustled into cover across the open trail. I like seeing mouse tracks, in part because I don’t see them very often.

–Mid January, Switzer Creek area. Before the predicted rains and rising temperatures wrecked the lovely fresh snow, we found tracks of deer, porcupine, possible coyote, and a few mysteries. A shrew had scuttled across the soft snow, making a narrow groove marked by its tiny feet. A good find was a trackway of a grouse, striding through the snow and under low-hanging bushes in the woods. This took a few minutes of searching to determine the track-maker, because the new snow was so soft that it often fell down into the tracks, obscuring the prints. But finally we found good marks of three avian toes.

One thing leads to another…

I like to take a walk just to see what I can see, like the bear that went over the mountain, in the old song. You never know what might be found, until you look. Keep looking, and something of interest will turn up. Here’s a recent example—nothing stupendous, but a small story that started simply by noting something unexpected, checking it out, and seeing what developed.

A friend and I walked along a small stream, talking (of course) and looking at wind-throws and mosses and whatever. We spotted something yellow, bright yellow, floating in a backwater. We detoured down to the edge of the stream and checked out the odd yellow object. It was an uprooted skunk cabbage plant; there was the rootstock with many thick roots and two shoots ready for next spring, a green one, partly eaten, and a yellow one that would be next spring’s flowering stalk. I’d never seen the full rootstock before (bears like to dig it up and eat it) nor all those roots, so that was new and interesting. But why was it left there?

As we pondered the floating skunk cabbage, we noted a pile of sticks, just a little way down the shoreline. We quickly saw that this was a winter cache made by beavers—sticks neatly cut and stacked. The cache held branches and twigs of several species: lots of rusty menziesia, some alder and blueberry, and a few hemlock branches. An unusual assortment, in my experience. When they can get them, beavers really like cottonwood and willows, but these were not available in this area.

If there is a cache, there should be a beaver lodge nearby. But we could find no conventional lodge built of a mound of sticks and mud. Maybe these beavers lived in a bank burrow, under the roots of a big spruce tree.The beavers had built a small dam a short distance downstream of the cache. By raising the water level, they would keep the entrance to their living quarters underwater, protecting their ‘doorway’.

As we meandered along upstream, after our detour, we began to note the stubs of cut-off shrubs in several areas. These cuts, and those on the cached sticks, looked quite fresh. Soon we saw several narrow trails running from the creek-edge up into the woods, where there were more cut stubs. A few cut branches had been left along the trails, perhaps to be hauled later to the cache. Some of these trails had been made after a snowfall, and there were dollops of mud and footprints as evidence of recent use. Beavers had used some of these trails repeatedly, so they were well trampled. But we could find a number of clear footprints of beavers’ hind feet. And otters had used the trails too.

These signs obviously meant that the beavers had been active outside of their winter quarters, even though they had a cache. This is known to happen, but usually beavers spend the winter months snug in their houses, the adults living partly off stored body fat, and the young ones, still growing, feeding on the cache. If you stand, very quietly, close to a beaver lodge, you may hear the family members talking to each other, murmuring and chuckling.

There you have it—a simple story, but very pleasing to see how one thing led to another. The story expanded from a single basic observation of something that seemed out of place into a picture of family life and uncommon winter activity. Would we have seen those small trails and footprints as we walked along? Certainly. But we would have missed the skunk cabbage and the cache and the invisible lodge. So the picture would have been sorely incomplete.

March meanderings

Our meanderings in March produced some interesting observations. One day we followed a tiny creek up a hill, through the forest, to a muskeg. At the edge of that muskeg, our canine companion showed great interest in some blueberry stems. We then saw that these stems had been cut by sharp teeth; just a few feet away there was a small, de-barked hemlock stump, and the upper part of the little tree was gone.

Then we found obscure old footprints in the snow that looked like beaver tracks, and down in a tiny gully were several bark-less blueberry stems. An opening in the ice at the bottom of the gully showed where the bark-eater had come and gone, connecting to the main creek. Of course, we then searched on downstream a short distance and soon spotted a small beaver lodge, with a cache of sticks in a pool not far away. This beaver had built several very small dams, creating little pools at the headwaters of the creek.

This is a strange place to find a resident beaver—and perhaps it is just an overwinter bivouac. The creek is extremely small, maybe just a foot wide, and offers little prospect of creating an extensive pond system. The beaver had harvested blueberry, alder, hemlock, and crabapple sticks, in the absence of more usual fare (cottonwood and willow). Soft, green aquatic vegetation would be rare to absent in this little drainage system, so this summer food would also not be available.

We imagined our beaver—probably a young one—swimming in the salt water from its natal stream as it dispersed to find a home of its own. Then it must have sniffed out the fresh water coming down to a beach and explored its way up to the headwaters of this little creek. At least it could overwinter here.

We were not the only ones to discover the beaver signs. A wolf had left it gigantic pawprints rather recently, as it checked out the lodge and cuttings before cruising over the ridge.

There were other things to see, too: Tracks of deer, porcupine, and grouse. Grouse scat that looked as if the bird had started to shift from winter food to soft summer food. An old, rotten log riddled with beetle borings full of frass (beetle feces) that was better preserved than the wood itself. Very fresh bird scat on the trail, berry-stained and full of false lily-of-the-valley seeds.

Photo by Katherine Hocker

A big, dead, double-trunked shore pine claimed our attention. As do the great majority of dead pines we’ve looked at, this elegant specimen showed a strong twist to the right. In fact, I’d say that over ninety-nine percent of the many dead pines we’ve inspected have this right-hand spiral in the wood. So far, we have found no cogent explanation for this observation; all the suggested published ideas fall far short.

On another hike, at the edge of a muskeg, we were entertained by a raven that flew overhead and dropped something—thud—onto the snow next to the trail. It was a wad of moss and tiny twigs. Oh, I said—nesting material. But something didn’t look quite right (and would moss and little twigs make a thud??). So I reached out and turned over the wad. It was nesting material, all right, but not for a raven. It was an old robin’s nest, mud-walled inside the moss-and-twig mix, and frozen solid. Now the question became—what was that raven really doing? Bombing us, as message? Playing games?

Bizarre February

This had been the winter that wasn’t! On at least one day, the temperatures soared into the fifties. Many days saw temperatures in the forties. The snow alternatively got crusty (at night) and soggy. It became difficult for Parks and Rec hikers to choose a trail for their twice-a-week outings.

We tried the Herbert Glacier trail. It worked fine for skiers, but snowshoers were in for serious ankle-twisting on the unevenly packed snow. Not fun. The Auke Nu trail was pretty good in most places, with only occasional sections of frozen, deep bootprints that are so difficult to walk on; the descent was facilitated by snowshoes, after the sun had softened the snow.

When the group decided to go to Peterson Lake, a few hikers rebelled, thinking that snowshoeing this trail would be as miserable as the Herbert trail. Walkers that had passed when the snow was soft left deep bootprints, and now these had frozen. Some of the would-be hikers, weary of lurching over the frozen bootprints, turned back and went home. The rebellious ones went, instead, to the Eaglecrest area, on a day when the lifts were not running, so the ski-runs were not full of fast traffic.

We wandered around, on and off the trail, enjoying sunshine and peace. Mount Ben Stuart was spectacular: the slanting sun brought the lateral ridges into high relief and framed the snowy twin summits against a backdrop of purple-black cloud.

The snow was firm enough to walk on but soft enough to show the tracks of a busy animal community. Peripatetic porcupines had ambled here and there, leaving a web of tracks over a wide area. A skinny, flimsy spruce branch whose tip was well-buried in snow had been recently de-barked by a hungry porcupine. It was surprising that a hefty porcupine was evidently able to climb several feet up the spindly, wobbly branch, gnawing all the way.

Red squirrels had made little highways from tree to tree. One was actively moving spruce cones from one hole to another. Snowshoe hares left evidence of their passage. A weasel had bounded down a long meadow, leaping several feet with each bound, neatly placing its hind feet just on top of the prints left by the front feet.

The snow was very deep but in a few places there were openings down to running water. At a couple of these water-holes, we found concentrations of the distinctive tracks of a beaver. We couldn’t believe our eyes, so we tried to make those tracks belong to almost anything else; but in reality, there was no mistaking those prints.

The big mystery is why a beaver would be up there in February. Beavers usually hunker down in their lodges in winter, but this one was unseasonably active. This isn’t the first time we’ve seen beaver activity at Eaglecrest; a few years ago, one burrowed into a streambank and tried to build a little dam. The divide between the Fish Creek drainage and the Hilda Creek drainage lies at Eaglecrest, and when young-adult beavers from lower down in those drainages leave their natal ponds in search of a new home, they may sometimes go uphill. But to find one in February was really weird; perhaps our bizarre weather caused a young adult to start its dispersal earlier than usual.