Four wintery walks

sun and shadow and snowy tracks

The thermometer at my house read eleven degrees (F) after a clear, starry night; the sky looked clear, although the sun wasn’t really up yet. Juneau had recently enjoyed about six feet of lovely snow, but many of the trails had not yet been used much. In search of a well-packed trail, a friend and I headed for the Boy Scout beach trail.

All went smoothly until we reached the junction where the trail splits three ways, and none of the splits looked good. We chose to go right out onto the goose meadow and immediately found ourselves breaking trail and post-holing through deep, crusty wind-blown drifts. Even following in the footprints of my companion, I (weighing forty pounds more) plunged and lunged, knee-deep and more. However, a hundred yards or so farther on, walking became a pleasure again, because the low vegetation was almost clear of snow, thanks to some recent super-high tides that left a few scattered cakes of frozen foam and to the wind.

Post-holing again out to the beach by the iconic cottonwood tree, we decided not to face the stiff, cold north wind that was churning up waters out in Lynn Canal. So, instead of coming back on the big, exposed beach, we turned toward the camp buildings, found a log, and had a little picnic in the sun. As soon as we got out our thermoses and lunch bags, two importunate ravens landed on the beach right in front of us—they knew the drill! Of course, we obliged them, tossing out bits of sandwich that they promptly snapped up. But they eyed a fragment of a sugar-snap pea with great suspicion and avoided going close to it—no veggies for them! One of them chose to sit next to us on the log for a while.

On this day in mid-December, the morning sun barely cleared the horizon. On the upper beach, I noticed that every isolated pebble cast a shadow much longer than itself, making a grid of conspicuous black stripes that called attention to each pebble.

The Chilkats across the canal were spectacular: the low morning sun made sharp contrasts between the sun-bright south-facing slopes and the intensely blue-shadowed north slopes. Behind us, the trees on the hillsides were individually defined by the snow they carried and on the peaks the snow delineated the minor topographical features very nicely.

Few critters were visible on this walk. A seal cruised by, just offshore, and gulls fossicked about in the tidal wrack. A wren zipped rapidly from trailside to shelter under some roots; they are so tiny, I wonder how they stay warm on frigid winter days. No midges or spiders crept on the snow surface.  But there were tracks of mink along the river, red squirrels in the woods, ermine and vole at the edge of the meadow; one or two small birds (who?) had hopped and run in the beach rye lining the meadow trail. A low-flying raven (?) left the mark of one wing-tip in the loose surface snow.

The next day was mostly sunny and, again, very cold (seven degrees at my house in the morning). I opted for snowdrift-free walk on the dike trail. A few tracks of squirrels and maybe an ermine were the only natural history notes of the morning until I had almost finished the walk. And there in the stand of willows was a female pine grosbeak, busily nibbling buds. I frequently see these grosbeak in fall and winter, as they forage on high-bush cranberry, carefully extracting the seed and dropping the red fruit pulp—the opposite treatment from that of bohemian waxwings, who eat the fruit and excrete the seed.

A couple of days later, the cold remained (just six degrees here). I had an idea to try some of the lower meadows along the Eaglecrest Road, but roadside parking was hard to find and the thought of plowing through deep snow, even on snowshoes, was daunting. So, on up the road to the Lower Loop, nicely groomed and unoccupied. The sun couldn’t make it up over the peaks, but ‘shoeing was easy.

There was not a live critter in sight but there were plenty of signs of life. A porcupine was into long-distance travel, heading straight across the meadow, not stopping to forage. Ermine had cruised all over the meadows in circuitous routes, looking for a juicy morsel. Snowshoe hare tracks were abundant, mostly under sheltering conifer branches or going from one shelter to another. Grouse or ptarmigan had been active, inspecting salmonberry and blueberry bushes for tasty buds and sometimes staying long enough to trample the snow flat. Except for a few squirrel marks, the smaller folk had left no signs on the surfacebut were no doubt active below.

A day or two later, it was still very cold. A group of friends strolled the dike trail, enjoying the bright sunshine as the sun crept over the peaks. A dusting of fluffy snow lay atop a snow crust. Several voles (I think) had made sorties out into the grassy areas, circling back to the trees or to holes under grassy tussocks; we noted at least seven of these trackways, well separated from each other. Looking through the chain-link fence and across a ditch, we saw tracks on a big snow drift that looked like Two-toes—but how could a deer walk up that crusty snow on those thin legs, without punching through, when humans (on our side of the fence) generally ended up post-holing?

February scrapbook

warm and bright observations in an icy world

Winter finally arrived sometime in early February, with good snow on the ground and very cool temperatures. I’ve lived here for three decades, so I’m quite well acquainted with Juneau’s local microclimates—it’s often warmer, wetter, and windier downtown than it is in the upper Valley where I live. But I recently saw what seemed to be an extreme case: as I drove Out the Road one morning, I left my house at a temperature of minus six degrees (F), then the car thermometer registered plus thirteen, dropped quickly to minus two, and rose again to plus fourteen degrees. That’s a twenty-degree span in fewer than twenty minutes. Extraordinary.

Along the way, I passed a place where a thin blanket of white mist lay over an estuary and shallow inlet. We often see this phenomenon in cold weather and sometimes call it ‘sea smoke’ or ‘steam’. But it’s not steam…steam is hot water vapor, and it’s not really smoke, either…not full of organic particles and carbon dioxide. Whatever the right name is, the cause is well-known. Liquid fresh water cannot be colder than thirty-two degrees (or it would become ice). So the surface of the estuary was warmer than the frigid air and water was evaporating. When that rising water vapor encountered the cold air, which holds less water than warm air does, it condensed into small droplets that hung over the water surface in thin mist.

I met a friend at the Point Bridget trailhead and we set off to see what we could find. The best find was the trail of an otter, bounding and sliding over flat ground and out onto the frozen beaver pond. Even on the flat, this otter was sliding as much as eight feet before gathering itself for another bound and slide. Wouldn’t that be fun to do! Blowing snow had drifted into some other tracks, but we found those of porcupine, moose, and a deer or small moose; red squirrels had made new highways under some of the trees.

A stiff breeze was churning Lynn Canal into a froth and big waves were roaring onto the beach where we look out at Lion’s Head. By the time we got there, it was afternoon and the wind was increasing, as it often does then. So the beach log where we often perch for lunch was not very hospitable. Even behind the beach berm, the wind was making the emergent tall grasses lie almost flat on the snow. So we found a windbreak in a sunny spot for a comfortable lunch.

Home again, with temperatures a relatively balmy plus sixteen degrees. The birds were active on the feeders, among them ‘my’ pair of red-breasted nuthatches. They brought two youngsters to the feeders one day last summer but they have apparently stayed on their territory for the winter. Each pair is socially monogamous; there apparently have been no studies of extra-pair matings (which are common in many other birds). Nuthatches defend their territories from other nuthatches; the male is especially vigorous in defense when the pair is excavating a nest in a dead tree. They also defend the nest cavity from red squirrels, which are potential predators of eggs and chicks.

Nuthatches have the odd habit of putting sticky conifer resin around the opening of the nest cavity. It is thought that this helps deter predators. One study found that more resin was placed around the nest entrance right after a face-off with a squirrel. Rarely, however, this tactic backfires, and one parent gets inextricably stuck in the resin and dies.

After the nest is built, females incubate five to eight eggs and the male brings her food. Incubation takes about twelve days and chicks stay in the nest for almost three weeks. Sometimes the male joins the female in the nest during incubation and brooding very small chicks. After the chicks fledge, the parents feed them for another two weeks and then the youngsters sometimes stay with the parents for many weeks, or they may become independent and disperse. Most nuthatches probably live only a few years; the maximum known lifespan is just over seven years.

Nuthatches forage by walking up and down and around tree trunks and big branches, especially in winter, presumably because dormant arthropods lurk in the crevices. They can walk head-first down a tree trunk and even walk upside down underneath a branch. They have a very short tail, not usable for bracing again the wood as woodpeckers and creepers do. Having a relatively long hind toe helps them scamper down and sideways. Outside of the winter season, they also forage on twigs and leaves, even on the ground sometimes, and occasionally catch insects out of the air.

Photo by Gwen Baluss

Captured food is often cached in holes and crevices, sometimes covered with bits of lichen or bark. A big item is wedged into a crack and then hacked into smaller bits (unlike chickadees, which hold such items in their feet). In fact, their English name may have originally been nut-hacker. At a seed feeder, nuthatches can be very choosy, carefully selecting the largest and heaviest items.

Little appears to be known about how they manage in extremely cold weather. They do join mixed-species foraging flocks in winter, along with chickadees, kinglets, and other small birds. Presumably their insulation is quite good, but they don’t seem to roost communally or have elevated metabolic rates then (as some other birds do). More questions to be answered!

Strange winter

a bricolage of encounters and observations

December was so warm that beavers stayed active, collecting branches for their winter caches and dam repairs, leaving trails in a thin snow cover. The snow recorded the passage of an otter, sliding over a sand bar in Eagle River. That thin layer of snow also collected a tremendous number of male spruce cones, raising the question of why the trees retained those cones so long after the pollen was shed.

January was more wintery, with a good snowfall and nice cold temperatures. Ptarmigan had come down to the Treadwell Ditch, wandering widely and seldom stopping, apparently not finding much to eat.

On the lower ski loop at Eaglecrest, wildlife had been very active. Porcupines, large and small, had wandered far and wide, leaving their broad furrows and baby-size footprints. As we perched on a log for lunch, a flock of chickadees and golden-crowned kinglets conversed and foraged in a nearby hemlock.

There were lots of deer tracks, of different sizes. The deer trails often followed the edge of the woods, and the lower branches there held only fragments of the dangling lichen Alectoria, suggesting that the deer had been eating one of their good winter foods. Bunchberry plants had been grazed from the bases of trees, leaving stem stubs where deer noses had cleared the snow.

Shrews had left their tiny furrows on top of the snow, leading from one dime-sized hole to another, where a shrew had come to the surface and gone back down under the white blanket. Why do they come out in the open, sometimes travelling many yards before diving back down? That’s a long way to go for the occasional spider crawling slowly on the surface…

Driving out the road, we noticed many small groups of varied thrushes picking small items from the roadside. What are they getting? Grit? Blown seeds? Salt? A subsequent stroll on the Boy Scout beach discovered numerous tiny pinkish shrimp washed up (why?) by a moderately high tide. Ravens attracted by our lunch group lined up on a log came in to scrounge our offerings and then nibbled some of the shrimp.

The long, deep cold in January kept the snow beautifully, brightening the landscape. At my house the temperatures didn’t rise above freezing for many days, dropping to single digits at night. Mrs Nuthatch came to the peanut butter feeder long before there was decent daylight. Mink had been active in several places. One explored the shores of Norton Lake in the Mendenhall Glacier Rec Area, not stopping and clearly going Someplace. Another mink, at Eagle Beach, had made tunnels in deep snow, periodically popping up to the surface but diving right back down. ?Searching?

The prolonged deep freeze let me hope that the ice on the ponds in the MGRA would be sound enough to walk on (with snowshoes, to distribute the weight). However, the ice on Glacier Lake was chancey: there were a few spots of open water and some mushy places. So we crept around the edges to see what we could see. An otter had better travelling over the ice, leaving its trail of prints and a slide between spots where it had dug down through the slushy snow. Was it thinking about getting through the ice to look for fish?

Then warmer weather came back, with rains that ruined the lovely snow. At my house, a raven has come to expect occasional tidbits on my deck railing. One morning I put out some pieces of pie crust. In it came, as if it had been waiting, and grabbed the larger chunks. Then, with the bill crammed, it tried to collect the smaller bits. No luck. So it figured out that it had to drop the big ones, eat the small ones, and then pick up the big ones to carry away.

Down on the surface of my pond, I noticed a female mallard, grubbing for spilled seed in the slush under the suspended feeder. She dug and dug, sometimes burying her whole head, for more than ten minutes. Then she walked to open water downstream, leaving her wide trail in the slush. Late in the afternoon, she came back and did it all over again. I bet this duck is one that hung out here in the summer and remembered this food source.

Winter wanderings

ptarmigan tracks, porcupine trails, a busy hare and a winter-kill

There aren’t many activities I enjoy more than simply prowling around the forest and meadows, looking for signs of animal action. Sometimes I go solo; when I’m lucky, I have a companion or two. All this recent sunshine has enticed me out several times; it’s a shame to waste a day of sun in Juneau by staying indoors! So here are some observations (and questions) from some little explorations in the last few weeks.

–Cropley Lake: a ptarmigan had landed, sinking down a few inches in the soft snow. But for some reason, it took flight immediately, leaving a few running foot prints and two sets of wing prints, the second one very faint.

–Mendenhall Lake: ptarmigan often come down from the alpine zone in winter and forage in the shrubby flats near the lake. Sometimes I’m lucky and actually see the birds, but this time I only found a trackway where the ptarmigan had run, with long strides, from one thicket to another. There it had nibbled on willow buds, leaving barren stems.

–Crow Point near the Boy Scout camp: a porcupine had trekked all the way across the wide meadow where the geese commonly graze, from the hillside out to the spruce groves above the beach. In one of the groves we noted a cluster of young spruces with dead tops. Closer inspection revealed that the tops of the trunks and some of the upper branches had been de-barked. But this had not happened all at once: some gnawings were recent and the twigs were not long dead, but others were gray from long exposure. Thus, it seemed that porcupines had foraged here repeatedly, and I have to wonder what made that particular cluster of trees so attractive.

The beach itself was covered with bird tracks: gulls, crows, and something smaller, whose tracks were very indistinct. I was interested to note that a vole or mouse had ventured well out onto the sand; what was it after?

–Low elevation muskegs off the Dan Moller Trail: This little exploration was quite productive. We found a place where a hare had run back and forth, stopping long enough to eliminate (colorful!) waste products and nibble the buds from the tip of a spruce branchlet that had been cut from a low-hanging branch several feet away. A perambulating deer had cropped the very tips of some blueberry bushes, taking just the tenderest bits and buds.

hare-ate-spruce-buds-KMH-(2)
That red isn’t blood… it’s hare urine! Photo by Katherine Hocker

The snow was so deep that most small mammals could just burrow around under the white blanket, safe from aerial predators at least. The only small mammal tracks we saw were in the bottom of a tiny gully where the snow was thin. The mouse had run across the ice in one direction, but then walked back.

A surprising find was a dead Steller’s jay, lying toes-up under a tree. It was emaciated, with no fat deposits, so the keel on the breastbone was very prominent. Later examination revealed a digestive tract empty of all but little stones. With all the bird feeders in most human neighborhoods, it seemed strange that this bird would starve.

New Year’s Day 2012

mustelids and lichens in the muskeg lands

Snow was falling, snow on snow, but—unlike the song—this midwinter day was not bleak at all. With two friends, one two-footed and one four-footed, I set out to explore the forest and small muskegs near the Auke Bay school. This was not our original destination, but we got part way out the road, watched a truck slither and spin out over both lanes in the unplowed slush, and decided we’d find a place closer to town. I’d never been in the area behind the school before, so everything was new to me.

No birds seemed to be active there, but we soon found the trail of a short-tailed weasel, also known as ermine, particularly in winter when the fur is white. It had popped out of a hole roughly the size of a fifty-cent piece, looped over the snow for a few feet, and then dived into the snow again. Both of these snow-holes led to open spaces under shrubs bent under the weight of snow, where mice or voles or shrews might provide a snack. The long, narrow bodies of the weasels allow them to follow their prey into small tunnels.

On the surface of the snow, we could easily see their footprints, with the rear feet landing where the front feet had been, as it took off in the next leap. Each leap covered about a foot of distance. They have such short legs that the fastest way to get around is bending the long, sinuous body to extend the stride.

Short-tailed weasels are ferocious predators, dining on mice and other small mammals by preference, but sometimes eating birds, insects, worms, and even young snowshoe hares. Males weigh up to about seven ounces, but females are considerably smaller. They have high metabolic rates and have to eat a lot every day; females with litters may kill four mice a day.

A bit farther on, we found the trail of a bigger relative of the weasel. This path led hither and yon through shrub thickets, briefly into a tiny rivulet, along a log, under some low-hanging hemlock branches, and into still more thickets. Although we occasionally lost the trail for a little way, we eventually followed it for several hundred yards. We decided the trail-maker was probably a pine marten, partly because the footprints seemed a bit too big and furry for a mink, and partly because no sensible, hungry mink should be so far from the delicacies along the shore.

Trudging through the brush can be easier in winter than in summer. Snow presses down many of the blueberry and menziesia branches, and the two humans on snowshoes could stomp over the bent branches. Our canine companion was less fortunate; her snowshoe-less feet sometimes plunged through the brush piles, to the full length of all four legs, leaving her to wallow her way out.

Even though our broad feet helped us through and over the bushes, we still emerged with our knit caps full of lichens and twigs. And every so often a snow-laden arch of branches would give way, depositing us unceremoniously into a hole. We think this is fun, apparently, because we keep doing it.

Along the way, we noticed an area with a spectacular display of beard lichen festooned on almost every branch. Some of the strands were easily over six feet long. We wondered how it is that there are localized ‘hot spots’ for this lichen. Environmental conditions for good growth, including light and lack of aerial pollutants, must be part of the explanation. But it seems likely that dispersal patterns also contribute to the patchiness of strong lichen colonies: Spores and fragments of lichens are carried on the wind, so the direction, speed, and timing of winds would probably deposit them in semi-predictable patterns. Here’s a complex research problem awaiting a clever young scientist.

Stories in the snow

a snowy ramble reveals winter action

I love to go a-wandering along a snowy trail, looking for signs left by others who’ve been out on their business of living. A recent prolonged cold spell had kept the snow soft, preserving evidence of a very busy wildlife community along a local creek.

Mink tracks rambled along the creek-side, dipping down to the stream and curving up into the forest. The footprints were bigger than those of a second mink that traveled part of the same route, so my naturalist friend and I guessed that the first mink was a male. His trackway led a long way upstream on one side of the creek and seemed to circle back down on the other side—at least the footprints were the same size there. This might have been a male patrolling his territory.

Everywhere, we found the delicate, stitchery trackways of small rodents. According to the books at hand, mice are likely to drag their long tails, flipping them to the side as a counter-balance during sharp turns, but voles don’t usually show tail-drag marks. If that’s right, we had both mice and voles, especially on one side of the creek. The tiny trackways of shrews were less numerous.

Snowshoe hares had been busy, especially on the other side of the creek. Trackways led up to the streambank, then away, then back to creekside, then away. It was as if the hares wanted to cross the fragile ice but, lacking the nerve to do so, just dithered along the bank.

A bird had hopped about extensively in and out of some brushy areas. The tracks seemed too small to be those of a junco. Then we found wing-prints where the bird had flitted a short distance to a new site, and the length of the wing was clearly too long to belong to a junco. My guess was possibly a varied thrush, some of which overwinter here.

The only actual bird we saw was a brown creeper, hitching its way up a tree trunk and flying down to go up the next tree—their typical foraging pattern as they search for tiny bugs in the bark. According to the literature, creepers commonly concentrate their efforts on trees with ridged bark, the deeper the ridges the better; this kind of bark harbors more insects than smoother bark.

A few deer tracks, both large and small, appeared as we walked along. But there was much less deer traffic here than, say, in Gastineau Meadows, where peripatetic deer had cruised all over the place.

My friend called to me: Come look at this! I saw a shallow groove in the snow on the streambank and, without thinking, said: Oh, a shrew trail. Look again, said my friend. Ah—there’s a faint yellow stain at the bottom of the groove. And here, where I had casually supposed my ’shrew’ had dived under the snow, was—not a burrow at all, but just a deep dimple. My friend, who is smarter than I am, said: I think a bird, maybe a kingfisher, perched on that branch near the edge of the stream and projectile-defecated a jet of hot poop, melting the groove in the snow. So we said: Well, if that’s so, then in the dimple at the end of groove there should be a little wad of solid waste. And yes, indeed there was! Good detective work, friend!

A final little treasure on this walk was a dead red alder that sported a beautiful array of conks (or shelf-fungi). The living conks all had a slightly soft pile of white stuff at their lower edges. This stuff had occasionally smeared sideways over the bark, showing that it had been soft when the temperatures were above freezing. What is this stuff?

Phellinus-conks-kathy
Phellinus conks. Photo by Katherine Hocker

I took a sample to a local forest pathologist, who put it under his microscope. He said that the white material was certainly fungal mycelium (the technical word for the mass of filaments that grow through the wood before producing the spore-bearing conk). However, without DNA work, there’s no way to know if it belongs to a parasitic fungus growing on the conk or to the conk species itself, because this kind of conk (of the genus Phellinus) often grows some of its own filaments right down through the conk itself. So we ended our walk with one more mystery.

Beavers in winter

what’s it like inside a lodge?

On an October exploratory excursion, we encountered a well-built beaver lodge, one we hadn’t known about before. The sides were freshly packed with mud, effectively waterproofing and insulating the lodge for winter. I needed to refresh my failing memory on what it might be like inside a beaver lodge in winter, so back to the literature I went.

Beavers seldom venture into the open air outside the lodge in winter, when ice covers their ponds, so for months a family of beavers breathes ‘indoor’ air, using oxygen and generating carbon dioxide. Beaver lodges have underwater entrances, and mud seals the walls, so air exchange is effected through a ventilation hole in the roof. Apparently this roof vent is sufficient to keep carbon dioxide from building up and allow an influx of oxygen, because when researchers measured the levels of those gases inside an occupied lodge, they stayed nearly constant.

 

Temperatures inside a well-built lodge also do not vary much. For example, when outside temperatures drop to minus twenty degrees centigrade (about minus four degrees Fahrenheit), inside temperatures remain just above freezing. Thick walls obviously conserve more body heat than thin walls, so inside temperature varies more if the walls are thin.

If beavers had to live outdoors in winter, for example at an air temperature of minus twenty degrees centigrade, their metabolic rate would almost double, compared to that at normal lodge temperatures. They might not be able to eat enough to stay alive under those conditions.

Beavers don’t hibernate, so they need a supply of energy throughout the winter months.

Although beavers make a pile of cut branches in front of the lodge as a winter cache of food, the cache does not contain enough food for a whole family of beavers (adults, yearlings, and kits) if they eat as much as they do in summer. Instead of eating lots of cached bark and roots, wintering adults reduce their energy demands by lowering their metabolic rate and body temperature and conserve energy by not moving around very much. The adults put on large amounts of fat in fall, partly in the body cavity and under the skin, but especially in the tail: the amount of fat in the tail in winter can be ten times what it is in summer. This stored fat is used up over the winter, so the adults lose weight.

In contrast, the kits and yearlings maintain their body temperature and metabolic rate, which is higher than that of adults, and they keep on growing. So they eat a lot, and the adults often bring the sticks into the lodge for them to eat.

Just inside the entrance of a lodge is a ledge to which beavers bring sticks from the cache—the winter dining room, so to speak. Here a wet beaver drip-dries as it eats the bark from the branch. A slightly higher ledge is a dry sleeping place where the family spends most of its time in winter. Adults, yearlings, and kits all huddle on the sleeping platform, dozing and occasionally grooming, and sometimes ducking outside to retrieve a cached stick or to defecate and urinate.

lodge-XS-hocker
illustration by Katherine Hocker

If one is very quiet, and the winds aren’t howling nor the rains pounding down, it is sometimes possible to stand next to an occupied lodge and hear the residents chewing on retrieved sticks.

Snow!

a heron in the forest, a frozen feast, and raven excavations

The first halfway decent snowfall in mid November drew me out to look for animal tracks and anything else of interest. I went with a friend to the forested banks of the lower reaches of Eagle and Herbert rivers. Deer, both big and small, had wandered extensively throughout the area. Mink had a regular route along the top of one river bank. Porcupines had been out before the snow stopped falling, but squirrels left very fresh prints. Just as we were commenting on the lack of bird tracks, we happened upon some clear prints left by a heron strolling through the forest.

Then we heard a ruckus made by some squabbling ravens, over on a sandbar across the river. We approached quietly, with several trees (and the river) between us and the gang of ravens, but they spotted us immediately and took off. A number of magpies then moved in. The big attraction was the bony torso (spine and rib cage) of a deer, already well picked-over but still clearly worth serious attention. We settled down among the trees to watch.

We counted at least nine magpies; the precise number was not readily determined, because they were constantly flying to and fro: pecking and tugging briefly, then departing for a few minutes, and returning to grab another morsel. Were they caching these little bits of meat or just going off to eat each bit in peace? All those magpies seemed to be able to forage together without altercations (unlike the ravens); there apparently was room around and even inside the rib cage for them all.

A juvenile eagle arrived, briefly scattering the magpies, but they soon moved in again—on the side of the carcass away from the eagle. This was not very profitable feeding for the big bird, however, and it soon departed. Meanwhile, one or two ravens cruised by, or perched up in the spruces, occasionally hopping over the sand toward the bones but nervously taking off without feeding there again. Maybe nine magpies were too much for them, but I think they knew we were still there and did not like being watched.

A few days later, we had wonderful snow and lots of it. Spruces bore thick white blankets on drooping branches and alders bent almost to the ground under the heavy load. Rather than do the various tasks I was ‘supposed’ to do, I took off out the road to do a little exploring on snowshoes. ‘Twas the first time on ‘shoes this season, and it showed (sadly). Tracking was good, however: fresh deer trails, old otter slides leading from one patch of open water to another, not-so-old porcupine trails, deeper than the otters’ marks, a few squirrels, and a mink.

Two ravens were assiduously digging in the snow, in selected spots, tossing snow aside with their bills. Sometimes they dug down several inches, apparently getting very small, unidentifiable items. What could they be finding, and how did they know where to dig? I shared a few crumbs with them.

That lovely snow didn’t last, here near sea level. But I sure liked how it brightened up our short days!

Wonderful Winterland

herons, swans, and an eagle’s dinner

I love just prowling around in the snowy woods, looking for whatever presents itself. Solo or shared, there is usually something of interest. Here are a few examples from the past two months.

In November, just after the first good freeze-up, I poked around on the Old River Channel (think Mendenhall River, maybe a hundred years ago or so).A great blue heron had paced–in vain—along the now-icy runnel below a beaver dam, where no fish could now be grabbed. Then I saw some huge prints of webbed feet, bigger than my hand. No goose or duck or gull; this could only have been a swan. Following the tracks, I came to a place on the ice where the swan, perhaps with some friends, had dithered around for a while. They too were cut off by the ice from any tasty green vegetation in the water below. As they dithered about, they left samples of previous meals on the surface of the ice.

By now, my path had been crossed by another retired biologist and well-behaved canine companion. Together we inspected the digested remains of swan dinners and concluded that the swans had nibbled on their own excreta, recycling the material and probably extracting more nutrients. Well, if you can’t reach the fresh stuff, perhaps this is a reasonable alternative! I wonder how often they do this—is it only occasional, for instance when ice blocks the access to fresh greenery?

Some of those huge webbed footprints led away from the resting and feeding site. They gradually got farther and farther apart, until the last strides were separated by at least seven feet. The very last one was matched with the brush of a single wingtip in the light snow. A seven-foot stride on shortish legs meant that bird was really hurtling itself into flight.

Although swans sometimes overwinter in Southeast, most of them migrate to slightly more southerly realms. Several swans had been seen in the upper Mendenhall River on the days before my little exploration, but increasing ice cover was making further stay a hungry proposition for them.

In midDecember, Out the Road (in Juneau that is a place, not just a direction), we noticed two eagles hunkered down on the bank of a small stream. They were intently staring at a dark, furry object in the water. We were ‘dying’ of curiosity, of course, but didn’t want to disturb the eagles. So we went on, saying we’d stop to look on the way back. When we did so, the eagles and the dark object were gone. All we could do, then, was check out the spot for any signs of what had been there. We found a beaver tail, some gobbets of flesh, and a rib. Perhaps the carcass had shifted farther under the ice at the edge of the stream, but maybe more likely, one of the eagles had appropriated the thing for itself. By midDecember, beavers are usually hanging out in their lodges, awaiting ice-out. So why this one was here, and how long it had been there, was puzzling.

Mid December also found us wandering around some of the ponds in the Mendenhall Glacier Recreation Area. Walking over the ice on the ponds gives one an entirely different perspective from one on the trails or in the thickets. A bonus is walking in actual sunshine! One pond has several beaver lodges that, in four years of monitoring, have never shown any sign of current occupancy by beavers. This time, we noticed small holes in the side of two lodges, with small footprints making a trail right into that doorway. It looked as if mink had moved in. Out in the middle of the pond there were three round holes in the ice, kept open, perhaps, by mink diving in for fish.

Just before Christmas, I ambled over another pond. By now, we had had several more nights of single-digit temperatures, and the ice was really solid. But there were two holes in the ice that had just recently frozen over. And there was a trackway, made by several animals, running from one hole to the other, and then on toward shore. Following these round-pawed tracks, I came upon a sizable hole under some tree roots, and there the tracks ended. I surmised that a family of otters had used this hole as a part-time den; in the past week or so, a group of three pups and an adult (presumably Mom) had been seen fishing in the few ice-free spots that remained.

Out and about

bits and pieces from December

I try to get out for a walk every day, whatever the weather, although the weather may determine the length and location of the outing. How much I see of natural history interest varies greatly, depending on many factors, including a perceived need to watch the footing in sloppy mud or on slippery ice or wet rocks, sometimes a wish to be a bit sociable, or even do some serious (or not-so-serious) thinking. But most of the time, I like to keep my eyes and ears open to what is around me. So here are some bits and pieces from December.

As a cold snap settled in, Mendenhall Lake grumbled and growled and muttered in a long-winded soliloquy—the ice, talking to itself as the water froze and expanded. Smaller ponds were less loquacious but still murmured and popped at a lower decibel level. Meanwhile, overhead, large flocks of pine siskins flitted from spruce to spruce, sometimes swooping high over the canopy before disappearing in the crown of another cone-laden spruce.

In between short periods of deep cold, however, we had spells of surprisingly warm temperatures, turning our little bit of snow to slush and sending meltwater down over the existing ice on streams and ponds. Open water formed at inlets and outlets of ponds and along the fringes of Mendenhall Lake. A reliable observer reported seeing a beaver swimming in Mendenhall River in late December, when local beavers are normally snug in their lodges, sleeping or nibbling from their winter cache of twigs. That beaver was not the only one escaping cabin fever: in several locations, I saw very recent tree-cutting and branch-gnawing that had not been there a few days earlier.

On the ground near Moose Lake I found several small wind-broken cottonwood branches, with the upper sides nicely de-barked. Some lucky gnawer had capitalized on this bonanza. But who was it? Not a beaver, although beavers had debarked a cottonwood tree trunk near the lake, leaving the marks of wide incisor teeth. Not a porcupine—the tooth marks were too small. But the marks were too big for a mouse. My best guess was probably a snowshoe hare; hares are generally fairly numerous in the area and the incisor marks were similar in size to the teeth in a hare skull in my collection.

porcupine-midden-pam
Photo by Pam Bergeson

Along the Treadwell Ditch are many trees, usually hemlocks, that show the marks of porcupine gnawing—tooth-marked, barkless patches, low on the trunk. This is a common sight around here, of course. I was particularly interested to find at least two trees that seemed to have been completely girdled sometime in the past. The bark had been removed all the way around the tree, which would interrupt the flow of water and nutrients between roots and crown, starving the roots of food and the crown of water. Yet these trees sported full crowns of needles and looked healthy. How could that be? The porcupines had removed all the outer bark and eaten most of the nutritious inner bark, but a meager, sketchy, brown network of inner bark was still visible. Could it be that enough strands of inner bark remained to connect the roots and the crowns? Hard to believe that would be enough to support a good-sized tree!

There are other little mysteries about porcupines and hemlocks. Some trees have obviously been visited repeatedly, in different years. Old chewings have partially healed, but new ones are there too. Are these trees particularly tasty? Also, I get an impression (untested, so far) that porcupine gnawing is more common on the uphill side of a hemlock trunk. Is that really so, and if so, why?

A special pleasure was seeing two humpback whales spouting as they cruised near Lena Point. They may have been late-departers for winter in Hawaii or they may have been among the few that overwinter here, feeding on herring (and any other luckless little forage fishes). Not on this day, but sometimes one can see a few sea lions swimming near the corners of a foraging whale’s mouth, trying to catch the fish that slipped away from the whale. The herring equivalent of ‘out of the frying pan, into the fire’!