Windfall Lake

The trail to the Windfall Lake cabin is in pretty good shape with some new and improved bridges, and the muddy spots are nowhere near as bad as on some other trails. It was an easy walk in, even with a full backpack loaded for a two-night stay.

Four of us settled in, hoping for the peace and serenity that usually prevails near the lovely lake. “Twas not to be, alas, because there was a nearly constant parade of helicopters overhead, flying back and forth, presumably to the new mine being developed near Herbert Glacier. A boat with a loud jet motor careened around the lake, vanished for a time in the upstream direction, and then eventually roared off downstream.

We had hoped to launch the old canoe that is stored near the cabin, in order to explore the perimeter and the swampy area at the other end of the lake. But, no go. There are numerous holes in the aluminum hull, mostly patched with duct tape. But some patches were loose or gone, and everything was too wet for us to apply new ones. Even the skiff had bullet holes in it!

At least the weather cooperated: the rain stopped whenever we were hiking. We strolled up the trail from the cabin toward the divide that separates the Windfall and Montana creek drainages. This part of the trail was in decent shape, with only a couple of wind-thrown trees and one serious mudhole that required circumnavigation. I hadn’t hiked this part of the trail for a few years, so I was glad we went there. Bears liked that trail too, leaving evidence of their passing: scats full of blueberries and skunk cabbage fibers or devils’ club seeds.

It’s an easy route, winding up the ridge to the divide. Big, glossy deer ferns adorned the edges of the trail, some of the biggest, most vigorous ones we’d ever seen. A happy find was three juvenile toads, less than two inches long, and each with a different color pattern. Toad populations have declined precipitously in recent years, so we are always glad to find some. Cloudberries in the muskegs were quite bleached out and even less tasty than usual.

We found a stand of a little plant that has more names than it really needs: Geocaulon lividum, Comandra livida, northern comandra, pumpkinberry, timberberry, and –more interestingly—northern bastard toadflax. (I really must try to find out the derivation of that epithetic name!) I don’t see this plant very often around here, and I tried but failed to dredge up what I once knew about it from among the dust mice and cobwebs that clutter the remnants of my brain. After I got back home, with a little help from Google, it all came back to me. This plant is another hemiparasite; it has green leaves but its roots also attach to the roots of many other species, including spruce, willow, alder, and aster, so it gets part of its nutrition by stealing it from others (see Juneau Empire August 17, 2012). It also seems to be the alternate host for a blister rust that attacks lodgepole pines, possible including our shore pines.

Geocaulon lividum. Photo by Katherine Hocker

Bird activity was predictably low. Ravens, jays, and a nuthatch were heard behind the cabin. A male kingfisher flew over the lake. A female yellowthroat (I think) gleaned bugs from shoreline vegetation. An eagle swooped low over the water, caught a small fish, and flew up into the forest. Shortly thereafter, the persistent screaming coming from that area stopped short, so we surmised that a juvenile eagle had been yelling for food, and got it.

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The last throes of summer

Early September—and Gold Ridge earned its name in a botanical (rather than a mineral) way; the open slopes were covered with the golden leaves of deer cabbage. Color accents came from the scarlet berries and crimson leaves of dwarf dogwood. There were even a few scattered flowers of about ten species still in bloom, with little hope of pollination, but swathes of partridgefoot, still flowering, clothed a few protected pockets.

Black crowberries and two kinds of low-bush blueberries offered snacks to foraging birds and hikers. The very last salmon berries hid under drooping foliage.

A female grouse and a big chick tried to be invisible at the edge of an alder thicket; their patience outlasted ours, and we eventually went on up the trail. A very small marmot hustled into its burrow with a big mouthful of dry grass for a winter bed, while an adult marmot posed regally on a rock right next to the trail. The marmots will disappear for the winter very soon now.

Swarms of minute insects danced in the open spaces between the canes of salmonberry. I have no idea what they were, but surely they were in reproductive mode, trying to beat the onset of low temperatures.

On another day in early September, a stroll through the lower muskegs at Eaglecrest found some good patches of still-unripe bog cranberries and some low-bush blueberries. We saw that a few of the dwarf dogwood berries had been sampled by some small animal, leaving a hole but without removing the seed—very different from the more usual rodent foraging, which focuses on the seed, leaving a hollow fruit behind. I have to wonder who might eat the dogwood berries; I’ve seldom found the seeds in the hundreds of bird or bear scats that I’ve inspected.

A few swamp gentians were still tightly furled in bud and were probably too late for pollination, as were the one or two bog kalmias that were still open. We searched for sundews and found only three decrepit specimens where earlier there had been thousands, so we concluded that they had gone to bed for the season.

Dragonflies—the big, blue darners, mostly—still cruised the ponds and waterways in search of occasional prey. One enterprising couple flew by in copula: the male clasped the female behind her head with the grasping appendages at the end of his body, and the female looped up her abdomen under the male’s thorax where his sperm are stored. He carried her around while his sperm were being transferred to her ovaries (and perhaps he also displaced or removed sperm from a previous mating!). She would probably lay her eggs in dead wood or vegetation, where they would overwinter.

Meanwhile, the sockeye run in Steep Creek ended, and we await the arrival of the coho. The mallard ducks that visit my home pond are all in brown, eclipse plumage. A few, however, are starting to show rusty chests and darker heads that will turn green as the males don their courtship feathers. Mallards begin their courtship and mate-choice in winter—it seems to be a gradual process.

Cottonwood and devil’s club leaves are turning golden, willows sprinkle their crowns with yellow leaves, and the maples glow with yellows, orange, and several shades of red. Highbush cranberry leaves turn to pink and red, and the wild crabapple leaves get a characteristic shade of rather grubby, rusty red. Even some of the blueberries, especially in the alpine zone, are colorful. The alders get left out of this color show; their leaves turn dull brown and crinkled. Why are they so different?

Amid hundreds of ripening rose hips, I saw a single, lonely pink blossom.

“Tis the last rose of summer

Left blooming alone.

All her lovely companions

Are faded and gone”

Spring?

The days grow longer and we all start wishing that spring would be here NOW! Indeed, spring is slowly, slowly springing. Perhaps it got a bit confused by the lack of a real winter? Or perhaps we are just a tad over-eager.

There are, in fact, a few signs that the new season is upon us. The flocks of varied thrushes that fossicked about on the beach fringes have dispersed, and we now hear the familiar song from many points in the forest, as they set up their breeding territories. Song sparrows are singing, too, a trifle rustily, but soon to be in good voice. Steller’s jays are now seen commonly in pairs, and their calls are more varied than in winter, or so it seems. Hooters (sooty grouse) are heard again on the hillsides. The robins are back, but I have yet to hear their song.

The red-breasted sapsuckers are here, checking out snags and light posts, tapping on trees and houses. Canada geese are busily grubbing up sedges from the wetlands, picking off the sharp, protective tips of the new shoots and biting off the nutritious new growth. Various reports come in: I heard a ruby-crowned kinglet, saw an early hummer, heard a junco sing.

As the ice melts on my home pond, mallards again arrive, drifting in the bit of open water at the outlet, marching across the ice, scavenging spilled bird seed. Even though the millions (apparently) of pine siskins seem to prefer feeding on the massive spruce seed crop and the alder seeds, some of them visit the feeder hanging over the pond and messily select certain sunflower seeds, dropping hundreds onto the pond. Squirrels and mice, as well as the mallards, make good use of the rejects. And, I happily see ‘my’ nuthatches again, after a long seasonal absence.

The most exciting sighting in the bird way was a small flock of rusty blackbirds in the Dredge Lake area. As usual in my limited experience with them, they were poking about in a shallow, brushy pond. But I didn’t get to watch them for long; they soon moved deeper into the thickets. I don’t see them very often as they migrate through here to the north country. Unfortunately, their population has declined dramatically in recent decades, for unknown reasons, so they are getting harder and harder to see.

Female rusty blackbird. Photo by Bob Armstrong

The plant world, too, is showing feeble signs of spring. Elderberry buds grow fat and shoots of cow parsnip peek up above the leaf litter. In some places, felt-leaf willow has borne fuzzy catkins for a week or two already. Blueberry shoots are ready to go, just waiting for the right moment. The first shoots of skunk cabbage to emerge from the muck were eagerly cropped by deer.

Mountain goats are back on the ledges near Nugget Falls. Beavers never really quit working this ‘winter’ but got busy every time the temperatures rose and the ice weakened. Bears, probably especially juveniles or males, have begun to emerge from winter dens: moms with cubs presumably wait somewhat longer, so the new cubs are strong enough to follow mom around the forest.

I can’t claim that spring has sprung, but it may be creeping up on us, all the same!

Sheep Creek Valley

I go up into Sheep Creek Valley several times a year; it’s one of my favorite places in Juneau. I was there in mid November with Parks and Rec hikers, and we spotted several things of interest. It had snowed recently, so tracking was good. We found tracks of squirrel, deer, mountain goat, a possible weasel, a large canid that could have been a wolf or just a big dog, and lots of porcupine tracks. Two porcupines scuttled off into the brush as we walked by.

A big conifer tree had a large squirrel midden around its base; discarded cone scales and cores covered many square yards. The main cache of full cones was underground, but this red squirrel was not content with that—it had also wedged cones into every available space between the roots and in grooves of the trunk.

We found a beautiful orange and yellow fungus growing on a dead branch. It is a type of jelly fungus, possibly the one called “witches’ butter”.

Some of the more enterprising hikers went up the slope at the back of the valley, far enough that they were wading in thigh-deep snow. Other, less energetic perhaps, were content to perch at streamside for a relaxed lunch break. The creek was running crystal clear and wide open, so we had hopes that a dipper might show up. Indeed, one did, prospecting for aquatic insects along the edge of the water and moving quickly upstream.

Sheep Creek Valley is among the first places I worked when I came to Juneau over twenty years ago. My first big project was to census nesting birds in various habitats; there seemed to be no previous studies of breeding bird communities that would provide an estimate of avian diversity and abundance in different habitats around here—very basic information for future ecological studies.

So for several years, in spring and summer, my field techs and I studied bird communities in Sheep Creek Valley and elsewhere in Juneau. We counted birds, using a standard protocol, by sight and by songs and calls. We found that this valley has a very rich community of nesting birds, arguably the richest one in our area. For example, we counted several kinds of warblers, sparrows, and thrushes—more kinds than in the spruce-hemlock forest.

Along with the standard censuses by sight and sound, we regularly mist-netted birds in the understory. Our black nylon nests were twelve meters long, and we would set up an array of about ten nets in various places. Then we’d walk the array of nets every hour or so, extract and weigh the birds, and release them. Among other things, the net captures helped us detect birds that were quiet and secretive.

There were a few bears in the valley. Occasionally, we would glance up as we extracted a bird from a net and see a calm bear sitting near the end of the net and observing all of our actions! They didn’t seem to have designs on us or on the birds; apparently they were simply curious.

Our other main activity was nest-searching. This is hard work and lots of fun, rather like a continual treasure hunt. By following a bird for a while, often on several occasions, eventually one deduces the approximate nest location, and then careful searching reveals a nest. It often takes several hours of detective work, perhaps over several days, to locate a nest this way. Once a nest was found, we monitored its progress, from incubation of eggs to care of nestlings to fledging—or until the nest failed. Then, for each species, we could calculate the percentage of nests that successfully produced young. For example, about sixty-five percent of yellow warbler nests were successful but only about thirty percent of robin nests and roughly twenty-five percent of fox sparrow nests were successful.

A principal cause of nest failure was predation on eggs or chicks. By installing small cameras that were triggered by removal of an egg, for instance, we learned that predators include Steller’s Jays, red squirrels, mice, and even shrews (see accompanying photo). But Sheep Creek had fewer egg and chick predators than conifer forest.

All of that work required us to begin at dawn, because bird activity is generally greatest early in the morning. The days are wonderfully long in spring and summer, so that meant we started work by three-thirty or so (and had to get up around two a.m., to get to the study sites; this was not so wonderful!). Nevertheless, I look back on those days with much pleasure (perhaps especially because I no longer have to crawl out of bed at crazy hours).

Pollination tricks

Flowers are a plant’s way of sexual advertisement. They are evolutionarily designed to attract animals that visit the flower in hopes of collecting nectar or pollen to eat, inadvertently accomplishing pollination. Insects are the most common type of animal that provide this service for flowers, although some insect visitors are thieves, taking the food but without pollinating.

To accomplish pollination, the foraging insect, as it rummages around inside a flower, incidentally gets pollen on its head or body or legs from the male parts (called anthers) of a flower and accidentally brushes off the acquired pollen on a receptive surface (called a stigma) of the female part of a flower. Many flowers have the means of avoiding self-pollination (within the same flower or between flowers on the same plant) and promoting cross-pollination from another plant, which creates greater genetic variation among offspring, one of the chief advantages of sexual reproduction. But that’s another, long story, so here I’m focused just on some behavioral interactions of insects and flowers.

Flowers have evolved many ways of controlling the visits of their pollinators, so the insects enter the flower in a particular way that effectively removes pollen from the anthers and deposits pollen on a stigma. The variety of ways in which plants do this could be the subject of several books; indeed, Darwin wrote one just about The Various Contrivances by which Orchids are Fertilised by Insects.

I’m not about to write a whole book here, so I’ll just describe a few ways some of our local flowering plants accomplish pollination. Open, saucer-shaped flowers are available to most insect visitors. A rose, for example, produces anthers and stigmas right in the middle of a circlet of petals, and all an insect has to do is walk around in the middle of the flower, sipping nectar and casually picking up or depositing pollen when it happens to contact the anthers. Nothing to it! Almost any bug can do it.

Much more interesting and intricate mechanisms of pollination exist in our local flora. For example, twayblade orchids grow profusely in young conifer forests, such as in Gustavus or near Eagle Glacier cabin. The flowers are tiny, pollinated by very small bees and flies. When the insect seeks nectar, it triggers the explosion of a drop of sticky stuff that picks up pollen on its way out of the flower and sticks the pollen to the head or eye of the insect, where it is cemented. Some parts of the flower actually move apart in order to make space for the exploding drop and pollen to emerge and fasten to the insect. Later, when the insect visits another twayblade, the pollen is detached somehow and deposited on the stigma, sometimes leaving the congealed sticky blob behind on the insect. Darwin spent a lot of effort figuring this one out!

A very different pollination mechanism is used by lupines, which are pollinated by bees. The sexual parts are hidden away in a fold between two fused petals in the lowest part of the flower. A bee pries open the fold as it probes for nectar. When it does so, out pop the sexual parts, and pollen can be dusted on the bee or brushed off the bee onto the stigma. When the flower has been visited, the uppermost petal has turned from white to pinkish-purple. The color change is a signal to future bee visitors that the nectar is depleted and the bee should visit other flowers on the stem.

Louseworts, in contrast, hide the sexual parts in a little hood in the upper part of the flower. So a visiting bee has to get into the flower in a certain way, often wedging open the hood, in order for its body to contact anther or stigma. One of the louseworts in Southeast, however, does it differently, as described the next paragraph.

“Buzz pollination’ is one of the most interesting and common pollination mechanisms in our area. In this process, a bee (usually) lands on the flower and buzzes in a special way. Its major wing muscles are temporarily inactivated, and its body just vibrates very rapidly, repeatedly hitting part of the flower. The vibrations shake dusty pollen onto the bee’s body, to be deposited eventually on a stigma. (Obviously, this technique doesn’t work with sticky pollen). Buzz pollination is how shooting stars, tomatoes, blueberries, wintergreens, and many other flowers get pollinated. Buzzing may also contribute to pollination even in open, saucer-shaped flowers such as salmonberry and roses.

Bog laurel. Photo by Bob Armstrong

Bog laurels grace our muskegs with their pink, wide-open flowers. If you look closely at a young flower, you would see that the female parts are in the center. But the male parts consist of arched, white filaments leading from the flower center to small, dark blobs (the anthers) that are nestled in pockets on the surface of the petals. When a bee lands on the flower, the spring-loaded filaments straighten, raising the anthers, and shaking pollen on the buzzing bee. So you can tell if a bee has been there by looking at the position of the filaments (arched or straight) and seeing if dark anthers remain in the petal pockets.

 

I’m sure there are other cute tricks by which our local plants contrive to deliver pollen from flower to flower. See if you can find some!

Otters

A week or two ago, I enjoyed watching a young otter, grooming and snacking, on the banks of my home pond. The next morning, when I peered out my windows, it was clear that the otter had come back, leaving a furrow in the snow, across the frozen pond, under my front-entry deck, and around the house. A few days later, it was back, scouting around the house and garden and checking out the pond, leaving a new furrow in the snow. Perhaps it has a regular (but temporary) route it follows, revisiting places where foraging has been successful in the past.

I’m guessing that this individual is a member of the family we often saw in the Dredge Lake area last fall. There were four big offspring with their mother. The young ones often stay with their mother into the winter and then disperse to live on their own. Dispersal distances are sometimes quite long, averaging almost forty miles for females in one Alaskan population (and slightly less for males).

Photo by Jos Bakker

Young otters continue to grow for several years, although they are said to be sexually mature when two years old. But males may not be “accomplished breeders” until they are five to seven years old, according to the literature. Mating usually occurs in spring in Alaska, but otters, like other members of the weasel family, have delayed implantation of the embryo. This means that the early embryo floats around in the female’s uterus for many months in a state of arrested development. Eventually, the embryo attaches to the uterus; active development begins and takes about two months.

The otters I’ve seen here in Southeast have been solitary or clearly a family group of mother and offspring. So I was very surprised to read that otters can be highly social. Males sometimes form long-term groups that forage together, perhaps breaking up in the breeding season when males go looking for mates, but then re-gathering for the rest of the year, and even staying together for several years. Nonbreeding females may join such groups. Occasionally a weaned offspring delays dispersal, staying home and helping the mother with the next litter.

As I skied around in the Dredge Lake area recently, I saw a long, brown shape poking around under the edge of the ice near a patch of open water. The otter emerged and foraged in the shallows until it noticed me, standing stock still on the trail. Then it bolted upstream. A bit later, I found a nice otter trail over the ice of one of the ponds, going out to a small area of running water and coming back toward the river. Hungry otters often cruise widely in their search for edibles. Almost any kind of meat is fair game for otters; although their mainstay is fish, they also eat mollusks, crabs, worms, frogs, and even occasional birds and small mammals.

Although their official common name is ‘river otter’, some folks call them ‘land otters’, perhaps to distinguish them from sea otters. Both common names are a bit misleading, because the versatile ‘river otters’ forage not only in rivers and streams but also on land and in the ocean. We often see them on rocky beaches when we are kayaking. I once watched an otter diving repeatedly down to a submerged bar between two islands; this was a banquet in salt water, apparently, because the otter brought up something edible on almost every dive.

Monkshood flowers

One warm but very windy day, a friend and I were perched on top of Gold Ridge in a small swale that provided some shelter from the wind. The alpine meadow was dotted with the purple flowers of monkshood. I had forgotten the structure of monkshood flowers, so I spent a few minutes opening one and examining the arrangement of parts inside.

The structure is really quite odd—very different from most other flowers in our area—although there are dozens of other species of monkshood (genus Aconitum) elsewhere in the world, which suggests that this odd structure is one that works well. Monkshood flowers are considered to be pollinated chiefly by bumblebees, although other animals may also visit the flowers occasionally. As I examined my specimen flower, it occurred to me that perhaps it would be interesting to learn how bumblebees visit and exploit the nectar while (potentially) depositing or exporting pollen.

Monkshood flowers are slightly complex, requiring a visiting bee to enter and move in a particular way. Most bumblebee species are generalists, capable of exploiting several kinds of flower. Naïve, inexperienced bees have no trouble figuring out simple, open flowers such as those of buttercups or roses, but they have to learn how to exploit more complicated flowers such as lupine or monkshood, and it may take a number of tries before the bee succeeds in getting to the nectar—indeed, these failed foragers often just give up. One species of bumblebee is considered to be a specialist on monkshood (elsewhere) and this species has a very short learning period, quickly getting to the nectar.

To explain what a bee has to do in a monkshood flower, I first need to describe a typical monkshood flower so an interested reader can then visualize a bee’s activity. In most other flowers, there are colorful petals that are backed by protective green sepals, but in monkshood, the purple exterior of the flower is composed of sepals that have been transformed to function like petals. There are two small sepals at the lower edge of the flower and two large, lateral sepals. Most conspicuously, there is a large, expanded sepal that forms a hood on the top of the flower (botanists perversely call this a ‘helmet’). The hood is reminiscent of the cowl of a medieval monk—hence the common name.

Photo by Bob Armstrong

Inside the flower, at the base of the sepals, lie the working parts: lots of short stamens offering pollen in their anthers, to be picked up and exported by a flower visitor (male function) surrounding a few stubby pistils that will become fruits if pollen is deposited on their receptive stigmas (female function). Inside the expanded hood lie two true, narrow petals that bear nectaries tucked way up into the top of the hood. To get to the nectar, a bumblebee has to reach or crawl inside the flower, passing over the sexual parts as it does so, picking up or depositing pollen.

As is so often the case, our local species of Aconitum (A. delphiniifolium) has not been studied, so research on other monkshood species may be used to shed light on the local species.

Japanese researchers experimented with the flowers of their monkshood species: they removed one or more sepals and watched the behavior of bumbles on the manipulated flowers, recording the amount of pollen picked up and deposited by the visiting bees. Removal of the large lateral sepals deprived a bee of her usual platform for standing in the flower while she reached up to the nectaries. This meant that her body did not contact the anthers or stigma properly, so pollen pick-up and deposition (and fruit set) was reduced. Removal of the small lower sepals had little effect except that a bee had some trouble entering the flower. Taking off the hood of the flower changed the look of the flower greatly, but bees still visited. However, sometimes the bee extended her tongue into the air instead of inserting it into the nectary, so although the pollination effectiveness of the visit was adequate, the bee often got no reward—and that would mean that the rewardless bees would be less likely to visit other such flowers. The researchers suggest that the function of the hood is to guide a bee’s tongue to the nectaries and perhaps also to maintain the concentration of sugars therein, thus keeping the bees’ interest in visiting.

In at least some species of monkshood, there is considerable variation among populations in the depth of the nectary and hence in the distance a bee has to reach in order to get nectar. A long nectary can only be reached by a long-tongued bumblebee species; short-tongued bumblebees have trouble reaching the nectar in the normal way and may become nectar-robbers, by chewing a hole in the hood and reaching into the nectary that way. Nectar robbing may reduce visits by good pollinators and has the potential to reduce both pollen export and deposition.

Herbivores and their plants

When herbivores consume their food plants, sometimes they just nibble a bit and there is little impact on the plant or on the consumer. Aside from that trivial outcome, there are two possibilities. One: the herbivore consumes so much plant material that the remaining plants are very badly damaged (think of overgrazed pastures, for instance) or are stimulated to produce defensive chemicals that deter further consumption. For example, browsing by snowshoe hares induces the production of chemical defenses in feltleaf willows, and the hares then eat less of plants with increased defenses. In both cases, the food supply for consumers is markedly reduced.

The second possible outcome is that consumption by the herbivore increases the future supply of the food resource. This sounds crazy—how could damage to the plants increase the resource and ultimately benefit later consumers? It is not entirely crazy; in certain circumstances, it has been documented to happen.

The classic example comes from studies of the grazing herds of the Serengeti in Africa. As the herds move across the plains, they crop the grasses. This stimulates the grasses to grow (in order to produce seeds eventually), helped along by fertilization from the animals’ waste products. So when the next bunch of grazers passes by, the supply of grasses has recovered and even improved. A similar effect is achieved when humans mow their lawns. Ecologists call this an increase of primary productivity, because the basic producers of energy and nutrients for the food web (namely, the plants) have increased. This kind of response to grazing can happen when the system is rich enough to support the continued growth of the plants; it doesn’t work in nutrient-poor or water-limited systems.

A neat example of herbivore-induced increase of resources comes from an Arizona study of the effects of a stem-galling sawfly that parasitizes arroyo willows; the gall is produced by the plant in response to the irritation by the sawfly. Female sawflies insert their eggs into young shoots and the larva feeds on the resulting gall tissue. When there is little egg-laying by sawflies, the willow branches naturally become more resistant to galling as they age. However, when galling is heavy, something else happens. Heavy galling kills the end of the shoot, and this allows sprouting of dormant buds near the base of the shoot. These buds make new, young shoots that are susceptible to the galling action of the sawflies. In effect, severe galling activity can thus renew and increase the food supply for later sawfly larvae (and anyone else that likes young willow shoots).

Closer to home, the browsing of ptarmigan (and moose) on feltleaf willows in northern Alaska affects the growth patterns of the willows: removal of the terminal buds and shoots kills the twig and allows the buds and shoots lower on the branch to sprout. The new shoots are more numerous and have more buds on browsed branches than unbrowsed shoots. Repeated browsing produces a ‘broom’ architecture and eventually reduces the height of the willow shrub. Thus, not only are there more shoots with more buds for ptarmigan to eat, but also the buds on shorter shrubs are just at a height where ptarmigan like to forage. So the bud supply for ptarmigan in the future is increased. However, the effect on the willows is negative—production of flowers and seeds is much reduced.

The take-home lesson is that the interactions between the eater and the eaten are not necessarily simple! The plants are not merely inert victims of munching animals. A close look is needed to understand what is going on and then explore the ramifying consequences.

Early July scrapbook

The holiday week in early July found me on several short excursions. A trip to Lurvey Falls near the end of the Perseverance Trail was particularly rewarding for an old dipper-watcher and companions. As we approached one of the wooden bridges in the upper basin, we noticed a young dipper perched on the edge of the planks. So we stopped and ‘froze.’ Pretty soon the juvenile was pecking at the surface of the boards, poking down in the cracks between the boards, and being quite successful at finding little edibles—and discarding a few inedibles. It foraged this way for some minutes.

Then it hopped up on the bridge railing, picking up tiny things as it moved along. Gradually, it got closer and closer to us, until it was right next to me, just below my hand—and it nabbed a bug off my jacket before leisurely hopping back along the railing. What fun!

We think we found its parents a little way upstream, carrying beakfuls of bugs in both directions, up and down the creek. They appeared to have fledglings scattered all along the creek, and our insouciant juvenile was probably one of them.

A walk on the wetland at the end of Industrial Boulevard brought me into ‘sparrow-city.’ Song sparrows lived in the very brushy zone of alders and willows. As the thickets became sparse and mixed with grasses and herbs, I found a few Lincoln’s sparrows. Out in the open meadows, there were dozens of savanna sparrows, some singing and others with beaks full of green caterpillars and long-legged crane flies for their chicks.

Nest boxes on stakes were occupied by tree swallows. As I walked on the trail past one box, an agitated adult swallow dove close to me head repeatedly, until I moved along a sufficient distance from its nest. Another box seemed to have produced some fledglings that did not venture very far away and were actively tended by busy adults.

Tree swallow on nest box. Photo by Katherine Hocker

Some of the old, upturned snags and stumps scattered around the meadow are pieces of sculpture, if you take time to look. Beautifully curved roots, almost muscular-looking, once held those trees in the ground. Now they support mosses and lichens, and lots of tiny red mites.

My home pond has hosted at least three broods of mallards, all of different ages. Only two juveniles were left in the oldest brood, now almost as big as mom, with bodies well-feathered but wings still too short for flight. Five downy, middle-sized ducklings were just getting real feathers. And a brood of seven tiny fluff-balls arrived with their very vigilant mother. On most days, only one family used the pond at a given time, and if there was a brief temporal overlap, the females kept the broods well apart.

As usual, visits to the glacier area provided entertainment. The terns had gone, but barn swallows were nesting in the pavilion and exercising mosquito control in long, graceful swoops. A brood of mergansers rested, with mom, on a rock. A downy Barrow’s goldeneye duckling foraged alone for days, no family in sight, but apparently doing well for itself. A myrtle warbler (a.k.a. yellow-rumped warbler, a.k.a. butter-butt) flitted along the roof edge of the pavilion, gleaning insects. One aerobatic warbler chased flying insects high above the pond made (but no longer occupied) by beavers; it flew so high that it was just an animated black spot, diving, circling, climbing, and looping.

An adult black bear had climbed to the very top of a cottonwood tree. There it chewed through several inches of wood, causing the tip of the tree’s trunk to fall. The bear caught the falling piece and promptly ate the seed pods. Then it moved down to a sizable side branch. Planting its rump firmly in the junction of branch and trunk, it started to chew off the branch. Deciding, apparently, that this part of the branch was too thick, it reached out another foot or so, and chewed again, but briefly. Again, not satisfactory. So, stretching out as slender as a big bear can get, and balancing well along the branch, it gnawed through the branch at a thinner place, brought it down, and again gobbled up the seed pods. The top of the tree was a wreck, and the bear slid down and wandered off into the woods. Watching the antics of bears in the trees can be as much fun as watching them in the creek later in the season when the fish arrive.

Canada geese

A favorite sign of spring is a flight of Canada geese, winging northward in the familiar V- formation, talking to each other as they go. I hear them coming, tip my head back, and wait—and then there they come. Gradually the melodic calls fade away in the distance. There’s nothing quite like it!

A migrating flock of Canadas is a very familiar sight for many people. So perhaps it is not very surprising to hear someone say, as we are driving down Egan over Lemon Creek, “Oh look, the geese are back!!” But the geese seen there and elsewhere on the wetlands in winter and early spring are not migrants. They can be found somewhere on the wetlands at any time during the winter; an estimated five or six hundred Canadas spend the winter with us.

Vancouver Canada Geese in flight. Photo by Bob Armstrong

These geese belong to a coastal subspecies, whose geographic range roughly coincides with the coastal rainforest. They are considered to be non-migratory, although these birds may make short-distance movements at certain seasons.

Of course, we have some migratory Canadas too, in season. One subspecies nests chiefly on the Copper River Delta, and passes through here, to and from its wintering grounds a little farther south. Another subspecies nests in the Interior, and part of that population winters in California, coming by us in spring and fall. In addition, there is the small Cackling Goose, which looks like a miniature Canada Goose but is now considered to be a different species; it can occasionally be seen here as it flies between western Alaska and California.

The entire species we know as Canada goose is widespread in North America. It is divided into several (or many, according to some researchers) subspecies. The birds of some subspecies are very large; for example the one that uses the Mississippi flyway averages maybe 4500g (almost ten pounds). The Cackling Goose is quite small, averaging roughly 1600g. Our resident birds, known as the Vancouver Canada goose, are intermediate in size, averaging over 3000g.

The Vancouver Canada geese nest in rather dense rainforest, unlike most other subspecies, which typically use open habitats near water. Vancouver Canadas usually place their nests on the ground (as do other subspecies), but sometimes the nests are on snags or in trees, as much as 15 m above the ground. Some nests are in muskegs, and many nests are relatively close to muskegs and small pools of standing water. Nests are not necessarily close to ponds or lakes.

Male and female form a long-term pair bond, spending their lives together. During the month-long incubation period, when the female is incubating, the male commonly perches high in nearby trees, standing guard. Clutch sizes vary greatly, but often there are three to five eggs; older females usually lay larger clutches and larger eggs than young females.

Broods of Vancouver Canada geese use dense understory as escape habitat when threatened by potential predators. This is quite different from other subspecies, whose nests are commonly close to water and whose broods typically flee to open water. As the rainforest goslings grow, they are found more often in open habitats, not necessarily near the nest site. They often band together with other broods in crèches, which are thought to reduce the risk of aerial predation. Young birds stay with their parents though the winter.

Nest success can vary enormously, depending on weather and predator activity. For the rainforest subspecies, and for the species as a whole, as few as 25% of nests may be successful in producing goslings, but in good conditions, sometimes over 80% of nests are successful. Cold, wet weather is deleterious to nest success, and areas with many predators (for example, foxes, coyotes, ravens, mink, bears) may lose most of the nests. The age of the female also matters: older females are generally more successful than younger ones.

Although the geese may mature at an age of two years, some do not mature until they are three years old. If they are lucky, they may reproduce for several years.

After the nesting season, in late summer, Canada Geese molt their worn flight feathers, so for three or four weeks they cannot fly. In preparation for molting, Vancouvers typically move relatively short distances to selected, protected bays and inlets, where foraging is good. There they grow their new flight feathers in relative peace. Wachusett Inlet in Glacier Bay is one of molting sites; if you kayak into this inlet just after molting time, the water surface is covered with goose feathers.

Canada Geese are herbivores, grazing on many kinds of plants in the course of a year. The Vancouver Canada Goose likes skunk cabbage leaves in the nesting season; one can often see the bite marks on the standing leaves. They also eat blueberries, lingonberries, and crowberries in season. In late winter and early spring, the Vancouvers often forage on the roots and young shoots of sedges in the wetland. Most goose foods are not highly digestible or high quality, and the digestive processes of geese are reported to be moderately inefficient, so geese need to eat a lot. There are reports that they may sometimes snack on small clams and worms, drifting salmon eggs, and even dead salmon.

The need to eat large quantities of vegetation means that geese spend a lot of time just eating. A group of foraging geese usually has one or two individuals standing upright, as sentinels, to warn of approaching danger. If wandering people or dogs come too close, the flock will take off and seek a less disturbed foraging area. Flight is expensive, and the more the birds are disturbed, the more food they need to pay the costs of flight. So frequent disturbance makes it hard for them to get enough food.

During the hunting season on the Mendenhall Wetlands, geese become very wary and easily disturbed. In fact, observers have noticed that geese (and ducks) often leave the wetlands during the day and fly to Auke Lake, in order to avoid the hunters. They come back to the wetlands at night to forage. Unfortunately, these daily flights cross the paths of approaching airplanes—not good for either goose or plane!