Strolling on the snow

Snow and more snow!

The deep snows this winter are too much for these little snowshoes we usually use here—one just postholes, and the enlarged feet have a hard time pulling up out of the hole. The old North Woods style of ‘shoe would be more suitable. But the little ‘shoes are what we have, so we tend to stick to the groomed trails, walking on the side of the trail as much as possible and avoiding disturbance of the classic tracks set by the groomer.

One day in late December, a friend and I strolled up Montana Creek, looking for signs of wildlife activity. But nary a track could be seen. Strange. Some distance up the trail, a bit of open water appeared, just a very narrow, intermittent channel. Friend wished for a dipper—and just on cue, one came around a curve, flitting downstream. It stopped briefly in each small opening in the ice but didn’t seem to find much to eat and eventually went farther downstream. But there wouldn’t be any open water there until it reached the Mendenhall River, so its explorations would have to continue. When streams are frozen, dippers often forage in intertidal zones.

The next week, we rambled around the Lower Loop at Eaglecrest, where critter-tracking is often rewarding. This day was no exception: there were weasel and porcupine trackways ranging widely; voles and shrews had scampered in and out of sheltered spots. Snowshoe hares had explored many places, usually under brush or low-hanging conifer branches, where the snow was not so deep.

There was not much sign of squirrel activity, just a few tramplings near some trees. I wonder if they were using tunnel systems under the deep snow—the squirrel that lives near my house seems to have long, well-used tunnels, which it often uses instead of traveling on the surface, popping up near what used to be a garden. I know that voles and shrews often scurry about below the snow, but they had appeared on the surface fairly commonly. So why not the squirrels– perhaps they weresnacking on things in their snow-buried middens??

Ptarmigan or grouse left their bipedal trackways, often in and around brushy thickets; they may have nibbled blueberry buds as they walked. One of these birds came up to a steep little bank on the edge of the trail and slid on its bum down the loose snow, to find its feet again at the bottom of the short slope.

I spent quite a lot of time in a spot where tracks were overlapping and complicated to sort out. Some were from hares, some from ptarmigan/grouse, but there were others also. Only a few of these others were clear enough to allow possible ID: maybe about an inch and a half wide, with five toes, one of them set back a little from the others.  Hmmm, quite possibly a marten! There was, however, no evidence of predation, so I can’t finish the story.

One critter that commonly leaves tracks near the Loop was missing from the records in the snow on this day: Deer tracks were conspicuous for their absence.

I was interested to see that the lower-most extension of the Loop, near the opening of the Treadwell Ditch trail, showed almost no sign of wildlife activity (just one vole track). I’d noticed this lack on other excursions up there. I have to wonder why so little activity is recorded there—the habitat is the same (to human eyes), so why is this part of the Loop apparently so un-used?

In early January, we walked up the Dan Moller trail, using the convenient snow-machine route, which was packed enough to walk without ‘shoes. Up through the meadows, looking for critter signs, but with little luck. The deep snow transformed the once-familiar landscape into unrecognizable terrain. A little imagination added to the fun; the heavy snows had laden the trees and stumps into wonderful shapes. One that caught my eye immediately was clearly an old woman, draped in her shawl, stooped over while mourning a dead companion at her feet.  Another was a small spruce whose top bore such a load of well-packed snow that it was bent into a full-curl ram’s horn. 

There’s no end to what you might find, if you go stravaiging around on our trails!

Birds underwater

a variety of avian submersion strategies

Many kinds of bird regularly forage for prey underwater. These birds have a variety of ways of doing so and adaptations to match. Life in the water is very different from life in the air.

The first hurdle to overcome is simply getting there. Some species start from the water surface. A few are able to just sink below the surface by decreasing their buoyancy: small grebes and anhingas do this by compressing the plumage (thus pushing air out) and exhaling. Others tuck their heads and kick with their webbed or lobed feet (e.g., mergansers, goldeneyes, buffleheads, most cormorants, loons, and some grebes) or flip their wings (murres, long-tailed ducks, dippers). Those that surface-dive a lot (e.g., loons) typically have legs set well back on the body, making them awkward on land. 

Another way to get underwater is from above the surface.Dippers often dive into a stream from a rock or low-hanging branches not far from the water surface. Kingfishers may plungefrom several meters above the surface, folding the wings closer to the sides. Brown pelicans can dive from a height of twenty meters, extending the neck and angling the wings back, making a more streamlined shape. The grand champion divers may be seabirds called gannets and boobies; they can start a dive from almost a hundred meters up, turning the body into a sleek dart, with the neck well-extended and the wings held back close to the body. The dives can reach a speed of sixty mph; to protect the bird from the resulting high impact, the skull is reinforced and subcutaneous air sacs on the chest and sides cushion the jolt.(https://vimeo.com/319325491. By Bob Armstrong, in Loreto, Mexico.)

Belted kingfisher diving and rising with fish. Photo by Bob Armstrong

Most of these dives are quite shallow, but some species are adapted for deeper ventures, with heavier, stronger bones than other birds, to resist water pressure and decrease floatation. Gannets are quite deep divers, sometimes going on down to twenty meters. Loons may dive as deep as seventy-five meters and some of the murres and their relatives go down over a hundred meters; the common murre is said to be the deepest diver (sometimes down to 180 meters) in Alaska. Penguins often launch from ice-ledges; small ones make fairly shallow dives, but the emperor penguin can dive down more than five hundred meters!

The second hurdle to underwater foraging is locomotion in a medium that is denser than air. Most aquatic birds have webbed feet, often set far back on the body for good propulsion and steering; grebes have broadly lobed toes instead. But fancy feet are not always sufficient—some of these birds use their wings to swim in pursuit of prey. Gannets and cormorants can wing-it underwater; murres and puffins have narrow, stiff wings adapted to underwater ‘flight’ (without forsaking aerial flight); penguins swim with their flipper-like wings (and cannot fly) and steer with their webbed feet (some of them are very fast swimmers, clocked at over twenty mph).

Murre underwater. Photo by Bob Armstrong

Kingfishers and dippers don’t have webbed feet, so they have their own ways of moving in water. Kingfishers seem to rise buoyantly to the surface after a dive, wing-fluttering as they lift back into the air. Dippers have strong toes for clinging to rocks and walking even in fast currents, and they swim with their wings for short distances in pursuit of prey; they are the only songbird known to do so and do not have the same adaptions of bones and wings as other, more aquatic, birds do.

Plumages of birds that forage underwater are generally dense and well-waterproofed with oils from the preen gland. Penguinplumage has unusually many tiny filaments that hold air bubbles; when the bird swims, the bubbles are released, which decreases the density of water around the body, allowing faster swimming. Birds that decrease buoyancy by compressing the feathers might get a little of this effect, but penguin plumage can hold more bubbles and release them more gradually.

Diving birds hold their breath underwater, storing oxygen in their lungs. But they can also store extra oxygen in their muscles, in a compound called myoglobin–which, like hemoglobin, is a specialized protein with iron-containing compounds that hold oxygen. Species that engage in long dives and underwater pursuits have more myoglobin than those that spend shorter times without access to air. Emperor penguins can stay underwater for twelve minutes or more (for comparison, humans can normally manage to hold breath for less than two minutes).

Fall Colors

delights of a fading season

Photo by Mary Willson

Here in a rainforest, we don’t get the flamboyant displays of golden-leaved aspens or the flame-colored maples, although there may be some isolated cases of such brilliance dotted about our city streets. Our alpine zones are sometimes full of glorious color, but not all of us can get there. But we do love color. However, think not that we are deprived of these season visions; we have plenty of fall colors. They’re usually somewhat more subtle and on a smaller scale, but quite wonderful in their own way, when we bother to look. Attentiveness, as Robin Wall Kimmerer noted, is the key to seeing.

Here are a few examples of enjoyable displays of fall colors we’ve seen recently:

–on a hummock in a muskeg, a mat of sphagnum moss had turned partly red, still spangled with spots of gold and green. The mat was decorated with crimson leaves of cloudberry, a cluster of scarlet bunchberries, and bunchberry leaves in scarlet and green.

–the last stands of fireweed can be pink or red, or sometimes both of those colors grading into oranges and yellows and remnants of green.

–subalpine slopes are clothed in deer cabbage, offering a mosaic of yellow, golds, russets, and rich browns.

–high-bush cranberry shrubs often sport many colors—the whole bush may bear gorgeous red leaves. On others, each leaf can display every shade of red, orange, and yellow. Sometimes the whole show is high-lighted by those lovely red berries.

–the understory of the dark conifer forest is brightened by the broad, yellow leaves of devils club, even as they become dilapidated.

–cottonwood leaves often turn bronze or gold and flutter nicely in a breeze. How sad that the whole row of shapely young cottonwoods along Vanderbilt Hill Road has been destroyed.

–along one trail, I found a single salmonberry cane with every leaf a color-treat. An occasional leafy stem of goats-beard may be very red in the midst of others that are still green.

–in the forest edges, the heart-shaped leaves of mayflower turn yellow—or sometimes an unusual pattern of white with black lines.

–sometimes a single leaf displays a variety of color 

–and have you ever noticed that the upper sides of silverweed leaves can grade nicely from orange to yellows to tawny browns?

Summer leaves are green, because the cells contain lots of green chlorophyll that does the work of photosynthesis (making sugars). As days shorten and nights grow longer and cooler, chlorophyll gradually breaks down, exposing the yellow carotenoids that have been there all summer (absorbing light energy and transferring it to chlorophyll), concealed by the green. During those shortening days, some photosynthesis continues, but each leaf is gradually disconnected from the rest of the plant, so sugars are poorly transported to the rest of the plant and build up in the leaves. In bright light, they are built into colorful red-to-purple anthocyanins. A single leaf may sometimes be red on one half and yellow on the other, if one half was exposed to sunlight and the other was shaded.

That simplified explanation leaves many questions. Why build anthocyanins in a dying leaf?  Why do some species often produce lots of red leaves in fall, while other usually bear yellow leaves? Why do some of the typically yellow-leaved plants occasionally make red or orange leaves? Why do alder leaves just turn brown, with no bright colors? Readers can probably think of still more questions!

In any case, there is lots of color to enjoy, even in the rain.

Autumn Begins

bears digging, some unusual flowers, and a lovely purple mushroom

On yet another gray, wet day, some friends went up the Eaglecrest Road in early September, frequently stepping off the road to make way for big equipment. Some headed for the Nest, while I and some others searched for the rare white-petalled variety of dwarf fireweed (a.k.a. river beauty). Sadly, it was done flowering—as was almost everything else. There were a few laggard monkshoods, yellow rattle-box, and groundsels, and I saw some delayed salmonberries just ripening. Deer cabbage leaves shone with yellows and golds. It was really autumn at Eaglecrest.

White fireweed. Photo by Kerry Howard

I was interested to hear reports of a Clark’s nutcracker in the area, and there were several bird-watchers on the road, hoping to spot it for themselves. This bird is normally found in montane conifer forests from central BC southward, but I’m told it occasionally ranges north to the southern Yukon and is very rarely seen in our coastal conifers.

Marsh felwort. Photo by David Bergeson

Looking back to our so-called summer: a trip to Crow Point and the Boy Scout beach in mid-August found the little gentian called marsh felwort in its usual place near the trail on flat, gravelly soils. Five pointed petals make bluish or lavender stars that usually appear in August. This little annual plant occurs widely in the northern hemisphere. In the spruce groves there were fairy rings of white mushrooms and a clump of giant purple mushrooms known as purple (or violet) corts. Corts belong to a multi-species complex in the genus Cortinarius and form mycorrhizal associations with the roots of spruces and other trees. Also, around one big spruce tree, I saw a palatial squirrel midden with numerous entrances, one of the most impressive middens I’ve even seen. A lot of spruce cones were demolished to make a pile that size.

Photo by Jennifer Shapland

Both brown and black bears frequent these meadows, and I recently saw tracks of both species. We often see bear diggings here. Usually the bears have been digging roots of Angelica lucida (‘seawatch’), occasionally also eating the lower stems and leaf stalks. But this time, there was one area where bears had concentrated on digging up beach lovage; dozens of holes were marked by the discarded reddish leaf stalks. When the roots of these perennial plants are eaten, presumably the population of those species is reduced, thus reducing their future availability as bear food—unless the plants set enough seed before the roots were eaten, and the seeds germinate well, to establish a new generation of those species in the area. Also, a few side shoots and root fragments survived the digs and can regenerate full plants, but would this be enough to replace those eaten?

Another August hike took us—squelching all the way—to Cropley Lake in hopes of finding a blue gentian in flower and the yellow fireweed. Success! Also known as yellow willowherb, it usually grows along damp creek-sides and in montane meadows. It looks very different from the common pink-flowered fireweed, which is now classified in a different genus altogether. We also enjoyed some stands of the deep, rich purple monkshood flowers. There were hundreds of fringed grass of Parnassus flowers; in a previous essay, I related the history of how it may have got its name.

Yellow fireweed. Photo by Anne Sutton

At the very end of August, I went with a friend to the first meadow on the Spaulding trail. All across this meadow, we found many small diggings in the moss, leaving no evidence of who made them or what might have been taken. We found the seed heads of the strange little wetland plant called Scheuchzeria (sometimes called pod-grass). Widespread in the northern hemisphere, it has is currently classified in its own taxonomic family, and I have found very little information about its ecology and behavior.

A brief stop on a log for a snack provided a lucky sight of two chickadees: After conversing with each other in a nearby pine (no doubt about the odd lumps on the log), one by one they came down to a fruiting skunk cabbage. On each visit, the bird plucked one seed off the club-shaped infructescence, leaving a little empty pit, and flew off, but quickly returned. Jays and other critters sample these seeds too, sometimes leaving big bare patches, but it was good to see these little guys in action.

Transplants in Southeast Alaska

and the consequences of forced emigration

Since the 1920s, mammals of fourteen species have been transplanted from one location (mostly but not always in Alaska) to another location in Southeast. Many of the official transplants were done with the hope of establishing viable populations of game species in new places, with the goal of providing more prey for humans. The processes of capturing and transporting the unwilling immigrants commonly resulted in high mortality, even before the animals were deposited in their new sites.

Many of the transplantations failed. An attempt to establish a moose population near the Chickamin River in the 1960s failed altogether; all the transplanted young moose died. At that time, officials declared it was too expensive to do a preliminary habitat assessment and thought it more practical to just dump the moose there and see what happened. A number of other transplant attempts over several decades are said to have failed: deer to the Taiya Valley, goats to Chichagof, mink to Strait Island, muskrats and marmot to Prince of Wales, wolf to Coronation Island, snowshoe hare to Admiralty and other islands. Ill-advised attempts in the 40s and 50s to establish populations of non-native raccoons failed.

Some transplants were successful, apparently without any serious preliminary assessments: the mountain goats now living on Baranof are descendants of the transplants in the 1920s, and marten were moved to Prince of Wales, Baranof, and Chichagof in the 1940s and 1950s. After a habitat assessment in Berners Bay, a number of young moose were deposited there in 1958 and 1960; they established themselves successfully and that local population has grown. It may be emigrants from that area that we observe near Cowee Creek, Herbert River, and the Mendenhall Glacier. The possible effects of moose browsing on the structure of the vegetation in Berners Bay are apparently not known; given the notable cropping of willows and other shrubs in Gustavus, one might wonder about the effects on nesting habitats for birds—especially in the light of research elsewhere documenting that over-browsing can drastically reduce bird habitat.

Elk (a non-native species) were brought to four islands in Southeast in the mid to late 1900s. The elk, from Oregon and Washington, were exchanged for mountain goats from Alaska. Only the 1987 introduction of elk to Etolin Island was successful, and elk eventually dispersed from there to nearby Zarembo and other islands. Some preliminary habitat assessments were made, but post-facto concern about possible competition with existing deer populations arose, so continued monitoring and perhaps management are necessary.

After marten were transplanted to the three big islands, red squirrels were often introduced as prey for marten. It later became clear that marten really prefer voles and it is unlikely that the squirrel transplants had much effect on the introduced marten populations. However, it is very likely that the squirrels are having a negative impact on nesting birds on those islands, because they prey on eggs and nestlings.

Collectively, these attempts to establish new populations of mammals are a very mixed bag. There was a high cost in mortality of animals (not to mention dollar costs of capture and transport), many transplant efforts failed, and there was little attention paid to possible consequences. The impetus for game translocations in Southeast may have abated somewhat, and as our ecological understanding has grown over the years, it seems likely that any further transplants would be done with greater concern not only for the animals themselves but also for proper preliminary assessments and the ecological consequences.

Several additional transplants were done in attempts to augment existing populations or to re-establish a previously resident population. However, the effect of adding new animals to an existing population (deer to Kupreanof in 1979, for example) is usually not known. A transplant effort in 1989 attempted to restore a much-reduced population of mountain goats on Mt Juneau, with the stated intent of improved wildlife viewing (!). All the transported goats initially moved away, but by the early 2000s, goats were again seen on the ridge, although no one seems to know if these animals are related to the transplants or from a natural population on nearby ridges.

Sea otters have been re-introduced to many places in Southeast at various times, to restore the natural population that was extirpated by human activity. These transplants are apparently successful and the population of sea otters in Southeast is growing. The consequences of sea otter presence are currently being studied by faculty and students of UAF.

The historical information in this essay derived from Tom Paul’s 2009 ‘Game Transplants in Alaska”, ADFG Technical Bulletin #4. In addition to the official transplantations, there have been an unknown number of unofficial and mostly unrecorded ones, done by private citizens.

Aquatic plants

connecting aquatic and terrestrial worlds

Prompted by a discussion with another naturalist, I’ve been thinking about plants that grow in fresh or brackish waters and their unsung importance to animals. So this essay is about aquatic plants (collectively called macrophytes) such as pond lilies (Nuphar), milfoil (Myriophyllum), burreed (Sparganium) , buckbean (Menyanthes), pondweed (Potomogeton), water crowfoot (Ranunculus), ditch grass (Ruppia), arrowhead (Sagittaria), and some sedges (Carex) that play many ecological roles relative to animals. Therefore they also have numerous ramifying effects on many aspects of local ecosystems. Here are some examples.

Northern-Milfoil-underwater-by-Bob-Armstrong
Northern Milfoil. Photo by Bob Armstrong

These aquatic plants are eaten by animals. For example, Canada geese nibble the shoots of Lyngbye sedge out on the wetlands; later in the season they grub up the root, leaving characteristic divots. Sedge stands closer to the forest edge are grazed by bears, deer, and sometimes moose. Moose forage on buckbean and other aquatics (see this video by Bob Armstrong), which are reportedly very digestible forage plants and a good source of minerals. Geese, swans, and ducks graze on the leaves of milfoil, ditchgrass, burreed, ditch grass and other species too. Geese and ducks eat the seeds of sedge, milfoil, burreed, ditchgrass , and other species, in some cases passing undigested seeds through the digestive tract and thus dispersing the seeds. All of those animals are, at some point in their lives, potential prey for various predators.

Trumpeter-Swans-feeding-on-milfoil-in-Twin-Lakes-by-Bob-Armstrong
Swans feeding on milfoil. Photo by Bob Armstrong

Beavers (and humans and muskrats) dig up and eat the nutritious tubers of arrowhead; beavers also eat the yellow pond lilies, buckbean, and soft leaves of several species. Beavers are habitat engineers, creating pond habitat for nesting birds and juvenile salmon. They are prey for carnivores such as wolves; a recent report concludes that wolves are able to plan ahead to set up ambushes for beavers, as well as just running them down on land.

Some of these macrophytes (e.g., water crowfoot, buckbean, arrowhead, pond lilies) produce flowers that are pollinated by insects. The visiting insects may obtain nectar or pollen as food, and they are prey for several kinds of birds.

Damselflies have evolved an unusual use for these plants: female damselflies insert their eggs in the leaves and stems of various aquatic plants, sometimes submerging themselves for several minutes. The emerging larvae are predators on other insects and are themselves (as both larvae and adults) prey for other insects, fish, birds, and frogs.

Macrophytes provide protective cover for small fish, such as sticklebacks and salmon fry, which in turn are prey for larger fish, birds (such as kingfishers and mergansers), otter, and mink. Similarly, toad tadpoles and some aquatic insects hang out in the watery ‘forests’ of pondweed or milfoil, temporarily hiding from predatory insects, fish, or birds.

In addition to providing food, cover, and egg-laying sites, the standing ‘forests’ of aquatic plants provide a handy substrate for dense coatings of algae. Photosynthesis of the algae produces oxygen that improves the breathability of the water. The algae are eaten by toad tadpoles and by herbivorous invertebrates such as snails, which in turn are prey for fish and birds.

These ecological connections are relevant to local ponds (such as Twin Lakes) that are sometimes managed to reduce the density of milfoil and other macrophytes. The species of milfoil in those ponds has been identified as a native species (northern milfoil, Myriophyllum sibiricum). A study of this species (and the invasive Eurasian milfoil, M. spicatum) in eastern North America showed that the native species generally supported more snails and other invertebrates than the invasive species. Those rich communities of invertebrates provide food for fish and waterfowl. Some of the waterfowl also graze directly on milfoil. Thus it becomes important to understand the ecological effects of reducing milfoil density in the lakes. How is the foraging of fish and birds changed? Also, perhaps reducing the density of the native milfoil facilitates invasion by the Eurasian species (widespread in North America and it might be in our area too), which supports poorer invertebrate communities. Furthermore, the invader can hybridize with the native species, changing its palatability or digestibility along with the associated composition of the algal community, with resultant effects on the animals that use milfoil. Hmmm, a potential research project awaiting attention…

Pines

some tidbits about a lesser-known local tree

On a nice winter day, a cluster of Parks and Rec hikers perched for lunch at the edge of a beautiful muskeg. Someone observed that many of the shore pines were rather stunted and often crooked, while others grew straight and tall. Our local shore pines are a distinct subspecies of lodgepole pine, which grows mainly in the Interior; its straight, tall growth form gave the species its common name. Some of these Interior-type lodgepoles are reported from the north end of Lynn Canal.

The question, that day, was whether or not the tall specimens in our muskeg might be strays from up north. Someone remembered that there are subtle differences between the subspecies in the orientation of the cones on the branches. But without a detailed genetic analysis, this notion probably cannot be ruled out—after all, these pines use the wind to disperse both pollen and seeds, and who’s to say that no genes from the upper Lynn Canal population have ever come to Juneau.

On the other hand, we observed that the tall, straight pines in our muskeg grew chiefly along the edges, near the surrounding spruce and hemlock forest. This distribution suggested to us that maybe the growth form is determined by habitat; for instance, muskeg edges tend to be dryer than the main part, and perhaps the acidity is somewhat less, too. A little research, back at home, revealed that expert plant ecologists have come to the same conclusion.

shore-pine
The “contorta” subspecies. Photo by Kathy Hocker

That little discussion reminded me that pines are interesting in several ways. I have room to deal with one of them here.

About forty species of pine occur in North America (out of over 100, worldwide). Most of these produce seeds with well-developed, flat wings; they are adapted for wind-dispersal when the cones open and shed the seeds. Just a few kinds lack wings altogether or have extremely small wings.

The best-known North American species with wingless seeds are the several closely-related species of pinyon pine. They grow on poor soils in dry areas of southwestern U.S. and Mexico. The seeds are large, over a centimeter long, and well-endowed with highly nutritious endosperm (about 60% fat) to fuel the growth of seedlings. When the seeds are mature, the cones open but hold the seeds on the cone scales, not releasing them to just fall to the ground. This is considered to be an adaptation for seed dispersal by birds, principally pinyon jays and Clark’s nutcracker, although scrub jays and others also participate. The birds harvest ripe seeds from the handily open cones and commonly cache them all over the landscape, sometimes may kilometers away from the parent tree. Many of the cached seeds are retrieved and eaten by these birds with excellent memories, but some are lost—and these can produce new trees for another generation. Squirrels don’t miss these tasty bites, of course, but they are mainly seed predators. Any fallen seeds—and some cached ones—are scarfed up by rodents, quail, and other ground foragers, including humans.

Pinyon jays and Clark’s nutcrackers both have very strong bills, for hacking open closed, green cones early in the season, before the cones open. Both species have special anatomical adaptations for carrying loads of seeds to caches. The upper esophagus of the jays expands when it is packed with seeds; as many as forty pine seeds can be carried at one time. Clark’s nutcracker has a pouch under the tongue where dozens of seeds can be carried. Both of these birds eat other kinds of seeds too, as well as insects and other foods, but the relationship between the birds and the pinyons is considered to mutualistic—with benefits to both sides. Less specialized birds, such as scrub jays, participate in the mutualism, but the relationship is less specialized.

Two additional pine species (limber pine, southwestern white pine) in western North America make seeds with vanishingly small wings; their seeds also dispersed by caching birds. Seeds are released from the cones when mature and are available then to ground foragers. The seeds of the southwestern white pine are eagerly harvested and cached by Mexican jays, which cannot open green cones well and apparently eat more acorns than pine seeds.

One more North American species (whitebark pine) makes wingless seeds. But in this species the cones do not open readily. This species grows in montane forests of the western U. S. and British Columbia, where seed-harvesting birds and squirrels generally have to open the cones to extract the seeds. The caches of these harvesters are regularly raided by black and grizzly bears. At least in some areas and some years, this food source contributes significantly to the survival and reproductive success of the bears.

Wingless pine seeds also occur in Eurasia, where winglessness seems to have evolved independently several times. The spotted nutcracker there participates in a mutualism similar to that in North America., but the Eurasian jay seems to be more closely associated with acorns and beechnuts (as is the blue jay of eastern North America). Who else might participate in a mutualism with wingless-seeded pines in Eurasia?

Another question: What are the historical and ecological factors that determined the lack of wingless pine seeds in Southeast, where the seeds of all conifers are basically dispersed by wind?

Spring medley

progress of a favorite season

Spring is officially here: the vernal equinox has gone by and the days are rapidly lengthening. There are much livelier signs of spring as well. Sapsuckers have arrived in force, rat-atat-tating on rain gutters and stove pipes (and trees). Juncos trill at the forest edge and song sparrows are tuning up in the brush above the beaches. Pacific wrens sound off from invisible lookouts in the understory. Best of all, ruby-crowned kinglets can be heard, high in the conifers, calling ‘peter-peter-peter’ or singing their full, cheerful song. That’s when spring is really here, for me.

A walk on a favorite beach on Douglas Island was focused on finding mermaids’ purses—the egg cases of long-nosed skates. Every year, about this time, we find them washed up in the wrack at the high tide line—there must be a nursery just offshore. On this day, we found sixteen eggs cases, mostly black, dry, and in various stages of decrepitude. Just a few were still mostly whole and khaki-colored, and two had natural openings at one end, where perhaps the young skate had exited. All the egg cases had sizable holes punched into them. I would love to know if marine predators had nabbed the developing embryos or if the holes were made by a tardy, would-be predator just hoping that an embryo was still inside.

A good find in the rolled mats of rockweed at the high tide line was the body of a sea star, entirely eviscerated. All the gonads and digestive parts had been cleanly removed, neatly exposing the calcareous skeleton of the water-vascular system that runs from the center of the star out into each arm. In a living sea star, the canals of this hydraulic system are filled with fluid, mostly sea water. Numerous branches of the main canal lead to the tube feet (often visible in a live star, in rows under each arm) that function in locomotion and in opening clams. When the tube feet are extended, their ends stick to the rocks or the clam shell, and muscles in the feet contract, pulling the animal forward or pulling the clam shell open. We sometimes see a sea star humped up over a partly open clam while the star is having dinner.

A stroll on the Boy Scout/Crow Point trail led to the goose-flat covered with hundreds of crows fossicking in the dead, brown vegetation. Lots of searching and probing. Sometimes half a dozen crows would suddenly converge on another one, everybody poking at something. Apparently, successful hunts were not very common and the gang thought that sharing was appropriate.

Lots of Canada geese were scattered in small groups on the flats, in the river, and in the vegetation by the river. There were mostly head-down, intent on foraging—grubbing for roots and such, and of course talking to each other. Occasionally, two of them would take off and wing around in a wide circle before landing back where they started. One of these duos took off upstream—perhaps a mated pair about to look for a nest site in the forest.

As we often do, out there, we encountered a fellow we call the Raven Man, who carried a big bag of dog biscuits to feed the ravens. He does this from time to time, and the local ravens recognize him. As he passes through each raven territory, the residents come to greet him and cadge some biscuits. We watched some of these ravens carry five biscuits at a time, first stacking them up in a neat pile so they could be held in the bill. A dog, with some hikers, came along later and sniffed out places where ravens had cached their loot, covering it with grass or moss—surprising the hikers who were not expecting to see dog biscuits in the moss.

Most folks in Juneau are glad to see the snow disappear, at least at the lower elevations. But I loved the good snows we had in February, and here are a few flash-back memories.

–Weasels had been very active in the Peterson Creek meadows and Amalga meadows. They bounded over the clean snow, ranging widely. Every so often, the trail dove straight down under the snow and re-appeared a few feet beyond or disappeared under the overhanging edge of a frozen slough. I think they were hunting voles, whose tunnels run under the snow; did they dive down in response to the sound or fresh smell of vole or were the dives just exploratory? Another treat in one meadow were well-defined trails of mice, showing a good tail-drag.

–On the west side of Mendenhall Lake, one day I found a set of tracks running way out onto the snowy ice and right back again. It was clearly a member of the weasel family, probably a mink. What was it doing??

–A snowshoe trek up a creek out the road was a bonanza of tracks (and no recent human tracks). In the woods on the way up the hill, there were tracks of deer, mouse, weasel, squirrel, and maybe a marten. Big excitement of some large tracks that were surely those of a wolverine—the toes and the gait gave it away. The most fun was seeing a set of wolf tracks coursing over a frozen pond that sparkled with sun-struck hoarfrost.

Now the fun in the snow is finished for the year, and the fun of spring begins. Juneau folks typically love to note the progress of spring, as the season unfolds. Skunk cabbage emerging, pussy willows appearing, blueberry buds expanding, the gradual arrival of more kinds of birds, ravens carrying sticks for a nest—they all mark the progress of a favorite season.

Fungi and Wildlife

animal harvesters of fungal delights

Fungi are made up of vegetative parts, which are filamentous structures that typically lie underground, and reproductive parts, which take various forms, sometimes finger-like or shelves, or commonly as mushrooms with a stalk and a cap. But some fungi never produce above-ground parts; the small, round or lumpy reproductive structures are underground—these are known as truffles.

Fungi reproduce by means of spores—each tiny spore containing the makings of a new individual. Most fungi, such as ordinary mushrooms, disperse their spores aerially—releasing the mature spores from the mushroom cap to vagrant breezes in the forest understory. Truffles do it differently: they rely on small mammals to dig them up and eat them, passing the spores through the digestive tract and depositing them in feces.

Here in Southeast, there are two major harvesters of truffles: the red squirrel and the flying squirrel. The red-backed vole also does this and other small mammals may do so occasionally. These rodents also harvest typical mushrooms, sometimes caching them, to be eaten later, after they dry. Red squirrels do this very regularly; flying squirrels in other regions cache many kinds of food but apparently they have not been recorded to do so in Alaska.

squirrel-with-mushroom-by-bob-armstrong
Photo by Bob Armstrong

The caloric content of fresh mushrooms is low, far lower than that of nuts and seeds. However, dried mushrooms compare more favorably, although they still average only about two-thirds of the caloric content of conifer seeds. Mushrooms are very low in fat, compared to spruce and hemlock seeds, but they can be a pretty good source of carbohydrates and protein, especially when dried. They may also provide an assortment of micronutrients such as vitamins and minerals. Fresh mushrooms can be a source of water during season dry periods.

However, the actual food value of fungi to rodent consumers depends in part on the intake rate. Taking a bite of mushroom or truffle is quick and easy. But when eating conifer seeds, squirrels have to peel back the cone scale and trim the membranous ‘wing’ from each seed before eating it. Although squirrels are remarkably fast at extracting conifer seeds from a cone, it still seems that the food intake rate would be slower than when eating fungi. The actual food value also depends on how efficiently a squirrel’s digestive process extracts energy and nutrients from the material that is ingested. Some studies of squirrel diets suggest that the digestibility of fungal tissue is considerably less than that of conifer seeds. Nevertheless, squirrels regularly eat fungi, so there must be sufficient reward to make it worthwhile.

The relationship between truffles and squirrels (and voles) is mutualistic—the mammals get dinner and the truffles disperse their spores. For truffles, the relationship is obligatory; they are dependent on small mammals for spore dispersal. For the rodents, the relationship is more variable, depending in part on the availability other food sources (for example, squirrels might eat more truffles in years when the cone crop is poor). Mushroom-producing fungi sometimes get spores dispersed by rodents that harvest mushrooms; the spores ingested are viable after passing through the rodent’s guts, so in addition to the normal, aerial means, the fungi benefit from rodent assistance. This amounts to a casual sort of mutualism in which both parties benefit but the relationship is not obligatory for either one (in contrast to that for truffles).

Now the plot thickens! Many fungi, both truffles and mushrooms, are mycorrhizal—forming mutualistic relationships with the roots of various plants. The plants provide carbohydrates to the growing fungi and the fungi supply various nutrients to the plants. In most cases, both participants in the relationship grow better with the partner than they do alone; in some cases the relationship is obligatory to at least one of the partners.

Thus, in this network of interactions, one well-developed mutualism (the fungus-plant relationship) intersects with another one (the rodent-fungus relationship). Something for everybody! A nicely tangled web!

Rambles in Gustavus

blossoms and birds, tadpoles and otters and a leguminous puzzle

I recently spent a couple of days roaming the trails in Gustavus, along with three other curious naturalists. Gustavus lies on the outwash plain created when the melting glacier of Glacier Bay poured its silty, gravelly meltwaters through Cooper’s Notch. Post-glacial rising of the land made the sandy plain more expansive. Now Gustavus offers a different array of habitats than are found in the nearby spruce-hemlock forest at Bartlett Cove or in Juneau. I love to visit Gustavus to visit friends but also because I enjoy the variety that’s just a nice ferry ride away.

One of our excursions took us on the Nagoonberry Trail, which passes through meadows, shrublands, and young spruce groves. Just for fun, we counted the number of wildflowers that we found in bloom. There were at least forty-seven species, exclusive of grasses and sedges. For comparison, a similar recent count in the lower subalpine zone on Gold Ridge turned up over fifty species—and there would have been more if we’d gone to the top of the ridge. A few years ago, we found over seventy flowering wildflowers in Cowee Meadows. I think that’s quite impressive. We don’t have to go to the tropics to find good diversity.

For some reason, lady-slipper orchids of several species are found in Gustavus, although I’ve never seen one in Juneau. A favorite one is the sparrow’s-egg orchid, with its very small ‘slipper’; it is also reported to be common in the Yukon. This species self-pollinates, and we found a robust specimen in which every flower had produced a fat seed pod. Nearby, there were three other kinds of orchids in bloom. I don’t recall any place in Juneau where I’ve seen four kinds of orchids growing within a few feet of each other.

We were entertained by bird families wherever we went. Lots of little ‘chip’ notes or thin ‘seet’ notes drew our attention to fluttering wings in the vegetation, which turned out to be little groups of juveniles with their parents—ruby-crowned kinglets, juncos, savanna sparrows, and chickadees. Young barn swallows were on the wing too. Lincoln’s sparrows were singing frequently, perhaps thinking about second broods. Sadly, we found two dead, well-grown juvenile hermit thrushes, in two different locations and so presumably not of the same family. They were very thin, and we wondered if the recent dry conditions had made it hard for them to find their own food.

We made a now-traditional visit to the gravel pits to look for toad tadpoles (aka pollywogs). Thousands of them were tightly clustered in the shallows at the bottom of a pool. At this time, only a few had started to grow hind legs; most of them were still just tadpoles. Presumably most of the remainder (if they survive lurking predators) will metamorphose and disperse as tiny toadlets later in the summer. I was curious about the derivation of their names. An internet source claims that both names come from Middle English: the first means ‘toad-head’ and the second one means ‘head-wiggle’.

One morning we were gifted with a boat exploration of the lower part of Glacier Bay. Around the long, low moraine at Point Carolus there were humpbacks breaching and kittiwakes foraging. Little flocks of red-necked phalaropes flitted about. Phalaropes are unusual because in these species it is the males who do the parental care and the females who are more colorful and aggressive; sometimes a female has two males on her territory, rearing their chicks. On the way back into Bartlett Cove we paralleled a roving pod of transient killer whales. Even the tourists ashore in the cove could watch these whales, but they probably could not observe that a sea otter speedily departed in the opposite direction from that of the killer whales.

Everywhere we looked in the lower bay there were sea otters, foraging and loafing. Our boat captain reported that on trips up-Bay, sea otters were observed hauled out on icebergs and reefs, a behavior seldom reported (in my hearing or reading, at least). This observation reminded me of the historical accounts of the emergency camp of the St Peter’s crew on Bering Island during the winter of 1741-1742, when Captain Bering died and Georg Steller discovered the now-extinct sea cow. The stranded, sickly crew unwittingly wiped out an entire species of flightless cormorant, as well as uncounted numbers of foxes, ptarmigan, and other animals. They slaughtered many hundreds of sea otters, partly for the furs (to gamble with, while passing the time!) and partly to eat. Great numbers of sea otters were hauled out on beaches, where they had never experienced any predators, and were (at first) ignorant of predatory humans, making them easy to slaughter. It seems that sea otters are more inclined to use terrestrial (or icy) haulouts in times and places where they are not harassed or persecuted.

We interrupted the boat ride with a short beach walk on the west side of Glacier Bay. Here we found that others had walked the beach before us, leaving evidence of their passing. Big moose tracks, indistinct prints of canids (wolf or coyote), and very impressive tracks of a big brown bear (at least eight inches wide), along with some prints of a quite small bear. That made us extra-alert.

On many of our Gustavian rambles we saw the purple and pink flowers of beach pea. Or so I thought. A more knowledgeable naturalist said No, not all of those are beach pea. Some have smaller, paler flowers and tend to be less sprawling than ordinary beach pea. So then we began to look more closely and, indeed, there were two different kinds of pea (closely related, in the same genus). The vibrantly colored beach pea has angular stems with no flanges (or ‘wings’), while the paler, smaller-flowered one has stems with wings. That one is called ‘wild pea’ in one field guide but is not even mentioned in another. So now I must revisit some of the Juneau beaches to see if wild pea grows here too.

Altogether, a highly satisfactory Gustavian visit in the company of fine companions.