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Learning to See

Willingness, mindfulness, focus, and detective work

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the question is not what you look at–but how you look and whether you see. (Thoreau 1851)

In my weekly essays I commonly report small natural history observations noted during a walk in the forest or meadows. Readers of these essays sometimes ask me how I manage to notice the little things I frequently write about—a trail of a small beast in the mud, an odd excrescence on a twig, hairs caught on tree bark, a bee sleeping among goldenrod flowers. Well, that is easily answered: I am interested! And that is the starting point.

So if you think you might be interested in learning How to see, or How to see better, or How to see more, while taking a walk on or off trail, keep reading. And, although I am putting this in terms of seeing, the same principles apply to our other senses.

I think the process of really seeing things can be broken into four stages:

Stage 1. Being willing to become engaged in the process of observation of natural history. It is not necessary to be a naturalist at the beginning; as experience grows and observations accumulate, you have more background to build on, and a beginning naturalist is hatched. But it is entirely necessary to be willing.

Stage 2. This could be called mindfulness or ‘being there’. Although we often think about many things while taking a walk—maybe health problems, or what to make for dinner, or books you’ve been reading—take some time to be aware of where you are and what is around you. Even while talking with a friend, use your peripheral vision and let one part of your mind catch something that’s unusual or different. Maybe it is a change in pattern—an unexpected flower color, a dark spot in a field of yellow, a lump on a pine branch. Let it spark your curiosity.

Stage 3. Focus. Look more closely at what caught your peripheral vision and ask questions. Is it a flower that you don’t recognize? What are all those flies or bees doing? Why did those gulls suddenly fly up in a big swirl and move down the beach? What made those leaves roll up into cylinders? What could have made that narrow, wiggly trail in the mud?

Stage 4. Detective work. Try to answer at least some of your questions. This may involve more observations, or looking things up in a book or on-line, or consulting a local expert. Or you can be satisfied just by noticing things and looking more closely.

cow-parsnip-by-bob-armstrong
Photo by Bob Armstrong

Here is an example. You are walking on Perseverance Trail in summer. You are vaguely aware of a lot of white, flat-topped inflorescences on tall stems near the trail. You may or may not know the plant is called cow parsnip or Indian rhubarb. Most of the inflorescences might have a small fly or two crawling around—barely worth noticing, maybe—but one of them looks darker and has a dozen or so flies of various sizes, making it look different from the others. As you watch, you notice that the flies are probing into the tiny flowers that comprise the inflorescence, possibly eating nectar and pollinating the flowers as they move around. But one of the ‘flies’ looks a little different from the others; it has longer legs, a thinner abdomen. And as you watch, you see it probing flowers like the other insects but gradually sidling up to a feeding fly and pouncing on it! Wolf in sheep’s clothing! Not a real fly, but a predatory wasp.

That simple observation could lead on—to finding out the identification of the wasp and more of its life history, to reading about other sneaky predators, to figuring out the effect of the wasp on pollination, to looking for similar behavior on other types of flowers, and so on—depending on how much detective work you want to do. In short, you have discovered a STORY, one that could be expanded in several directions.

These activities are not the choice of everyone. But if you are willing, and have a little bump of curiosity, and take the time to pay attention, you will find many small stories—connections among things, contrasts or parallels among other things—and all of this enriches a walk.

It’s fun to do these story-searches by yourself. But it’s even more fun to do them with a friend. I have two dear friends that share this fun with me rather regularly (and whose thoughts contributed substantially to this essay).We complement each other, noticing different things, asking different questions, contemplating different answers. Try it!

The rare moment is not the moment when there is something worth looking at but the moment when we are capable of seeing. Joseph Wood Krutch 1951

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.

Excursion to Kluane Park

observations on the dry side of the Coast Range

Past an intensive construction zone, where the Chilkat River had begun to threaten the highway, up over the Three Guardsmen pass, and there it begins—those splendid, wide, sweeping vistas of broad valleys, flanked by sharp-peaked mountains to the west. Trumpeter swans raise their cygnets in the ponds and marshes alongside the road. Long stretches of the highway are lined with bright purple flowers; without a specimen in my hand now, I cannot say which of two species it might be (Confusingly, both are sometimes called sweet-vetch, but only the one that is also called bear root or Indian potato is nonpoisonous and edible).

It’s late June and, with a few friends, I’m bound for a few days of exploring some of the trails in the southern part of Kluane Park. This trip also requires important visits to the bakery in Haines and especially the one in Haines Junction (offering first-class nanaimo bars!). A new and elegant visitor center in Haines Junction houses many fine exhibits of First-Nation crafts and natural history.

As we came down the north side of the pass, we saw a number of Arctic ground squirrels beside the road. They are familiarly–but inaccurately–often called ‘gophers’, but they are quite different from true gophers. Arctic ground squirrels here are near the southernmost part of their broad geographic range (all across Canada and eastern Siberia). They have a very long hibernation period, going to bed in late summer and early fall, not coming out again until spring. Females survive this time on stored body fat, but males make a cache of seeds in their winter burrows. They feed on this cache for a couple of weeks before they emerge in the spring, regaining the weight lost during the long winter fast. The food stash allows them to be ready and waiting for the females, which emerge from their winter burrows somewhat later than the males. Each male has a territory, defended vigorously against other males; a territory encompasses the burrows of several females, but a female is only receptive to mating for about four hours, so the males have to be ready. A territorial male usually sires about ninety percent of the ensuing pups born to the females on his territory, but a few are sired by extracurricular activity.

Descending farther, we entered the forested zone, where some of the conifer stands show signs of the spruce bark beetle infestation that has been in the news. Huge areas are covered with quaking aspen trees, famed (and named) for their trembling leaves that catch the sunlight. (Unlike the leaves of most trees, these have flat, not round, petioles, which let them flutter more). Many of these aspen stands had an understory of blue lupines and bluebells that contrasted beautifully with the pale tree trunks, emphasized by the sunlight that filtered through the canopy of dancing leaves.

As we walked through some of these aspen stands, we noted that some of the leaves looked, not green, but silvery. Looking more closely, we saw that leaf miners had been at work, leaving closely packed, sinuous trails where the tiny larval insect had eaten away the epidermis, leaving a swath of white on either side of its path and a black line of frass (excrement) down the middle. The aspen leaf miner is a moth; an adult female lays an egg in a rolled-up leaf edge and the larva chews its way around the surface of the leaf before pupating in its mine. An emerging adult moth overwinters under bark and other such crevices.

Sometimes huge populations of this leaf miner build up, turning whole aspen stands to silver. The middle layers of leaf cells, where photosynthesis (forming carbohydrates from carbon dioxide and water) takes place, is undisturbed, because the moth larvae eat only the epidermis of the leaves. A study in Alaska found that mines on the upper surface of the leaf do not greatly interfere with photosynthesis and so do little harm to the tree, but mines on the undersurface prevent the stomates (small openings) from regulating the passage of water vapor, and that in turn interferes with photosynthesis and so can affect the health of the tree. Trees with lots of mines, especially on the leaf undersurfaces, do not grow as well as others.

A little plant often known as bastard toadflax was extremely common in the forest understory. This is a hemiparasite: it has green leaves and can photosynthesize carbohydrates but it also gets some of its nutrition from other plants of many species, including spruce, aspen, rose, aster, and so on. It occurs in Juneau too, but here it is far less common. I wonder why!

In the sandy soils along several trails, we saw a number of fairly large ant hills, two or three feet across, with several entrances—something we don’t see in Juneau. In some other North American forests, certain ants are important seed dispersers for particular species; these seeds typically have attractive attachments that draw in the ants, which collect the seeds and eat the attractive bit, dropping the seed somewhere away from the seed’s parent. Seeing those anthills made me wonder if this ecological interaction might occur here too.

We came upon a ruffed grouse on the trail in one of the aspen stands. She had a brood of chicks in the nearby shrubbery, and I suspect she was thinking about crossing the trail with her family. However, our coming disturbed her and she put on a wonderful display of ruffled ruff and fanned tail feathers, accompanied by annoyed clucking. The chicks scuttled farther back into the brush, and she settled down after we slunk past.

Ruffed-grouse-female-display-Kerry
Photo by Kerry Howard

This being June, we saw a riot of flowers almost everywhere we went: pink flowers of prickly rose and twinflower, bright yellows of stonecrop and buttercups, pale yellow of oxytropes, white of mountain avens, dwarf dogwood, and Labrador tea, purples and blues of louseworts, wild flax, columbines, and penstemon (aka beardtongue)—a visual treat on every side. We found a showy sparrows-egg orchid and a yellow, parasitic orchid; something new for us was the white-flowered death camas (deadly poison, so it must be distinguished from the edible species of camas!).

This being June in the Interior, it was also mosquito season. On most of the trails, a cool breeze cut down their depredations, but in our cabin it was another story. We called our temporary home “Mosquito Ranch” for the number of mozzies that gathered there (no blame to the very genial owners of the place!). We made a game of demolishing them and slept under mosquito nets. And I bet that the barn swallows were very happy indeed.

Potluck

a selection of summer delicacies

You never know what might be offered at a potluck supper, where you browse over a miscellaneous collection of dishes. This essay is a bit like that—an assortment of unrelated but potentially interesting observations and information.

Last week I mentioned the great abundance of mosquitoes in June in the Interior. Mosquitoes can surely be a major nuisance and in some regions of the world they carry diseases and parasites. But is there another side to this coin?? What good are mosquitoes?

Mosquitos are good bird food. Swallows and swifts catch them on the wing. Certain warblers and flycatchers dart out from a perch to catch them as they fly by. I’d bet that the female hummingbird swooping back and forth in my front yard catches some, too. Mosquito larvae are aquatic and provide good prey for small fish and for larger invertebrates that are also prey for fish. Dragonflies and damselflies feast on them.

Mosquitoes are more than unwilling prey, however; they are the principal pollinators of a diminutive-flowered plant called the small bog orchid. In Alaska, males and females of several species of mosquito are known to visit these orchid flowers and carry pollen from on flower to another (other insect visitors include small moths and flies, but their role in pollination is undocumented). As the mosquitoes poke into a flower, globs of pollen are slapped onto their eyes, where they stick until the mosquito goes to another flower, which is arranged in a way to pull off the pollen, leading to seed development. There may well be other kinds of small flowers that are pollinated by mosquitoes: male mosquitoes commonly live on nectar from flowers and even the blood-sucking females do to in some cases. Some of these visitations might achieve pollen transfer, but sometimes the mosquito might be just a nectar thief.

Flower color is one of the cues used by flower-visiting animals. Color helps identify the species, sometimes the age of the flower, and in some cases, whether or not it has already been visited by a pollinator. Usually, all the flowers of a particular species are the same color, or nearly so. But we see exceptions. For example, almost all of the chocolate lilies we see have brownish flowers, but very rarely we see one with yellowish flowers. Wild lupines normally have blue to purple flowers, but in rare cases we find one with pink flowers. Occasionally, we’ve found white-flowered individuals of fireweed, northern geranium, shooting star, and bluebells (whose flowers are normally pink or blue). These very unusual flower colors are presumably the result of genetic mutations.

yellow-chocolate-lilies-Denise.jpg
Photo by Denise Carroll

These mutants don’t seem to spread and become more common in their respective populations. But why? Do pollinators discriminate against those oddballs, leaving them unvisited, unpollinated, and without offspring? Or, maybe the (presumed) gene that controls flower color also controls something else in the plant’s life, something that interferes with some aspect of normal function. Multiple effects of single genes are common. As usual, a simple observation leads to more questions.

Bumble bees are very important pollinators of many kinds of flowers. They are the principal pollinators of monkshood, lupine, blueberries, iris, louseworts, and beach pea, which have flowers that must be manipulated in a certain way in order to achieve pollination. But the bees also join with a variety of other critters to pollinate roses, salmonberry, thimbleberry, goldenrod, and columbine (to mention just a few).

However, all across North America, from California to the east coast, populations of some bumblebee species have become very rare or even disappeared entirely. Because I have a very unscientific impression that I see fewer bumblebees on our wildflowers in the last two years than previously, I wondered if our bees may also have crashed. I asked the UAF expert, who said that a study currently underway in Denali is designed to detect major changes in bumblebee populations there, but as so often happens, these seem to be no scientific data for Southeast. We can hope that our bumblebees are in good shape, because so many of our wildflowers depend on them.

Finally, and just for fun (?dessert at a potluck?): One day I walked through the Eagle Beach day-use area after a stroll on the beach. I spotted a big black bird sitting on a rock and holding a chunk of something red and drippy in its bill. Through binoculars, I saw that the raven held a succulent piece of watermelon. Just beyond the rock was a picnic table with several plastic containers, temporarily abandoned by a human family that was playing out on the intertidal sand flats. At least two of those containers had the lids removed (?by the raven?) and one of them still held a chunk of melon. That family was in for a surprise when they came back to their table!

Low tide explorations

a plethora of crabs, siphoning sponges, and other intertidal delights

June brought some good low tides, lower than minus four feet, so out we went to look at the rocky intertidal zone. This is always a little voyage of discovery, seeing some old ‘friends’ and finding some new ones. But I sure wish that some nice intertidal biologist would come with us, to answer our many questions!

We went out on two consecutive days, to two different sites. These two places differed greatly in the composition of the invertebrate community. For instance, at one site, the false white sea cucumber was overwhelmingly abundant, but at the other site, it was very rare…although the big orange sea cucumber was common there. The little black ‘tar-spot’ cucumbers were extremely plentiful at the first site, but they were not common at the second one. Crabs were hard to find at the first site but common, and of several different species, at the other. Such differences might be due, in part, to the difference in the amount of exposed bedrock habitat vs cobbles, but a real intertidal biologist could probably suggest some other possible explanations for the differences.

I picked up a big whelk shell and had a brief look at a bright red hermit crab rapidly retreating into the top of the shell’s spiral. This Pacific red hermit had found a shell so big that it could disappear entirely from view. Nice for protection, but the shell was so big compared to the crab that there was no way the crab could move its big house from one place to another.

Carefully turning over rocks, we often exposed small fish called pricklebacks. People erroneously or confusedly call them all sorts of names: blennies, eels, snakes, worms, wigglers, flippers, and whatnot. Pricklebacks, and the much less common crescent gunnels, can survive a low tide in damp, protected spots (such as under rocks, where ravens and gulls can’t grab them), because they can breathe through their skin.

Among the several kinds of crab were some brown ones totally covered with short bristles (helmet crabs, I think). We picked up one, only to find that it was an empty shell—the crab was gone. The shell was undamaged, but it was easy to lift open the back of the shell and view the interior. This crab had molted its old shell (along with the barnacles clinging to the legs), pulled its legs and eye and other parts free, and backed out. Now it had to produce a new hard shell, which must take some time, leaving the soft-bodied crab very vulnerable to predators. And the cost of making a new hard shell must be considerable. But a critter with a hard external skeleton can only grow by shedding the old one and making a new one.

Perched among the stubby fronds of an alga were several hairy snails—not very big, with very bristly shells. Something new for us! The usual kind of hairy snail appears to have a short life. After a larval stage, a young snail is male for the first year of its adult life. In its second year, it becomes female (while retaining the penis, just behind one eye), mates with a young male, lays eggs, and dies. An interesting way to go about things—I have to wonder what factors favored the evolution of this life history.

At one site, we found several crumb-of-bread sponges, yellowish in color, encrusting the rock. They break apart easily, hence their common name. I’ve read that a good diagnostic feature is their odor, said to smell like exploded gunpowder. Sponges are multicellular animals that have a very long fossil record, back to the earliest evolution of animals. They feed by pumping in water through small pores and passing water currents though the body, filtering out microorganisms. Several volcano-like structures are scattered over the body of this sponge; water currents and undigested food exit the sponge via these openings. The body is laced with glassy spicules made of silica but, nevertheless, it is eaten by various molluscs and other things. It simply can spread over the rock, but it can also reproduce sexually. However, unlike most sponges, this one has separate sexes.

Under a few flat rocks, there were several small, grub-like animals with no visible appendages that we’d not seen before. With long-distance help from an expert, these were identified as sandpeanuts, a kind of polychaete worm. It usually lives in the sediment below the mid-tide level and feeds on small bits of debris caught by its little tentacles. Without a hand-lens, we could not see the numerous tiny bumps and hairs that are distributed all over the body, nor did we discern the many ill-defined body segments. The feeding apparatus and gills at the front end can be retracted, so they are not visible when the animal is exposed by a low tide. No wonder we had a hard time figuring out what it might be!

I came upon a charming scene—a father with two small children (and a friendly dog) had found a small rock crab. The father carefully picked it up, showing the kids how to avoid the big pincers at the front end. After they all looked at the crab, it was gently placed back where they found it, and it wedged itself tightly between two rocks. What a good example of how to teach exploring kids.

Sheep Creek Valley

nest-building, a song chorus, and a wildflower show

In early June, Parks & Rec hikers went up the Sheep Creek trail on a day of fitful rain showers and intermittent sunshine. This is a favorite trail, but it was clear that the trail could use some work! The uphill portion of the trail is seriously eroded by water coursing down the trail. The long traverse below the road is cut by deep erosional gullies and the edge of the trail is collapsing in spots. Along this stretch, cow parsnip overhangs and obscures the trail. Once in the valley proper, the going is easier, although several wind-shattered cottonwoods and sagging willows lie across the trail and there are more erosion cuts. Some of these things are easily fixed, while others are significantly more challenging.

This was a good time to go up into the valley, because it is rich in nesting, singing songbirds. Even though the P&R summer hikes begin well after the early-morning chorus of bird song (and my hearing is not as good as it once was), I identified the songs of twelve songbird species, plus hooters on the hillsides. One species, in particular, was a treat: Swainson’s thrushes commonly nest up there but they arrive later than the others; I don’t usually hear them until June. By that time, robins and fox sparrows are feeding chicks and juncos have fledglings.

swainson's-thrush-by-bob-armstrong
Swainson’s thrush with nest material. Photo by Bob Armstrong

Swainson’s thrushes nest all across northern North America and down along the Rockies. They spend the winter mostly in southern Central America and northern South America, although some go as far as northern Argentina. When they at last arrive here in spring, the female builds a nest, usually in the understory, lays her eggs and incubates them, while the male sings. But both parents tend the chicks. Hearing the song of that species is certainly a treat for me, but my favorite remains the ruby-crowned kinglet’s cheering carols from the canopy.

Right next to the trail we found a very large scat of a carnivore, full of fur and bones, artistically arranged. A wolf (or possibly a bear) had dined well, probably on marmot.

On this hike, some of the wild flowers were appearing—lots of buttercups, some chocolate lilies and miner’s lettuce, three kinds of violets, a few enchanter’s nightshade. Occasional salmonberry canes bore flowers, but there were wide stands of dead canes, some of which showed no evidence (?yet) of new canes coming up at the bases of the old ones. Does that bode ill for salmonberry production up here this year?

A special floral sighting was a clump of some kind of saxifrage, growing on boulder. We’d seen this on previous hikes too and noted the leaves with three sharp terminal teeth. That made identification simple—the three-toothed saxifrage. The leaf margins have scattered hairs, a feature that led us astray for a while, but consultation with real botanists eliminated the confusion and confirmed the name. This species is not common in our area, but it seems to be the only saxifrage here with three-toothed leaves. The white petals have reddish spots on them (so does another species, but that one has different leaves). It’s fun to try to figure out such things and learn new species; now if I can just remember all the distinguishing features…

Of course, having the right name is just a small part of any story! Many questions lie in wait for curious naturalists. What insects pollinate this plant? What is the function of the spots on the petals? Do the marginal hairs on the leaf deter some herbivores? Does this plant typically grow on rocks? And so on. That’s where the real interest and fun lie!

Just for fun of a different sort, on a completely different topic: I put up a peanut butter feeder on my deck this spring. A simple thing, it consists of a small block of wood with pits (for peanut butter) drilled into both sides of it. This dangles on a hook where I can see it easily, while lazing in my big comfortable chair. The chickadees found it almost immediately and visit it regularly. Did they know that this funny-looking thing might have food or are they just curious? Once there, one experimental peck would tell them there were goodies to be had, worth coming back for. For several weeks, I saw only chickadees there. Then the juncos began to come. Maybe they saw that the chickadees were making repeat visits and decided to check it out. They are considerably larger and much less acrobatic than chickadees, but they somewhat clumsily began to perch on top and reach down to the peanut-butter-laden holes. As time went on, they became more adept and more skillful at extracting several nice bites before losing their balance and fluttering down. Clearly they were learning how to exploit a new resource!

Occasionally other birds came too; a hairy woodpecker clung to the side of the feeder and reached quite easily over to the food source. A Steller’s jay sat on the deck railing, scoped out the situation, and flew straight at one of the gobs of peanut butter, snatching out a good mouthful on its way back to the railing. That worked, so it repeated the maneuver a couple of times. But it has not been seen again.

 

Dandelions

a surprisingly mysterious “weed”

Their cheery, bright yellow flower heads adorn the roadsides in late spring, before the compulsive mowing machines decapitate them. Foraging deer, bears, and human herbivores make use of their good nutrition. Bees and other insects visit the showy flower heads for nectar and pollen.

Dandelions seem to be everywhere in spring—roadsides, trailsides, some gardens, and even out on the rocky sea stacks. That widespread distribution led someone to ask if they are taking over the whole country. The simple answer is No. Dandelions are very good at colonizing open ground. They belong to a suite of weedy plants that specialize in colonizing disturbed sites—an ecological way of life known as ‘ruderal’. Their numerous air-borne plumed seeds waft about, sometimes for long distances, and a lucky few will land on disturbed ground such as roadsides, trailsides, and gardens (to the dismay of gardeners who have just weeded out the ‘last’ dandelion from their vegetable beds). So although a glance at our roadsides might make it seem like dandelions are taking over, unless all native habitats are disturbed by removing the original vegetation and rumpling the soil, dandelions are not going to take over everyplace.

The dandelions we see along the roads and trails probably belong to the species Taraxacum officinale, which originated in Eurasia and has become naturalized here. It has been on this continent for several hundred years, either brought over (intentionally or not) by immigrants from Europe or somehow by seeds blown over the ocean. In that time span, this dandelion has managed to spread all over North America in disturbed habitats.

When seeds are produced, the flower stem elongates, to raise the seed head above much of the surrounding vegetation. Each seed bears a long-stalked, puffy ‘parachute’ that catches any available breeze that might carry it to a new spot for colonization. Both the structure of the seed and parachute and the stem elongation are dispersal adaptations that aid the species’ ruderal strategy. But those adaptations are just part of the story.

Taraxacum officinale is generally known to be obligately asexual, producing seeds without pollination. That would mean that all offspring would be just like their mother—essentially forming a clone identical to her. The ability to reproduce asexually is another feature that helps to make the ruderal way of life successful—one plant can start a whole new population.

However, endless asexuality tends to reduce genetic diversity, which would eventually lead to considerable uniformity among all the individuals in a population. And that, in turn, as we know from what happens to genetically uniform crops when stricken by certain afflictions, can lead to catastrophic failure for the whole population. That somehow has not happened for dandelions, for various reasons. Mutations may occur, so that some offspring are a bit different from their mothers, and new asexual clones get started. Researchers have found that there is a further complication: the asexual dandelions are generally triploid (with three sets of chromosomes instead of the usual two sets) and during the process of seed formation there may be some recombination of genes between chromosomes, thus adding to the genetic diversity of the population. There is even a hint that pollination may (rarely) occur, such that some resulting seeds have been produced by sexual means, introducing still more genetic diversity to the population. In any case, as a result of mutation and occasional recombination, any population of dandelions is likely to be comprised of many clones.

All of that, however, leaves open a major evolutionary question about dandelion flowers. The function of flowers is sexual reproduction—attracting pollinators that convey pollen from one plant to another. But if the introduced dandelions reproduce without sex (at least almost always), why do they make such attractive floral displays? The bright yellow inflorescence is comprised of many small flowers, which offer nectar and pollen to insect visitors; production of flowers, pollen, and nectar is costly of energy. So why do it if reproduction is not sexual? It might be that dandelions engage in surreptitious sex more often than is thought to happen. Or perhaps the beautiful yellow inflorescence is a legacy of the past, reflecting the sexual reproductive habits of the ancestors of the present, clonal species.

In Southeast Alaska, besides the Eurasian dandelion, there are also two native species of dandelion that typically live in alpine and subalpine habitats; one of these is known to be obligately sexual, requiring pollen transfer between flowers. Bees and other flower-visiting insects might not discriminate between the native and the invasive species and may visit both in quick succession. Hand-pollination experiments have shown that pollen transferred from the invader to the sexually reproducing native species can result in some seed production, so genes from the invader may be assimilated by the native species. Such hybridization tends to obscure the distinction between the species. There is also a possibility that viable pollen from T. officinale could interfere with seed production in the native dandelion species (as has been reported for a similar situation in Japan).

The genetics of dandelions can be complex, and the taxonomy of the genus is quite confusing, with differences of opinion about which variants to call separate species. For now, suffice it to say that T. officinale is a highly successful ruderal, one that brightens our landscape with color.

Land and sea

ecological links both obvious and obscure

We often think of land and sea as totally separate entities, and this is commonly reflected in separate governmental jurisdictions. But the biological reality is that the two “entities” are very closely linked, and here in Southeast Alaska that connectedness is very evident.

Perhaps the most well-known ecological link between sea and land is told in the story of the ‘salmon forest’. Spawning salmon return to freshwater streams, bringing marine-derived nutrients (and pollutants) in their bodies. The spawners die or are eaten by predators such as bears, wolves, and eagles. Smaller consumers, including mink, otters, and some song birds, also nibble on the carcasses. The fish-eaters sometimes drag the carcasses into the forest and all the consumers deposit digested fish and the contained nutrients on the landscape, sometimes quite far from the streams. Flies and other insects lay eggs on the carcasses and aquatic insects have bountiful dinners; the flourishing abundances of insects are consumed by birds that contribute to the spread of nutrients over the landscape. These animals help fertilize the surrounding land.

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Crows catching sand lance in the intertidal. Photo by Bob Armstrong

But there are also many other channels by which marine-derived nutrients reach land. Less spectacular, perhaps, than the salmon runs and the attendant consumers, these other links make their contribution to the connection between sea and land. Lots of critters forage at the edge of the sea and then move up into the forest and meadows, where they deposit their digested dinners. Bears dig clams in muddy intertidal zones and gnaw barnacles off rocks. Bears, geese, and probably our beach marmots graze in the sedge meadows. Deer graze on sedges and intertidal plants. Ravens dig up sand lance and clams from the sediments. Eagles harvest herring and sand lance, and sometimes capture marine birds. Crows and ravens prey on sea urchins and small crabs and, during a eulachon run, these birds are known to store captured fish in grass tussocks and in trees.

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Black bear eating mussels and barnacles. Photo by Jos Bakker

It’s not all one-way, of course; it’s a two-way connectedness. The land has some major influences on the sea. Run-off from rain and snow-melt regularly carry the products of erosion, including sediment, fallen trees, and some dissolved nutrients, eventually to the sea. Glacier-fed streams send a rich supply of minerals and organic nutrients to the sea, feeding the plankton that feeds the herring and the whales and lots of other organisms.

Human activity can have some major effects too. A recent excursion to Hawk Inlet on Admiralty Island made this abundantly clear. This was a SEACC cruise, so the emphasis was on what the mining activities near the inlet are probably doing to things in the sea. Waste products from the mine are pumped out into the lower inlet, where some sink to the bottom and some are swirled about by the incoming and outgoing tides. Leachates from the tailings piles ooze downhill toward the beach. The situation there came to our attention when a harbor seal, harvested in that area and eaten by humans, was found to be heavily laden with toxic chemicals. Then the levels of various toxic metals (e.g., lead, selenium, and several others) in blue mussels, shrimp, crabs, clams, and cockles from the inlet were found to be several times higher than in other parts of Alaska. Perhaps not coincidentally, local herring spawning aggregations and littleneck clams have recently disappeared; so has a run of king salmon. The initial concern has been for humans that harvest wild food in this area.

However, if mussels, clams, shrimp, and cockles are picking up high levels of contaminants, it’s a sure thing that many other organisms are too, leading to ramifying consequences throughout the food chains. Contaminants, such as the toxic metals of direct concern here, get passed up the food chain, accumulating at higher and higher levels, until the top predators get really big doses. Even before the contaminant concentrations become lethal, sub-lethal levels (sometimes very small amounts) can change body chemistry in serious ways, including growth rates, behavior, and even the gender of some consumers. Such changes would be reflected in population sizes of the consumers and that, in turn, would affect the populations of their predators.

On this cruise, we saw some of the spectacular wildlife for which Southeast is famous. There were brown bears foraging on sedges in beach-side meadows. Dall’s porpoises dashed past the boat. Humpback whales cruised by and dove. A group of killer whales moseyed back and forth, sometimes making impressive vertical leaps out of the water. All of those species depend on resources that could be affected by contaminants. To take just one example: Killer whales are top predators that could accumulate high levels of contaminants from their prey. Resident killer whales eat fish, those that eat plankton directly and those that eat plankton-eaters, while transient killer whales eat marine mammals that eat fish that…

The other animals we observed could also be exposed to some level of potentially toxic mine effluent. Even though the effluent from the inlet presumably gets diluted in the larger channel, sometimes a little bit can have huge impacts. It is unlikely that anyone will look to see if that occurs, so it would be wiser to prevent it from happening in the first place.