Twice-told Tales

Juneau-style

I have borrowed this title from nineteenth-century writer Nathanial Hawthorne, because (like his book) this essay is mostly a collection of previously-reported short stories, bringing together a few of the special ones from our little expeditions over the years.

— Perseverance Trail: We were coming down the trail, just below the Horn (where two benches provide a view of Snowslide Gulch). Some distance ahead of us there appeared a large black lump, followed by two smaller black lumps, moving slowly up the trail. Ooooops! What now?! Steep cliff up on our right, steep cliff down on our left, and nowhere to go but back. So we quietly backed up a hundred yards or so to the Horn and waited. And there they came, mom and two cubs.

First we tried going up on the little rubble slope on the inside of the curve, to allow the bears plenty of room between us and the railing. But mom took one look at us on the rocks and turned around, heading back down the trail. Then she hesitated and looked back, as if she really wanted to continue upward. So we all scuttled into a corner of the fence behind the benches. Ah! Much better! The family came back uphill and sauntered past us—Mom completely calm and owning the trail, the kids a bit skittish. Everybody was well-behaved.

–Gustavus: We stopped to braid some stems of sweetgrass, just to see how it worked, with no ambitions to construct a basket. As we bent over our task, we heard thundering hoofbeats, getting rapidly closer. Turning around, we saw a galloping female moose, with a gangly little calf that managed to keep up with her. They were so intent on getting away from whatever startled them that they ignored us and passed by, barely thirty feet away, and off they went, full tilt.

–Granite Basin trail: We watched two bear cubs sliding down a snowy avalanche chute, tumbling head first and tail first. Then they climbed back up to do it again…and again. After watching her offspring, mom joined in the fun, and made several (somewhat more decorous) slides too.

–On a beach somewhere near Sitka: It’s always fun to find hermit crabs, sometimes a tiny one that can hide in the tip of a big whelk shell, or one wearing a wee periwinkle shell (seemingly uselessly) on the end of its abdomen. In the shallow water by this beach, we found dozens of hermit crabs scrabbling to and fro. They came in all sizes and there weren’t enough empty shells to go around. So there were battles going on everywhere, with one crab trying to pull another out of its shell. As soon as one extracted an owner and moved in, it was subject to attempted evictions. It didn’t seem to matter if the shell was the right size for the attacking crab…maybe any shell was better than none.

–North Douglas boat ramp: Crows had been foraging on mussels and other shellfish. We often see them do this, dropping their prey onto the beach in hopes of breaking the shell and exposing the fleshy interior. Very often, the substrate is too soft to be effective. But at the paved boat ramp, although it sometimes required two or three drops, the strategy worked very well—except when some of the crows chose to sit on the sidelines and wait for their hard-working companions to do the foraging and shell-dropping, then raced out to snitch the meat without doing the work.

–Cowee Meadows: As two of us strolled quietly on a bank above some lower ground, we suddenly heard some loud snorting and thrashing of brush from a thicket below us. Oh-oh! Our eyebrows and the hair on the backs of our necks went up. We couldn’t see the source of the ruckus, so we didn’t learn if the perpetrator was guarding a carcass or just feeling cranky, but we didn’t stay around to meet this annoyed beast and very carefully and discretely retreated down the trail.

–Berners Bay: A sizable troop of young sea lions approached our group of kayakers. They seemed to be very curious, eye-balling us with their heads raised up and talking loudly among themselves. They made several approaches, sometimes coming within twenty feet or so of a kayak. Another time, a humpback whale eased up to the surface right next to my kayak, close enough that I could have touched it. I’m sure the great beast knew I was there and was just visiting.

Another time there, right in front of the cabin, a humpback whale rose straight up with its mouth wide open, engulfing a dinner of herring. Escaping fish cascaded down from both sides of the mouth, a glittering stream (like liquid mercury, said one observer) in the sunshine.

–Glacier Bay: We were parked on a beach, sunning ourselves after a trip up the East Arm. The rising tide pushed some oystercatchers up the beach toward us…parents and two chicks. They stopped just a few feet in front of us and ignored us, giving us a great look at them, until we (unfortunately) had to move on.

–Gustavus: A friend and I had looked in several places here in Juneau for a particular kind of fern, a weird one called moonwort. We had failed and needed help. So we took the ferry, the good old LeConte, to Gustavus. We had to take the same ferry back to Juneau, so there was a short turn-around time. A naturalist friend met us and led us down the beach a few dozen yards, and said ‘There it is’. Finally we saw this elusive plant, and since then we have seen it and a related species in the Gustavus area and found it near the glacier visitor center. The ferry ride was good too!

–Eaglecrest: Plodding up from Hilda Meadows on snowshoes, we followed the trail of an otter all the way from Hilda Creek, up the hill along a Hilda tributary to the divide, thence to one of the sources of Fish Creek. That critter knew where it was going.

–Spaulding trail in late winter: A raven flew overhead and dropped something—thud—onto the snow next to us. It was a wad of moss and tiny twigs, but why would that make a thud? It was an old robin’s nest, mud-walled inside the moss-and-twig mix, and frozen solid. Now the question became—was that raven bombing us, as message, or just playing games?  

Solstice and More

a satisfying flower show

A trip to Cowee Meadows is always worth dealing with some broken or missing boards and a few flooded (sometimes ankle deep) sections of trail—a common occurrence after rains. Around the time of the summer solstice, the wild iris take over, with shades from pale lavender to deep, rich purple covering much of the meadow but leaving some room for buttercups, lupines, and the last shooting stars.

On the slightly higher ground, some stands of the wild rose were just starting to flower while others were almost finished. The big white inflorescences of cow parsnip made a good framework on the meadow edges. They were often occupied by dozens of tiny, slender flies, presumably sipping up nectar from the little flowers that comprised each inflorescence. Fireweed had yet to come, but the buds were promising.

A common flower, dotted in among all the others, is the chocolate lily or rice-root. The typical brownish flower smells fetid (unlike most flowers) and is pollinated by flies. The shades of brown vary: some are very dark, even reddish, some are mottled with green or yellow, and a very few are mostly yellow. Do the pollinators care?

June-19-Chocolate-lilies-kerry-howard
Photo by Kerry Howard

The sprawling shore plant called oysterleaf is widespread in northern latitudes. Its flowers are normally blue, but rarely white, according to two field guides, but we found white-flowered individuals to be quite common. The flower is insect-pollinated in some regions but is said to self-pollinate in others.

Few bees were flying on this day, but they are probably the principal pollinators of iris (as well as visiting many other flowers). A small insect might enter the flower but would not be big enough to contact the sexual parts. A bee crawls into the iris flower over a drooping petal-like sepal (the true petals are smaller and upright), passing under a narrow arm that bears the stigmatic surface where pollen is received, and then under a rod-shaped, pollen-producing stamen on its way to the nectar deep inside the flower. Cross-pollination would happen if the bee visited more than one flower, but the flowers are reported to be self-compatible, so if a bee happens to pick up some pollen on its way out of the flower and deposit some on the stigmatic surface, a seed might be produced that way.

Wild-Iris-with-bumblebee-entering-by-Bob-Armstrong
Photo by Bob Armstrong

An aquatic plant long known as Potentilla palustris (marsh cinquefoil) was always a bit of a puzzle to me, because most potentillas have yellow flowers and five petals but this one seemed so different, with its red- or purplish-flowers with six or seven petals. I’ve just learned that botanists have now recognized these and other differences by assigning this species to a different genus; it’s now Comarum palustre. The flowers are reported to have valuable pollen with lots of essential amino acids and lots of concentrated nectar, and they are visited by many kinds of insects.

In the muskeg at the start of the trail, we inspected the bog laurel flowers. When an insect (not too small) visits the flower and walks around on the petals of the open flower, the stamens usually spring up from their niches on the surface of the petals, potentially placing pollen on the insect. So we could tell which flowers had been visited. A visiting insect might also bring in some pollen from another flower, effecting pollination. Our inspection revealed that some aging flowers had no sprung stamens and presumably would not set fruit, but some fresher flowers had clearly been visited and might set fruit.

On the way through the woods down to the big meadow, the dainty little wintergreen called single delight or shy maiden presents its one little white flower to insect visitors, typically a bumblebee. A visiting bee rapidly shakes the anthers, which releases pollen for the bee to eat and collect. The flower is demurely held face-down as it awaits a bee, but if pollination occurs, the flower raises its head–no longer shy– as the fruit matures. We joke that it is now a brazen hussy. Here’s a link to that process.

All told, we found over sixty kinds of flowers, but we didn’t beat our record from a previous year of over seventy-five species. Still, not bad!

Cowee Meadows

a May expedition finds flowers and toadlets

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Photo by Deana Barajas

Several things combined, recently, to bring me a strong wave of nostalgia for the Midwest. I love the oak trees—their varied forms and leaf shapes and acorns. On top of that, my brother in Wisconsin regales me with tales and pictures of the birds that throng his feeders—orioles, goldfinches, rose-breasted grosbeaks, catbirds, and more—species that I’ve not seen for a long time. Then one of my old post-docs, in Chicago, wrote to me about all the spring flowers that grace the woodland floors—Dutchman’s breeches, bloodroot, spring beauty… Aaahh, I do miss all that!

However, on the last weekend in May, a bunch of regular Saturday hikers went out to Cowee Meadows. On the way down the trail, we enjoyed the many bog laurels and bog rosemary flowers in the muskeg, and we stopped to inspect the young bracken ferns for nectaries. Cowee Meadows is a place I like to visit several times as spring becomes summer, to see the seasonal development of the flower show. A couple of weeks ago, there were a few shooting stars, some buttercups and marsh marigolds, but little else. But now, the meadows were awash in color: lots of yellow buttercups, shooting stars in all shades of pink, joined now by tall blue lupines. Hidden under the taller plants were violets, starflowers, and the coming chocolate lilies. Even without the famous irises and the banks of roses, which will bloom in a week or two, this is a spectacular sight—hard to beat! Carpets of strawberry flowers out near the river weren’t bad, either, even though I never get there in time to harvest any of the fruits. Nostalgic feelings were successfully subdued.

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Photo by Louise Ketcheson

One of the most common plants in these meadows is the shrub called sweetgale (Myrica gale). It is very aromatic, and the nodules on the roots fix atmospheric nitrogen into a form usable by vegetation. The books say that sweetgale is typically dioecious—male and female on separate shrubs, but occasionally hermaphroditic—both sexes on one plant. Yet the shrubs all looked the same to me; where is the other sex? Then I read that, for unknown reasons, sweetgale males commonly outnumber the females by a big margin. So the many shrubs we see bearing small cone-like structures are presumably males. But if so, what do the females look like? Two field guides and a few official floras were no help at all; if they illustrated any flowering parts, it was the typical cones, and the verbal descriptions were unhelpful. Finally I discovered a website (thank you, Minnesota) that illustrated both male and female inflorescences.

It turns out that the rare female inflorescences look like small, red tufts along a twig. Knowing a characteristic that is useful in the field, we have now found two stands of female sweetgale shrubs and a few mixed-sex individuals in a population that is overwhelmingly male. Good to have that sorted out!

Another satisfying observation on this hike was seeing tiny toadlets making their way through thick tangles of herbage. I don’t know in which pond or slough they spent their time as tadpoles, but with patience, they can travel quite a distance once they have legs. One of these toadlets was crawling about on the upper beach, which is hardly a suitable place for a growing toad. Although it is tempting to catch them, we must remember that if we have insect repellent on our hands, it can poison them through their skin. And, in any case, it is illegal to hold, transport, and release them. Better to just observe and protect them!

When I got home, there was fun at my bird feeders. When the pushy jay and the big hairy woodpecker aren’t there, chickadees, nuthatches, and juncos use the peanut butter feeders daily. I started watching more closely as the three smaller birds pecked at the peanut butter lumps on the feeder. Peck and gobble, peck-peck and gobble. But the last peck gets a little gobbet that doesn’t disappear into the inside of the bill. A small wad of peanut butter is carried off into the woods, and I’m betting that it goes to a chick.

Insect vision

and what they see in flowers

Most adult insects have two kinds of eyes. Small “ocelli” on various parts of the head are light-sensitive but are thought not to make good images. The two large “compound eyes” that are used for finding food or mates or landing sites are actually composed of numerous single light receptors called ommatidia. There are thousands of ommatidia in the compound eyes of some insects, such as dragonflies, but only a few in ants. In day-active insects, each ommatidium typically forms its own image, so what a compound eye sees is a mosaic. A mosaic isn’t as clear as the single image made by a vertebrate eye, but compound eyes are very good at detecting motion.

Day-active insects typically have good color vision, although they have little sensitivity to red. Most of these insects have two peaks of light sensitivity, one in the green-yellow range of wavelengths, the other in blue and ultraviolet (UV). But honeybees, bumblebees, and most butterflies generally have three peaks of light sensitivity: for yellow, blue-violet, and UV.

Many of us are familiar with hummingbirds’ preferences for red. Insect pollinators also have color preferences —bees for blue, hoverflies for yellow. But they are certainly not restricted to those colors and may visit many kinds of flowers, using color as one means of telling them apart, so they can learn to avoid those offering little reward.

Showy flowers with pretty petals and other ornamentation evolved to attract pollinators; they are part of a sexual display, making use of insect color-vision in achieving pollination. The wide array of colors and color patterns of flowers (along with size and shape) helps insects to discriminate among flower species and concentrate their visits on those that offer the best access to food rewards (exceptions include flowers that are false advertisers, as discussed in a previous essay). From the flowering plant’s point of view, concentrating an insect’s visits increases the probability that pollen is transferred among plants of its own species and less is wasted on some other kind of flower, with no reproduction accomplished.

Humans can’t see UV, so flowers look quite different to us than to a bee or butterfly. Some flowers have particular UV markings (which we can ‘see’ only with special equipment) that help identify the flower or perhaps guide an insect visitor to the right place and position to obtain nectar and effect pollination. Here are some local examples:

Silverweed (Potentilla anserina) is common on our wetlands, yellow marsh marigold (Caltha palustris) grows in some sloughs and slow creeks, and large-leaved avens (Geum macrophyllum) grows along many trails. All three have flowers that are yellow to human eyes. And all three are reported to have flower centers that absorb UV and look dark, in contrast to the outer parts of the petals, which reflect UV and are bright. Many bee-pollinated yellow flowers are said to have this arrangement, with UV absorbing centers and UV-reflecting peripheries.

The blue harebell (Campanula rotundifolia) reflects UV on the female sexual parts (pistil and stigma). Field chickweed (Cerastium arvense) has white flowers that reflect UV strongly. The yellow monkey-flower (Mimulus guttatus) has two different life-histories: some are perennial and some are annual, and the UV markings on their flowers differ too. Bees are reported to discriminate against whichever pattern is unfamiliar to them.

Long-leaf sundew (Drosera longifolia) that grows in some of our muskegs has white flowers. But the petals and sexual parts absorb UV while the nectaries are strongly reflective of UV rays. Interestingly, in this insectivorous plant, which traps bugs on its leaves, the leaf blade absorbs UV but the sticky drops on the bug-catching tentacles have strong UV reflectance, making a big contrast.

Among the orchids, the forest-dwelling species known (for some strange reason) as rattlesnake plantain (Goodyera oblongifolia) has white flowers and is bee-pollinated. But the forward-projecting, cup-shaped middle petal (called the lip) is reported to reflect UV as a bright yellow-green. Yellow ladyslippers (Cypripedium parviflorum) are said to have very UV-reflective tissue around the opening of the lip (or “slipper”), at least in some populations. UV patterns of calypso orchids in Southeast are now being investigated. (Thanks to Marlin Bowles for digging up the information on orchids.)

Some of our non-native flowers have UV patterns too. Dandelions absorb UV in the center and reflect UV on the outer fringe of petals. The little weed called herb robert (Geranium robertianum) has a dark-centered, UV-absorbing pink flower. Orange hawkweed (Hieracium aurantiacum) has orange-red flowers that are said to reflect a checkered pattern.

Many other local species have apparently not been examined for UV-absorbing and -reflecting patterns. There’s a photography project waiting for someone!

Exactly how the UV patterns work in attracting insects or in focusing an insect visitor’s attention on the nectar source and sexual parts of the flower is not well documented, it seems. Insects may sometimes be indifferent to them or attentive only in certain conditions. More research is needed.

Fun at Home

looking out the windows

I love to walk our trails, just to see what I can see. But sometimes there’s a lot to see in my front yard and pond. Then I wear a path from window to window (with side trips to the fridge and tea kettle). This spring has provided some home-based fun.

The shenanigans of the mallards are an annual happening. The ducks start to visit the pond soon after ice-out. Pairs sort themselves out and by late May mama ducks start to bring their tiny ducklings for an occasional visit. This year there were several brood of eight or nine and one brood of just one duckling.

The littlest ones have a hard time jumping up to join mama on the bank for a rest. They zip back and forth in front of her and make lots of futile little leaps. The female often tries several spots before finding one they can all master. Sometimes only part of a brood makes the jump and the rest have to find access at some distance and make a small overland trek. When ducklings are small, the mother broods them, making herself as broad as possible to cover them all, although even then a few heads and tails poke out from under her.

The unpaired males that have already fathered these broods are hanging about, all revved up and looking for more action. They harass any late-forming pairs and even mothers with babies, causing lots of fuss and flapping. The female with one offspring was persistently pursued, driving her to protest continually and even leave the pond several times. If I opened the windows, I could hear the little one peeping in apparent distress.

A flotilla of visiting ducklings is probably what brought an eagle down to march along the bank, eyeing one brood with malevolent intent. (Yes, I know, eagles have to eat too.) A swoop or two over the water failed, as the brood scooted for cover, and the eagle left, still hungry.

Juvenile juncos had been chip-chipping in the woods along various trails since mid-May. Here at home, there were well-fledged juveniles, of two separate families, by the first week of June, quite able to pick up seeds for themselves but often waiting for dad to deliver. It was the male juncos that stuffed the juveniles with peanut butter and seeds, leading me to suspect that the females were back on eggs again, for second broods. (They can do three or four a year.) The juveniles tried the peanut butter feeder occasionally but looked like they needed some practice, and they preferred to wait for dad.

A male hairy woodpecker made occasional visits to peanut butter and suet, but by mid-June his visits were quite frequent. He hacked out big chunks of suet and carried them off, leaving crumbs for the little birds to pick up. He would swallow several bits of peanut butter but carry away one last load in his bill. So I knew he had a family. And finally, a big, well-feathered fledgling joined his father on the deck railing and begged for peanut butter. I wondered if the mother was tending another young one somewhere.

The chickadees were feeding big kids too. And a great treat was seeing the whole family of nuthatches crowding together on a small block of suet. Two sleek fledglings chipped off bits of suet for themselves, but were also happy to have chunks delivered by the parents.

A bear came to eat horsetail in my front yard. They do this every year. Often they lie down flat and just scoop in the green stuff. This guy got up and wandered up toward the house, sniffing and sniffing, then stood under the edge of the deck to sniff some more. No doubt the aroma of peanut butter was in the air. Before I could say oh-oh, the bear shot up a nearby tree like lightning, just a black blur. It went up above the roof level, out of sight. Now, I’m not too enthusiastic about a bear on my roof (or deck). I raced outside to check the roof, but by then it was already down and gone. The tree was just a bit too far away from roof and deck. But just in case, I have moved the alluring feeder to the other end of the deck; the birds are getting used to the new arrangement.

One more bear story: A medium-size cinnamon bear came and foraged on horsetail. That gave me time to see that she looked like she’d worn a collar for a long time because her fur was very worn in a circle around the neck, but she had no visible ear tags. Eventually, she started to wander out of sight. Immediately, an alder tree across the pond gave a violent shudder, and a massive glossy-black bear suddenly appeared in the yard. He chomped a couple of horsetails but was much more interested in her, and he followed her off into the neighbors’ yard. It’s that time of year for bears!

Long Distance Migrations

by individuals, and across generations

Many animals make regular seasonal migrations. Some are quite short: I’m remembering the snakes that hibernated in deep crevices in Midwestern bluffs and came down to nearby swamps and floodplains for the summer, going back to the bluffs for the winter.

At the other end of the spectrum are some extremely long migration distances (note that the following distance estimates take little or no account of detours to follow shorelines or concentrations of prey, etc.). The Arctic tern is generally considered to be the champion, migrating from Arctic to Antarctic and back every year, an annual round-trip distance of perhaps as much as 25,000 miles.

But other species are also impressive: the bar-tailed godwit flies nonstop (!) from Alaska to winter in New Zealand, a distance of almost 8000 miles in eight days; on the way back, they take a longer route and stop over to fatten up in the Yellow Sea (between China and Korea) –in total, a round trip of over 18,000 miles. Aleutian terns go from Alaska to Indonesia and south-east Asia for the winter, covering perhaps 20,000 miles each year. The little shorebirds called sanderlings breed in the High Arctic; some of them fly to Tierra del Fuego for the winter, and back again in spring, a round-trip of close to 20,000 miles.

Some seabirds that nest in the southern oceans go north for their winter. Sooty shearwaters fly from their nesting areas in the Falklands and Tierra del Fuego to Arctic waters near Norway and back again, over 17,000 miles in the Atlantic (round trip); in the Pacific, they fly even farther, from near New Zealand to the Gulf of Alaska. Short-tailed shearwaters fly even farther: they breed near Tasmania and migrate to the North Pacific; some even go through the Bering Strait to the Arctic Ocean.

All of these critters are relatively long-lived, with lifespans measured in years or decades, and may make those journeys many times in their lifetime. And in most cases, they can feed along the way.

There are long-distance migrants among the insects too, but they are relatively short-lived, with lifespans (for active adults) measured in days or weeks, and they do it differently. A single individual does not make the round-trip journey; instead, they breed along the way and the next generations take over the route.

The best-known example in North America is the monarch butterfly. Monarchs that are born and raised in the eastern U.S. and southern Canada migrate to special forests in northern Mexico for the winter (occasionally some go to Florida or other places in southeastern U.S.). When spring comes, they start north again, but they stop to breed along the way. It takes two or three weeks for each generation of eggs and caterpillars to mature into the migrating adults. That new generation continues northward, and again they stop to breed. It may take three or four generations for monarchs to reach their northern-most range, where they produce the long-distance travelers to Mexico. There is also a smaller population of monarchs west of the Rockies; it migrates to California and northwestern Mexico. But monarchs are in deep trouble, due to habitat changes that reduced the availability of milkweed plants on which the larvae feed and to serious deforestation in their particular overwintering sites in Mexico.

Painted lady butterflies do something similar. From wintering areas in Mexico they migrate northward in multiple generations to the Canadian border; the European populations migrate from south of the Sahara Desert in Africa to northern Europe and even Iceland, making several breeding stops on the way. Red admiral butterflies winter in southern U. S. or southern Europe and commonly migrate north in spring, but shorter distances than the painted ladies.

Painted-Lady-Butterfly-by-Bob-Armstrong
Painted Lady. Photo by Bob Armstrong

Perhaps surprisingly, some dragonflies are good migrants too. In North America, the big, beautiful green darner had a complicated arrangement, with a roundtrip distance of nine hundred miles or so. It migrates from wintering areas in southeastern U. S., the Caribbean, and Mexico as far as southeastern Canada. One generation makes this great leap and breeds. Some of the resulting offspring stay there, overwintering as larvae in ponds. Others migrate south to the wintering areas, where they reproduce, and these adults are residents in the wintering area, but their offspring will be the next year’s northward migrants.

An even more far-traveling dragonfly is called the globe skimmer. It is widely distributed on many continents and apparently moves around a lot; they have been recorded flying over the Himalayas. But even better: some of them fly over the Indian Ocean from India to East Africa. Some of this over-four-thousand mile flight seems to be nonstop, although the dragonflies might stop to breed if they happen to find an island with suitable conditions. After breeding in Africa, they go back.

That’s not the end of amazing insect migrations. Two kinds of hoverflies, less than a centimeter long, migrate from the European continent to Britain. There they pollinate many kinds of flowers and their larvae gobble up aphids. There may be several generations in a summer. Then the last of the summer-produced generation flies back to the mainland. From there, one species heads to North Africa to spend the winter and make a new northbound generation.

There is surely a lot more to be learned about insect migrations! For instance, how do they navigate? There are likely to be more of such interesting migrations, yet to be discovered.

Bog plants and bird feeder

there are things to wonder about everywhere!

Just after mid-May, the alders and cottonwoods were suddenly (so it seemed) in full leaf, the fresh, bright green a pleasant contrast with the dark conifers. Even the blueberries and other understory shrubs made a new layer of green above the mosses. Hermit thrushes added their welcome voices to the canopy and fox sparrows tuned up in the thickets.

Early in the fourth week of May, I poked around in some low-elevation bogs (muskegs). Several species were beginning to flower—bog blueberry with deep pink buds and young flowers, bog laurel with broad, pink petals, and bog rosemary with small, pink flowers. The white flowers of trailing raspberry (or five-leaf bramble) starred the mosses under the scattered trees. The distinctive few-flowered sedge was surprisingly colorful, with vibrant green leaves and a yellowish inflorescence. An unidentified sedge with pale green leaves was common but only a few were yet in flower. Labrador tea, lupines, and buckbean were budding. Round-leaf sundews were still just tiny rosettes, their sticky, insect-catching leaves glittering in the sun.

I found a single specimen of a weird little herb (Geocaulon lividum) sometimes called bastard toadflax , but also known as pumpkinberry or timberberry or other common names. Seldom common, it is nevertheless widely distributed across northern North America. It’s a hemiparasite—getting some of its nutrition from its green leaves and some by parasitizing the roots of other plants. It’s not fussy about its host plants; it parasitizes anything and everything from pine trees and blueberry bushes to asters and horsetails to sedges and grasses and even others of its own species.

Photo by David Bergeson

This plant makes only a few small inflorescences; each inflorescence typically has three flowers, usually one female flower in the middle, flanked by two male flowers that drop off eventually. The open flowers are dull yellowish-green with purple marks and I’m guessing they are pollinated by flies or beetles. The orange-red fruits are few, each one with a single seed. Very little seems to be known about seed germination and dispersal. But the seeds are sometimes harvested and cached by Arctic ground squirrels up north and presumably eaten, perhaps sometimes dispersed, by other rodents. It seems likely that birds would take the colorful, fleshy fruit and potentially disperse the seeds.

The fruit has plenty of sugar in it, especially when fully ripe at the end of the season (usually late summer). Estimates of sugar content found that each fruit has about thirty milligrams of sugar, which is more than blueberries or most other fruits in Southeast. Despite the sugar content, the fruit is reported to be just barely edible or tasteless to humans.

Here at home, there’s lots of action on the pond. As many as five male mallards gather, all good pals now that their lady friends are incubating eggs. That changes, though, when one late-nesting (or re-nesting) couple shows up, and the male of that pair harasses the peaceful gang, keeping them well away from his mate.

The bird feeders are busy places. Siskins, juncos, chickadees, and nuthatches visit the seed feeder that hangs over the pond. A jay slams into the side of that feeder, knocking cascades of seeds down for the ducks.

The peanut-butter feeders are the most fun. They’re just little blocks of wood with pits drilled into them, to hold a small gob of peanut butter. Chickadees and nuthatches went crazy over them, but now the juncos almost monopolize them. Juncos are not nearly as agile as the smaller birds, but they cling and stretch (and often fall off) to get a nice bite. Sometimes they perch on the deck railing and fly up to stab and grab out a bill-full.

The jay does the stab-and-grab method too, but he’s a bit rougher, hitting one of the smaller peanut-butter feeders hard enough to knock it off its hanger, so it fell to the deck and broke into four pieces. But that’s not the end of the jay’s mischief. It has started to come to the deck railing to scarf up leftover bits of cat food that I commonly leave out for a raven. One day that jay made off with a whole set of chicken ribs, a load that it could barely carry to a nearby tree. The raven was out of luck again.

Columbia Spotted Frogs

a glimpse of some little-known local amphibians

A friend told me about a place where frogs were breeding, so I went to look. Not a frog in sight, except for a pair of legs disappearing under an algal mat. But I went back a few hours later, when the day had warmed up, and there they were—at least a dozen of them. The males were singing, if one can call it that: the ‘song’ is a series of grunts, and different males sang on slightly different pitches. Occasionally an eager male approached another frog and tried to grab it from behind, which is the usual position for fertilizing eggs as they emerge from a female. Males have sturdy forearms and strong thumbs for the purpose of holding a female in an embrace called amplexus. But as I watched, the male was kicked off by the presumed female; either she wasn’t ready to mate or ‘she’ was really another ‘he’.

Those singing frogs are probably Columbia spotted frogs, which are native to Southeast Alaska, occurring chiefly in the transboundary river valleys. How they got to Juneau is not known—possibly with help from humans. However, in recent years, they have been seen in several places in the Mendenhall Valley and, a few years ago, specimens were sent to an expert for genetic analysis, which determined the species identity.

Columbia-spotted-frog-Kerry-howard
Photo by Kerry Howard

Columbia spotted frogs hibernate in ponds, springs, beaver dams, and under stream cut-banks where it doesn’t freeze and moisture has adequate dissolved oxygen for them to breathe (through the skin). However, they are not dormant in winter; they can move around, sometimes several meters underwater to a new wintering spot. Come spring, males emerge first; they (unusual for amphibians) then choose an egg-laying site in warm, shallow water. Later-emerging females (up to 100mm long) find the males’ chosen sites. They are larger than males (up to about 70mm) and can lay hundreds of eggs in a globular mass.

Each fertilized egg is surrounded by two jelly layers and takes up to three weeks to hatch; the time is shorter when the water is warm. The tadpoles are about eight millimeters long when they hatch. They can grow up to ninety millimeters (total length) by the time they lose their tails, grow legs, and look like little frogs, but some transform at smaller sizes. If conditions are right, they may transform in their first summer, but otherwise they can hibernate until the next year. The froglets grow but don’t become sexually mature for two to six years, depending on conditions. Males mature at an earlier age than females but have shorter lives, on average. Adults can live for several years: in some regions up to about twelve years for females and ten years for males, but elsewhere just seven years for females and three for males.

The frogs feed primarily on a variety of small insects but also eat snails, worms, and (rarely) a tadpole. Tadpoles are typically herbivorous: they scrape vegetation and filter the fragments; they also filter detritus and occasionally scrape a dying tadpole.

Spotted frogs show a fair degree of site fidelity for breeding and hibernation. They can travel quite long distances overland, from a hibernation site to a breeding site. Then they may move to a summer feeding site and eventually back to a hibernation site. Travels up to about six hundred meters long have been recorded.

This species, along with other amphibians in North America, is at risk from a lethal fungus infection that has decimated other amphibian populations. Spotted frogs (and our western toads, wood frogs, and other native amphibians) are legally protected: one is not allowed to “hold, transport, or release” them without a permit from ADFG.

Deception in animals and plants

the uses of trickery

Deception is widespread in the animal kingdom. Caterpillars may look like twigs and crabs may cover their shells with a mini-forest of algae, to fool their predators. Fake eyespots on moth wings or the rear ends of caterpillars deflect predatory attacks from real heads. A predator may simply hide itself, in ambush, conveying no apparent threat.

Sometimes the fakery involves decision-making on a more immediate and individual level. For instance, a defensive animal may puff itself up to look bigger and perhaps more dangerous than it really is. Or a chimpanzee, a titmouse, or a jay might emit a fake danger call when no predator is near, just to spook other animals away from a food source.

Deliberate deceitfulness is well-known among animals that cache food, particularly if another critter observes their caching behavior. The trickery goes beyond merely spacing the caches more widely, as chickadees do, or going behind some visual obstacle to make a cache. Gray squirrels make fake (empty) caches if they are watched by another squirrel. Ravens (and other corvids) are even more duplicitous, if they are observed by another raven: A bird with a food item caches the item but surreptitiously sneaks it out and goes away to stash it elsewhere, while the observing bird visits the now-empty cache site. And it matters just who the observer is: a stranger or known pilferer may be treated much more suspiciously than a mate or a buddy!

In the plant kingdom, a wide array of plants uses deceitful flowers to attract pollinators. A local example is the Calypso orchid, which looks and smells like food to a bee, but in fact offers no reward at all; thus it is visited mostly by naïve bees that lack experience.

There are almost thirty thousand species of orchids, mostly pollinated by bees and wasps (some by flies and other flower visitors) and researchers estimate that about a third of them use some form of floral deception to achieve pollination. Food deception, as in Calypso, is common, fooling various wasps and flies, for example. Sometimes an orchid flower looks or smells like a female wasp or bee, and males get revved up and try to copulate with the flower, accomplishing pollination in the process. Still others look like male bees, and when the flowers sway in the wind, they are attacked aggressively by other male bees. Some Old-World species emit the aroma of alarmed aphids, which attracts female aphid-eating hoverflies to a potential egg-laying site; but it’s a fake—if eggs are laid, there are no aphids for the larvae to eat. In the meantime, hoverflies can be good pollinators. And then there are orchids that resemble prey and are attacked by female wasps that are foraging food for their offspring.

Pollination by deception has evolved many times in the plant kingdom, occurring in many evolutionary lineages (but fewer in total than all the deceptive orchids). Here are some non-orchid examples. A South American species in the potato family attracts small flies with the odor of decaying carrion that smells like a place for these flies to lay their eggs, although it is not. A Middle Eastern member of the arum family emits the fragrance of dung and similarly deceives flies that are looking for a brood site. A Chinese member of the dogbane family uses a pitfall trap to capture certain little flies, using a scent that suggests a predator (such as a spider) has captured an insect. These flies are ‘kleptoparasites’, making their living by stealing prey from predators. They are drawn to the flower by the scent of the spider’s prey and fall into the trap. As they scrabble around in the trap, they pollinate the flower. In a few days, the trap collapses and allows the fly to escape and go to another plant with its load of pollen.

Fungus gnats are the typical pollinators of jack-in-the-pulpit, attracted by the smell of spongy, fungus-like tissue that seems to offer food for gnat larvae (but it’s a fake). Jack-in-the-pulpit plants bear many small flowers on a spike-like inflorescence that is surrounded by a vase of vegetative tissue (a type of pitfall trap). They usually produce male and female flowers on separate plants. Both draw in the gnats; in male flowers the gnats are temporarily trapped by tissues around the inflorescence but ultimately escape through an exit hole at the bottom of the trap. When they then visit a female flower, they carry pollen, achieve pollination, but cannot escape the trap.

That’s just a wee sample of the nefarious ways that flowering plants fool a variety of insects into pollinating the flowers. Clearly, if all the visiting insects were fooled, populations of the relevant insects would die out—they’d waste time and energy on profitless activity, or starve, or their larvae would die. So some pollinators learn to avoid the frauds (as apparently happens for Calypso) or some members of the species that can be fooled are not so foolish.

Seeing UV

some vertebrates can do it

First, some basics: Vision depends on light, which comes in a spectrum of wavelengths, ranging from very long to very short. Vertebrate eyes have two kinds of light receptors in the retina at the back of the eye: Rods, which are sensitive at low light levels, and cones, which are stimulated at higher light levels and function in color vision.

Humans (and a few other mammals) have three types of cones; each type is receptive to a different range of wavelengths with peak sensitivity in the middle of the range. One type of cone deals with long wavelengths toward the red end of (what we call) the visible spectrum; other cones are sensitive to medium-long wavelengths in the middle part of the spectrum. The third type of cone is sensitive to short wavelengths, in the blue-violet end of the spectrum. Still shorter wavelengths, outside of the normal human visible spectrum, we call ultraviolet (UV). Humans and some other mammals have cones that are slightly sensitive to UV light, but the lenses filter it out.

However, lots of birds, fish, and reptiles have a fourth kind of cone that is UV-sensitive. Even a few mammals (e.g., some rodents and bats) can see UV light quite well. Furthermore, some mammals have lenses that don’t filter UV wavelengths, so they can use UV to some extent– examples include hedgehogs, dogs, cats, and ferrets, among others. Day-hunting snakes have lenses that block UV wavelengths, but night-hunting snakes have lenses that transmit UV. For these animals, just little extra light might enhance vision in some conditions.

I’d love to be able to present a survey of all the vertebrates, not only about who has UV vision, but also to find possible correlations of UV sensitivity with the ecology, behavior, and evolutionary history of the species. But such a systematic survey does not exist. Part of the problem lies in the complexity of what determines the sensitivity; several factors are involved. The animal must possess the visual receptor cells (typically cones). Those cones must also be functional; that is, they must not be turned off by genetic mutations. And the UV wavelength must actually reach the retina, not filtered out by lens, cornea, or other structures. Apparently only seldom have enough of those features been measured in enough animals allow a wide search for correlations with ecology, behavior, and evolutionary history.

There is still a further question: if an animal can see UV, how is it useful to the animal? This is often difficult to determine, and suggestions outnumber the answers. Here are a few bits and pieces:

UV sensitivity may be useful in foraging: Several studies have suggested that birds of prey that hunt small mammals may key in on trails left by the mammals as they scent-mark with reflective urine, although another study showed that vole urine is not very reflective in the UV range. It is possible that UV-sensitivity helps locate ripe fruits or insect prey because the UV reflectance of fruit and some insects differs from that of background leaves. But how often this works in the natural world is uncertain. Hummingbirds can see in the UV range. Many flowers either reflect or absorb UV, and hummers may use that ability to discriminate among flowers that they might visit and pollinate.

Among bats, a mutation causing loss of functional short-wave light sensitivity is found in nocturnal species that commonly roost in caves and echo-locate, using sonar to navigate and capture prey. Researchers suggest that perhaps using sonar pre-empts brain space otherwise used for UV perception. However, the correlation is not so clear, because the loss also occurs in fruit bats, which roost in trees and do not echolocate.

 

Decent data are more available for the use of UV reflectance and sensitivity in social situations in birds, fishes, and reptiles with good color vision. For example, male mountain bluebirds have more UV-reflective plumage than females, and males that reflect more UV are more successful in mating and siring offspring. Similarly, female sticklebacks and guppies perceive UV and prefer to associate with males that have good UV reflectance. Another study showed that lizards living in light, UV-rich habitats have social displays that convey signals in the UV range, while those in dark habitats do not.

I’ve left mention of amphibians to the end, because that story gets more complicated. It seems that many amphibians can see color in the dark. They have two kinds of rods (sensitive at low light levels) in addition to cones; some of those rods are UV sensitive. Could that be true of some other vertebrates too?

This leaves UV vision in insects and spiders and other invertebrates for another story (maybe).