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Learning to See

Willingness, mindfulness, focus, and detective work

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

Houses for mites?

an intriguing relationship

One July day I was moseying along a streambank, looking at the alders. Both red and Sitka alders grew there, but I was focused on the Sitka alders; I examined many leaves and put a few into a plastic bag to take home. A passer-by asked if I intended to eat them. Well, no, to my knowledge, humans don’t eat alder leaves—I planned to inspect the under-surfaces of the leaves with a dissecting microscope in my study.

Whatever for?? I suspect that most of my hiker friends already think I’m a bit nuts, with my interest in the composition of bear scats, the details of floral structures, the strange habits of slime molds, an unusual bird song, a skanky salmon carcass squirming with maggots, or other arcane natural history matters that often make me stop along a trail. A concern with the underside of alder leaves would probably clinch their opinions. Oh well….

I am interested in Sitka alder leaves because some of them have little tufts of hairs in the vein axils, where the side veins come off the midrib. On many other woody species in North America, including some maples, oaks, cherries, and grapes, tiny structures in vein axils (usually tufts of hair in North America but often pits or pockets elsewhere) serve as domiciles for mites. They are called domatia (singular = domatium), which means ‘houses’. And they serve the functions of a house: mites retreat to them for shelter from environmental extremes and predators, to lay eggs, to defecate, and to molt (leaving their exoskeletons there). Years ago, by surveying many leaves of many species in the eastern forests of North America, we found that at least twenty-five percent of domatia (and often fifty percent) in most species showed signs of mite occupancy. Similar occupancy rates were also found in foliar domatia in many other parts of the world.

Sitka-alder-Domatia 2 Carol Griswold

It is important to recognize that domatia are made naturally by the plant itself; they are often visible in the developing leaf bud. They are not galls, which are induced by the activities of insects or mites. So it is reasonable to ask if they serve a purpose and what that purpose might be.

Almost all of the mites we (and others) found in the domatia were potentially beneficial to the leaves and the plants that made them. Most of the mites were predatory–eating other mites or small insects–or fungus-eating–consuming molds and mildews and fungal filaments. Many studies have shown that the abundance of such beneficial mites is higher on leaves with domatia than on leaves without domatia. So the observations clearly suggest that this is a mutualistic relationship, in which both participants benefit: mites get housing in the domatia and plants get protection of their leaves.

The idea that the mite/domatia relationship is mutualistic dates back to 1887, when a Swedish scientist first looked at this. A few biologists accepted the idea without further investigation. But as is often the case with any new idea, the mainline scientists of The Establishment viewed the idea with scoffing, scorn, and rejection. Someone even went so far as to suggest that domatia occurred on leaves for the benefit of plant taxonomists, because they turned out to be useful in identifying species.

Such foolishness aside, a few experiments more than a hundred years later eventually showed that leaf damage is less when mites occupy the houses and forage over the leaf surfaces. Further study revealed that associations of mites with foliar domatia go back many millions of years, showing up in fossils. By now, leaf domatia are known from woody plants in most major taxonomic groups all around the world.

So—back to my Sitka alder leaves: I wanted to know if there were mites in those domatia too. I looked at ten mature domatia-bearing leaves from each of five locations in Juneau, counted the domatia and inspected them for evidence of mites. In over four hundred domatia, I found only four mites and one possible mite egg.

In the course of searching many alder leaves for domatia, I also found that leaves on many branches and trees had no domatia at all. In short, development of foliar domatia is sporadic in Sitka alders and mite occupancy is apparently very low. It takes a while for mite populations to develop on new leaves each year, so possibly a census of domatia in August would show a higher occupancy rate than in July, although that begs the question of what good it might do to protect leaves so close to the time when they turn brown and fall off. Maybe the summer season here is simply too short to allow time for a good population build-up of beneficial mites? Furthermore, considerations of mite population levels do not address the question of why domatia occur so sporadically on these leaves.

Perhaps evolution is in process of eliminating useless domatia from Sitka alders…or, contrarily, increasing their potentially useful occurrence on that species. Would on-going climate change affect the outcome? More questions than answers, once again!

Flowery fun in Gustavus

an orchid show, and other floral delights

Lady’s slipper orchids are sometimes called moccasin flowers, referring to the shoe-like shape of the flower. One of the petals is modified to form an oval pouch with an opening on top. The edges of the pouch are rolled inward. A small shield-like structure hangs down into the back of the pouch and behind the shield are the sex organs. The flower offers no nectar to visitors, but at least some species have an attractive aroma.

Bees that visit these flowers enter the pouch, but the rolled-in edges keep them from crawling out. So, once in the pouch, the bees are obliged to crawl up behind the shield, in order to get out again. In doing so, they pass very close to the pollen-receiving stigma, leaving pollen from previously visited flowers, and the pollen-bearing stamens, picking up pollen on their bodies to carry to another flower. A very elaborate system for creating the next generation of lady’s slippers.

After pollination, thousands of dust-like seeds are produced. They are so small that they contain no nutrition for a developing embryo (this is true of orchids in general). Lacking a source of nutrition, the seeds have to rely on forming an association with certain fungi (mycorrhizae), in order to germinate and grow. Lady’s slippers are slow growing and take several years to reach the flowering stage.

There are dozens of species of lady’s slippers in North American and Eurasia. They belong to the genus Cypripedium. This name is derived from some ancient Greek words. Cypris is an old name for Aphrodite (a.k.a. Venus in Latin), the goddess of love and beauty. The ‘ped’ part of the name refers to foot or footwear, sometimes rendered as ‘sandal’. So Cypris/Aphrodite/Venus has a rather large collection of sandals in her wardrobe!

Lady’s slippers were familiar to me, from years spent in the Midwest, but I have never seen them in Juneau. So one of my hopes for a recent Gustavus trip was seeing these in bloom. We’d seen their leaves occasionally in the past, but the plants were not then in flower. On this June trip, with the help of a knowledgeable naturalist there, we located clusters of three species of Cypripedium. There was a large-flowered white one (C. montanum, or mountain lady’s slipper). A small-flowered, round white one with some brownish spots is called C. passerinum (sparrrow’s egg or northern lady’s slipper). A yellow-flowered species has often been classified as a subspecies of C. calceolus, but more recently botanists seem to consider it to be a separate species, C. parviflorum, the small yellow lady’s slipper.

June 22 Cypripedium passerinum Sparrow Egg orchid 2 resize
Cypripedium passerinum, sparrow’s egg lady’s slipper. Photo by Kerry Howard

Lady’s slippers and many other showy orchids are often collected from the wild by willful gardeners. But this practice has led to the near-extinction of some species. The slow-growing habit, low levels of pollination and seed set, and the need for mycorrhizal fungi make recovery of exploited populations slow and difficult. So these plants should never be harvested from their native habitats.

June 22 Cypripedium Yellow Orchid 2 resize
Cypripedium parviflorum, small yellow lady’s slipper. Photo by Kerry Howard

We found other orchids too. Tiny twayblades are much more common in Gustavus than in Juneau. They are pollinated by minute flies and wasps, as Darwin documented long ago. Coralroots and so-called rattlesnake plantain are common in Juneau as well as Gustavus.

Orchids were not the only flower show in town, however. Lupines created hills of blue on the beach dunes. Cow parsnips and buttercups brightened beachside meadows. Roses and irises added splashes of color. One meadow was thoroughly decorated with the small white inflorescences of Tofieldia, which is easier to say than the ponderous common name of sticky false asphodel. Sticky it is—the stem sometimes captures tiny insects. Apparently, some botanists thought the inflorescence resembled the European asphodel, which in Greek mythology grew in the meadows where the souls of the dead walked. Great stretches of forest understory were carpeted by the leaves of deerheart, which sent up its small white spires of flowers, and the nearly-luminous, wide, white flowers of bunchberry (one of my companions is alleged to have said that they lighted the way to the outhouse in the darker hours!).

Indian paintbrush provided the most stunning floral array. Here in Juneau we see some yellow-flowered ones and (especially at higher elevations, I think) a few red-flowered ones. But in Bartlett Cove we found a beach meadow simply covered with paintbrush flowers: yellow, red, orange, particolored, and every combination in between. Quite splendid.

Here and there in summer

alpine sights, body-checked by a grouse, some thoughts on bear viewing, and wildlife on the home front

–In early August I went up Gold Ridge in hopes of finding the big, blue, broad-petalled gentian in bloom. Being a rather impatient sort, I’d tried earlier, in July, with no luck. But on this warm, sunny day, there were a few in bloom and more with buds. Higher up on the trail, I didn’t spot any, and they probably bloom slightly later up there. However, the mission was successful on this day, and a search later in the month should find lots more.

broad-petaled-gentian-by-bob-1
Photo by Bob Armstrong

Even if there had been none of those beautiful gentians, the day was a good one. A mountain goat was silhouetted on the ridgeline; young marmots gamboled about, while a big adult lazed on a boulder. There were several bear scats along the trail and, of course, I could not resist inspecting at least the most recent one. It was full of salmonberry seeds, along with some vegetation fibers; because the salmonberries at this elevation were not yet ripe, I knew that this bear had been foraging down lower.

Bird life was not well-represented, however: a pair of curious ravens, a robin, and an invisible sparrow pip-pipping in the alder brush. It is always a little sad when the season of bird song is over for the year. Nary a grouse or ptarmigan to be seen, and I’d seen only one brood in July. Although apparently no official census has been conducted, they seem to be much scarcer on the ridge these days than they were a few years ago. Back in 2005, the area was opened to hunting, and it is very likely that hunting has reduced the grouse and ptarmigan populations. Many of those birds were habituated to people on the trails, and many of us thoroughly enjoyed seeing them and their chicks almost any time we ventured up the ridge. Shooting them would have been easy (and very unsporting). It seems that, for the sake of a few hunters, the pleasure of many observers was reduced.

–When the sockeye come in to Steep Creek, the bears can feast. This summer, the one we know as Nicky came down late, as usual, and she does not have cubs; she’s around eighteen years old and may be slowing down a little. The cubs of Bear 153 put on a good show one evening: swinging on the willows, tussling in the grass, getting startled by a big salmon thrashing upstream, tipping over the camera gear set (by permission) in the stream, cavorting in the shallows. I had dropped by, intending to stay just a few minutes, and ended up staying almost two hours.

The few times I have gone out there to bear-watch, the crowds have been quite well-behaved, not needing much guidance from the rangers about proper conduct in bear country. But with so many people visiting the area, someone (or someone’s dog) inevitably makes a wrong move that makes the mother bears nervous and concerned about their cubs’ safety. This is a time to be especially observant of bear body-language and to give the bears even more space than usual. These bears are quite used to people and normally behave extremely well; we can keep them that way, for all of us to enjoy, if we ourselves behave properly. A new guide to staying safe around bears, including some new information, is in the works; it will be available from ADFG.

–When we were in Bartlett Cove, Glacier Bay, one day in June, we stumbled upon a female grouse that clearly had chicks somewhere nearby. Standing on big rock, she clucked and fussed, even when we stood back to see what might emerge from the tall, dense beach grasses. I circled slowly back around her rock, hoping to see the chicks as they crossed a narrow path. Well! Mama did not like that one bit, and as I inched forward, she gave a body slam to my shoulder as she flew ahead, sounding the alarm. As far as that female was concerned, I had invaded her space and she was not going to stand for it! Then we saw the eight or so chicks—they had already crossed the path and were not close to the mother’s rock at all. Nice big chicks! They all took flight away from the presumed danger (us), followed by mama.

The next day, we managed to upset a pair of greater yellowlegs as we walked out into some extensive beach meadows. Both adults yelled and swooped at us, so we knew that there were chicks in the area. We never did see those chicks, well hidden in the tall grass, and the tumult subsided as soon as we moved out onto the open beach.

–My home pond was a happening place this summer. Four different broods of mallards made it a regular stop on their rounds through the neighborhood. First, there was a brood of ten ducklings (known as the Tens), then a brood of five (the Big Fives), a brood of eight (the Eights), and a later brood of five (the Little Fives). Seldom was there more than one brood on the pond at a time; if two broods happened to be there, one dominated the area under the hanging seed feeder. There was a nice rain of seeds falling from that feeder, as the juncos scratched among the loose seeds and the jays tipped the whole feeder off balance. This was manna from heaven! And not to be shared. The Eights would advance upon the Little Fives, pushing them into a corner of the pond, and go back to gobble up falling seeds. On another day, the roles would be reversed, the Little Fives winning the prize. The Big Fives sometimes charged at The Eights, relegating them to the far upper end of the pond, and went back to snarf up the seed rain.

Several broods of juncos (and their parents) grew fat on the seed offerings, and I watched the young ones gradually acquire their adult plumage. Bears wandered through but did not bother with the inaccessible feeder. I watched two predators with evil intentions about ‘my’ ducks, but they departed, still hungry. A roaming dog threatened one brood, and the mother duck led that dog a merry chase in her version of a broken-wing act: back and forth went dog and duck, the duck always just two or three feet ahead of the dog. She could have just flown away, but she was intent upon keeping that dog away from her young ones. The dog did not respond to orders from the shore, so eventually, my quick-thinking neighbor jumped in and grabbed the dog, and peace was restored.

Live-bearing plants

there are alternatives to producing seeds

On one of many dribbly days in July, as I wandered along a beach on North Douglas, I noticed a little plant with white flowers. It’s called alpine bistort, but at our latitude it also lives in meadows and roadsides at lower elevations. The top of the flowering spike bore small flowers but on the lower part of the spike, where flowers normally develop, there were–not seed capsules or fruits–but small plants.

alpine-bistort-by-bob-armstrong.jpg
Photo by Bob Armstrong

This is an unusual plant because it does not usually produce seeds. Instead, each flower makes a bulb-like structure, and from this grows a tiny little plant. Eventually, the new plantlet falls off and lands on the ground, ready to grow.

Botanists call this habit ‘vivipary’, which means live-bearing or bringing forth live young. The scientific name of the plant (Polygonum viviparum) reflects this habit. The little green plantlet has already started to make its own carbohydrates, so in a sense, it is off to a running start when it lands in a suitable spot nearby. In contrast, a seed might wait until next year, or next decade, before it germinates and produces a seedling.

Calling this habit ‘live-bearing’ does not imply that any seeds produced in the more customary way are dead! Seeds are not dead at all. However, being encased in several layers of tissue gives seeds several options not open to these viviparous plantlets. Seeds can go dormant, in some cases for tens or hundreds of years, awaiting the right conditions for germination. The coverings of a seed may be modified in many ways (wings, sticky coatings, prickly surfaces, edible fruits) that give seeds a variety of ways to be transported to new sites, often at some distance from the parent plant. Thus, seeds can often disperse in time (dormancy) and space, but terrestrial viviparous plantlets often cannot. Moreover, seeds of most plants (but not orchids) contain stored carbohydrates packed into the seed by the mother plant, so they can draw on this stored energy when they germinate and start to grow. Viviparous plantlets do it for themselves.

There aren’t many native viviparous plants in our area. In addition to alpine bistort, we have a couple of grasses that are at least sometimes viviparous and the uncommon snow saxifrage. These species (and some others that live elsewhere) form their plantlets asexually—without pollination and fertilization, so each little plant is like its mother. Asexual vivipary is thought to occur most frequently where suitable terrestrial habitats are very patchy or where favorable seasons for germination and early growth are short.

So these plants have been reported mostly from arctic, alpine, or very arid areas.

Elsewhere in the world, however, some viviparous species produce plantlets by sexual reproduction. The flowers are pollinated and seeds develop, but the embryos begin to grow and, in some cases, plantlets sprout while the seed is still on the mother plant. In these species, there is regular genetic mixing across generations and offspring are not virtually identical to their parents. Many of these species live in warm tropical waters. Perhaps the most famous examples are some mangroves, whose fertilized seeds germinate while still on the parent; the whole young plant then drops off and floats to a new site.

Vivipary has evolved many times in the plant kingdom. Although the conditions that might favor the evolution of vivipary have been discussed by botanists, perhaps the only fairly clear conclusion is that different conditions are probably relevant for different species. As so often happens, there emerges no single, simple explanation.

Marmots

from skyline to shoreline in Southeast Alaska

Marmots belong to the large group of squirrel-like rodents that occur around the world (except Australia and Antarctica). There are over a dozen species of marmot, all in the northern hemisphere, and Alaska has three of them. The woodchuck is found only in the central Interior of Alaska, the westernmost extension of its wide North American range. The Brooks Range (and northwestern Alaska) has its own marmot species, known as Brower’s marmot, which occurs nowhere else in the world. The third species is the hoary marmot (closely related to Brower’s); it lives across southern Alaska, including Southeast, and on southward through the mountains to Montana and Idaho.

Over much of their range, hoary marmots are residents of rocky alpine areas. Hoary marmots have been studied intensively in Washington, where they are the marmot species found at the highest elevations, above the habitats of other marmots. Here we see them on Gold Ridge and the ridges on Douglas Island, for example. In Juneau and probably elsewhere in Southeast, however, marmots are not limited to alpine areas but can be found at sea level, living just above the high tide line, where they like their favorite rock piles too, but sometimes they create burrows in moraines and sandbanks underneath large trees.

Marmots spend a lot of time in their burrows, so we only see them for a limited part of the year. They hibernate for many months during the winter, going to sleep in fall and staying in their burrows until spring. They retreat to their burrows in hot summer weather too, avoiding hot weather and diving underground to avoid predators. Most hikers are familiar with their whistled alarm call, given in response to perceived threats, be they human or canine or eagle; it’s a signal saying ‘Look out! Be ready to dive for cover!”

Hoary marmots favor habitats such as rocky talus slopes, where they can create burrows that are protected from most predators and from the extremes of weather. They dig several kinds of burrows: some are used as hibernation places, some serve as residences for females with young, some are used as living quarters by juveniles or males, and other, smaller, ones serve as refuges in which to hide from sudden danger. Meadows full of tasty greens are always nearby. Burrowing sites and food availability are two important factors that determine where hoary marmots can live. Suitable habitat is limited and patchily distributed.

Burrows are also very important for winter survival. Deep burrows are sheltered from winter cold, and a thick snow cover also helps marmots survive over the winter while they hibernate. Overwinter survival of pups is also related to nutritional status: those that are born late in spring/summer have a shorter period of time in which to feed, so they enter hibernation with less fat than those born early in the season, and are less likely to survive than pups that fed all summer long.

Hoary marmots mature when they are three years old. Females generally start breeding when they reach maturity, usually bearing offspring in alternate years. Young marmots stay with their mother until they are two years old; then they may disperse to other areas. Females with pups or yearlings have residence burrows that are not shared with other individuals.

Mature males generally hold territories in suitable habitat, sharing that space with females, juveniles, and pups. After maturation, however, some males may spend a year or more as vagrants or as subordinate satellites within an established territory of a dominant male. Satellites may move up to become a territory owner when the previous owner dies.

If the territory of a mature male contains rich foraging grounds and good burrow locations for more than one female and her offspring, two (rarely three) females may settle there. Not content to have one or two females, territorial males sometimes go gallivanting to other territories, looking for casual liaisons (note that this implies the existence of willing females!). Gallivanting appears to be relatively rare, however, so presumably most of the offspring born on a territory are fathered by the resident male.

Are bigamy and monogamy equally successful in leaving offspring for the next generations? One would think that bigamous males (with two females) would father more offspring than monogamous males, in general. However, studies in the Pacific Northwest indicate that monogamous males may last longer as territory owners than bigamous males. Furthermore, females mated to a bigamous male are more likely to skip an extra year between litters. So the lifetime legacies (measured in number of descendants) of bigamous and monogamous males may not differ greatly. For females, however, the lower frequency of reproduction in a bigamous relationship probably means that they have a lower lifetime output of young than females in monogamous relationships, on average.

I would love to see a good study of marmots in Southeast. Do marmots in Southeast fit the examples revealed by studies in the Pacific Northwest? Do alpine and beach marmots differ in their social arrangements, such as the frequency of bigamy, and the effects of mating arrangements on survival and production of young? Does survival of pups or adults differ with elevation? The potential length of the summer feeding period is surely greater at low elevation….unless beach marmots have to spend more burrow time in summer, to escape hot weather (if any). Research funds are sadly scarce these days, so such questions may not be answered in the near future.

Spruce bud blight

an unwelcome new threat to Southeast Alaska forests

There’s a new, probably non-native, invasive species in town, just discovered in late June. It’s a disease-causing fungus (Gemmamyces piceae) that afflicts spruce buds, often killing them altogether but sometimes just causing deformed buds and twigs. Heavily infected trees that lose many buds cannot make new needles that allow the tree to continue growing; old needles drop off naturally after a few years of service. Without new needles, eventually these severely damaged trees are likely to die. Although we know that Sitka spruce is susceptible, we do not yet know if it is prone to such severe, lethal infection. In any case, this is not something we would welcome in our multi-valued spruce forests!

Infestations of this pathogenic fungus were first noticed on the Kenai, in 2013, and later discovered near Anchorage and Fairbanks. Recent surveys have found that this fungus is apparently widespread in Southcentral and Interior Alaska, at least is road-accessible locations. Researchers are now beginning to study genetic variation in the population, which will help determine how long it has been in Alaska, as well as assess its native/nonnative status. Now it is in Juneau, on Sitka spruce trees near the Shrine of St Therese. Recognizing the potential seriousness of the now-localized outbreak, and in hopes of preventing its spread, scientists with Forest Health Protection at the Forestry Science Lab and the staff at the Shrine have worked together to remove and burn all spruce trees that show signs and symptoms of this fungal infection—to ‘nip it in the bud’, so to speak. This site and others will be now monitored by those scientists for indications that the infection has spread.

Researchers suspect that the fungus was introduced to Alaska by arriving on previously infected ornamental spruces that were brought in and planted. The movement of live plant material is a key pathway for the introduction of plant diseases. Colorado blue spruce, for example, is highly susceptible to this pathogenic fungus and is commonly planted as an ornamental in parks and gardens. In Europe, Colorado blue spruce has been widely used in plantations, to ‘replace’ logged-off natural forests, and in the Czech Republic the fungus has killed trees on many thousands of acres of those plantations of introduced spruces. Although the fungus was present in central Europe for some time previously, relatively recent environmental conditions of temperature and humidity probably made possible the destructive outbreak of the disease; the fungus does well in cool conditions.

Spores of this fungus disperse to new sites on the wind. But they also can be carried by rain, from infected upper branches to lower ones on the same tree. The existing fungal infections at the Shrine may already have sent spores to new sites, or it may do so in the coming weeks, if undetected infections remain. The spores infect next year’s buds, which are very small now (July); next year, these buds may be black and dead, or still alive but bent and deformed.

spruce-bud-blight-spore-producing-Loretta-Winton-USFS
Infected buds. Photo by Loretta Winston

What are the signs of infection by this fungus? When the fungus is mature, it develops a black, lumpy, spore-producing body on buds and new growth. One can see symptoms of previous infection on twigs that are two or three years old: they are bent at an angle, very unlike the natural growth pattern.

spruce-bud-blight-bent-twig-Loretta-Winton-USFS
Characteristic bent twig. Photo by Loretta Winston

Forest Health professionals at the Juneau Forestry Sciences Laboratory (U. S. Forest Service) are asking Juneau folks to be on the lookout for signs and symptoms of infection on our Sitka spruces. If you see them, please report them to Forest Pathologist Robin Mulvey (586-7971, 500-4962; rlmulvey@fs.fed.us). Send a close-up photo to her email if you can, along with precise location information. If you collect the infected twigs for a specimen, be sure to put them in a well-closed plastic bag so no spores can escape!

Good finds in Gustavus

stealthy spiders, ambitious amphibians, strange ferns, and more

A summertime walk through woods and meadows is almost always good—birds are singing, flowers are blooming, and there’s always nice fresh air. But sometimes all the little pleasures form a base on which rest some observations of particular interest. Here are a few good ones from a recent trip to Gustavus.

–Dandelions had mostly gone to seed, so fields that had been golden with flowers were now white with plumes on mature seeds ready to disperse on the wind. But here and there we found a laggard flower, still yellow and conspicuous on the background of white. On one of these late bloomers there was a bumblebee, a strangely immobile bee. Looking more closely, we saw a yellow crab spider with the bee in its clutches. Crab spiders are venomous (to insects), immobilizing their prey and then sucking out the juices. Dinner was in progress and the bee would fly no more. Crab spiders are generally ambush-predators; some of them lurk on flowers in hopes that a tasty insect will alight. The color of the spider often matches the color of the flower on which it awaits a victim.

crab-spider-howard
photo by Kerry Howard

–The ponds at the gravel pits are a great place to see shorebirds, swallows, and kingfishers. There were sticklebacks swimming around and, in June, there were gravid females full of eggs. One pond held many thousands of toad tadpoles, swarming in the shallows where the water temperature was salubrious. They came in a variety of sizes—some at least six times bigger than the smallest. A female toad can lay thousands of eggs; the hordes of tadpoles that we saw undoubtedly had many mothers, which probably laid their eggs at somewhat different times, accounting for the size variation. None of them had begun to transform into toadlets; no little legs were visible. A dense pack of tadpoles clustered around a silvery object, each one trying to grab a mouthful. Looking closely, we discovered that the silvery object was a dead stickleback. Toad tadpoles commonly feed on algae and detritus, but they are also known to scavenge carrion and even the dead bodies of their comrades. Toad (and frog) populations have declined dramatically almost everywhere, and it was heartening to see this large aggregation of juveniles.

–Gustavus is noted for (among other things) its wide sandy beaches. On our way out to one of them, we heard some odd sounds, rather like the hooting of a small owl. As we listened carefully, however, it became apparent that several snipes were performing their aerial territorial display. It’s called ‘winnowing’, and it’s made by the rapid passage of air over the spread-out tail feathers, usually as the bird dives toward the ground from high in the air. Usually the male does this but sometimes females do too. I hadn’t heard this display for a long time and it was a gladsome sound.

–Out on the sandy beaches we found windrows of long, flexible tubes that were the former housing of certain marine worms. The worms were long gone, possibly starved at the end of winter when food is scarce. Then the tides presumably stripped the empty tubes from their attachment points and piled them up on the beach. This observation stimulated a lot of conjecture but no concrete answers.

–On the vegetated sand dunes there were lots of the strange little ferns called moonworts (a.k.a. grape ferns). They don’t look at all like ferns to the layman’s eyes, because the fronds are generally not very lacy or branched. We found many that appeared to be the common moonwort, but there were also a few much more robust individuals that were certainly a different species. On one of the postglacial-uplift meadows we found another kind, one that is now classified in a different genus; the fronds on this one (so-called rattlesnake fern) are somewhat more ‘fern-y’. All three of these are widespread species in North America and even beyond, but they are so odd that it is always fun to find them.

–The pilings of the public dock usually offer something even to a casual observer. Enormous white anemones, far larger than any we usually see in the rocky intertidal zone, wave their tentacles if the tide is in. Sea stars cling to the vertical surfaces too, but the largest ones have trouble hanging on when the tide goes out and leaves them above the waterline. Colorful sponges and tunicates add to the array. Sometimes there’s a giant whelk laying a coil of egg cases. Small fish sometimes gather under the docks and are visible between the pilings. And while one inspects the fauna on the dock, barn swallows are swooping overhead, gathering flies and mosquitoes for their chicks.

–We searched for lady’s slipper orchids (of which more, later). One clump of flowering stems still included a stalk with last year’s seed capsule, well dried. Someone opened the capsule to see if any seeds were left and found, instead, a tiny spider guarding her minute ball of orange eggs. We were sorry to have destroyed her safe-house!

–Sweetgrass grows in many Gustavian meadows and some of us stopped to braid some stems. Braided sweetgrass is used, especially by Native Americans, to construct baskets and decorative items, and we had to try just a simple braid. As we concentrated on our task, we heard thundering hoofbeats, getting rapidly closer. Turning around, we saw a fast-trotting female moose, followed by a young calf. 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.