Category Archives: Nature

Articles on nature and the natural history of the Grand Traverse Region. From descriptions of geological strata or animals and plants of the Great Lakes states to nature walks and gardens of the region, this feature covers everything in the great outdoors.

The Earliest Butterfly of Spring: The Mourning Cloak

Mourning Cloak Butterfly, image courtesy Andy Reago and Chrissy McClarren, https://www.flickr.com/photos/wildreturn/.
Mourning Cloak Butterfly, image courtesy Andy Reago and Chrissy McClarren, https://www.flickr.com/photos/wildreturn/.

It is a sunny day in March, the temperature hitting close to sixty degrees and I am out hunting for Mourning Cloak butterflies.  The drifts of snow still covering the north slopes and hollows do not discourage me because I know their habits: they emerge early in spring–earlier than any other butterfly–seeking sweetness in damaged trees leaking sap as well as mates to continue their life cycle.  Up ahead among the hardwood trunks of beech and maple I see a dark flutter—Mourning Cloaks, two of them flying in a tight spiral, a mating dance.  I raise my hands to the sky for a moment as an expression of joy at my discovery.  As I do, another Mourning Cloak I had missed in my concentration upon the first pair draws close and boldly lands upon the sleeve of my jacket.  It flexes his wings once or twice and I beam with joy: What an intelligent and friendly animal this is!  We bask in each other’s company.

Mourning Cloaks overwinter as adults, crawling into warm spaces underneath bark or stones, close to soil that remains unfrozen all year long.  Among the earliest wildflowers, the Spring Beauties and the Hepatica, they dance in the sunlight, ready to mate, lay eggs, and die, thereby completing their life cycle within a calendar year.  The eggs, laid upon host plants poplar and willow, hatch into dark spiky caterpillars, creatures one would hardly guess would change into a splendid adult butterfly.

The adult is mostly a uniform purple-black, a muted yellow border on its wings with a row of blue dots inside of that.  Having lived a year already, its wings might appear battered and faded, not furnished with the glowing colors it showed upon its emergence from its pupal case.

This butterfly, like many others, is territorial, males often proclaiming their rights by lighting on the highest object around, understory trees, for example, or hands outstretched in joy at having found Mourning Cloaks in the first days of spring.  Or, then again, with that behavior they might be proving they are especially intelligent and friendly insects!

I have found Mourning Cloaks in Northern Michigan hardwoods–consisting of beech, sugar maple, white ash, black cherry–in the months of March, April, and May.  They disappear for much of the summer as eggs hatch into caterpillars, caterpillars transform into butterflies, and butterflies “sleep” during the hottest summer months, aestivation the term given to this period of dormancy.  In late summer and early fall they appear again, the new adults, seeking nectar and food to get them through our long, cold winters.

Sharp-lobed Hepatica, one of the earliest spring flowers, adored by Mourning Cloak's and people alike. Image courtesy of Jason Sturner, https://www.flickr.com/photos/50352333@N06/.
Sharp-lobed Hepatica, one of the earliest spring flowers, adored by Mourning Cloak’s and people alike. Image courtesy of Jason Sturner, https://www.flickr.com/photos/50352333@N06/.

The Mourning Cloak is the animal equivalent of Spring Beauty, Trailing Arbutus, and Hepatica, the first wildflowers to appear in spring.  We welcome it as we do those flowers, the earliest sign that warmth is returning to the world.  Whether you visit the woods for morels or for wildflowers, keep an eye out for these butterflies.  And if you hold your hands up, you just might get one to land on you.

Richard Fidler is co-editor of Grand Traverse Journal.

The Microscopic World of Springtails and Snowfleas

“I love to watch the jumpers when I water my houseplants,” she said.

“What jumpers?”  I asked.

“Whenever I water them, you can see little bugs jump up.  Want to see them?” She went to get her watering can.   As she soaked the largest plant, a Norfolk Island Pine, I could see nearly microscopic beings jumping several inches from the soil.

“Do you see them?” she asked.  “Aren’t they cute?”

“I do see them—and, yes, they are cute.  And I think I know what they are.”

Some years ago, when I first began to study ecology, the class set up a Berlese funnel, a device designed to capture animals in the leaf litter, the topmost layer of the forest floor.  It consisted of a large metallic funnel into which a sample of leaves, sticks, and soil had been placed.  Above was an incandescent bulb, low wattage, which provided the heat required to bake the critters out.  As the sample dried, they would migrate to the narrow part of the funnel, eventually falling into a jar of alcohol.  The menagerie of tiny animals was too diverse to describe in detail here, but one inhabitant was both abundant and memorable: springtails.

Springtails are only a millimeter or so long, only visible to our eyes if we are paying careful attention.  They have six legs and an odd lever at the end of their abdomens that springs forward, propelling them up in the air.  In the past they were regarded as insects, but now, in the day of DNA analysis, they have been removed from that taxon.  They are now classified in their own taxonomic group Entognatha, that name pointing to the animal’s internal mouthparts.

Mostly springtails live on dead and decaying plant matter.  They are partly responsible for converting the dead leaves of autumn into black humus.  It takes hordes of them to accomplish that work: one estimate of their abundance suggests there might be at least 100,000 of them per square meter.

In winter, not all species of springtails are dormant.  On warm days some of them—snowfleas as they are commonly called–can be seen hopping on the granular snow, sometimes discoloring it with their tiny bodies which measure less than a millimeter in many cases.  They have small lever affairs on their abdomens that are under tension when locked in position.  When aroused, they unlock the mechanism and spring upwards, sometimes 50 or 100 times their body length.  One wonders how much fun that must be!

In the waning days of winter, look carefully at the snow at the base of trees.  Can you see them hop when you move your hand close?  I will include a link to an encounter with snowfleas.  You can watch it without the sting of cold, though it would be better if you got out there to see the real thing!  https://www.youtube.com/watch?v=VjLKzogOj8Q

Richard Fidler is co-author of Grand Traverse Journal.

Investigating the Gull’s World: Bellows Island of Leelanau County

by William C. Scharf

It’s early on a clear, sunny morning in mid-April. Lake Michigan is calm and the water looks smooth as glass. Hold on a second, it is glass! That’s a common result in this season, when waves are absent and temperature drops to freezing overnight. The outboard motor starts cutting through the nearly inch-thick skim ice. I throttle back because I’m frightened. There seems a real possibility that a planing boat could lift itself right on over the surface of the thin ice. That could spell some sort of disaster!

An imagined news report says, “16 foot aluminum puck with airborne, roaring outboard motor, skimming along ice, hits weak spot, then noses in on impact and slips under ice. Body found trapped beneath ice.”

Better to slow down. The sound of ice cracking is like breaking plate glass windows, and I begin to wonder, could really sharp ice sheets puncture an aluminum boat? Directly behind the boat are room-sized, jagged, transparent sheets sticking out of the water at various angles, and as I look further back there is a black path that I have cut in the ice. It’s very easy to see where I opened-up the motor (straight black line) and, where I got worried (the many course corrections cause zig-zags).

Why am I doing this? It’s nesting season for herring gulls.  I’m heading for Bellows Island, sometimes called Gull Island. There, I have permission of the island’s owners, the Leelanau Conservancy, to continue my long-term studies begun as student field trips over thirty years ago.  We started by studying the non-verbal communications systems of herring gulls worked out by Nobel Laureate, Niko Tinbergen.

Generations of my students will recall the video of Tinbergen with his thick Dutch accent proclaiming, as he strikes an offensive clenched fist pose, “When I do this, you know exactly what I mean.” He did that to show that certain signals have universal meaning.  His interpretations of gull sign language are still widely accepted as definitive basic communication among vertebrates, and his conclusions also have many applications to human behaviors. For example, smiling to express a friendly attitude is universally accepted among humans.  Or, a crying baby reveals discomfort and elicits motherly behavior. We instinctively understand these signals, and so too, the gulls have also evolved their own precise set of instinctive signals.

The sole inhabitants of Bellows Island, also known as Gull Island, busily nesting.
The sole inhabitants of Bellows Island, also known as Gull Island, busily nesting.

Gulls are highly territorial, meaning that they defend a small area, around their nests. Gulls have special threat postures that signal to possible intruders, but define the territorial boundaries to their mate.  It is with aggressive behavioral encounters between strangers that gulls communicate each pair’s boundaries to the rest of the colony. Ironically, it is acts of aggression that make a cooperative and happy colony. That is, as long as territories are recognized and respected, there is peace, order and calm in the colony. Through threatened and occasionally overt aggression, to twist the poet’s phrase, “good neighbors make good fences”, even if the fences are invisible and symbolic as in the case of the gulls.

The processes of pair formation and courtship has its own signals of love and pairing.  The formation of the pair, or the engagement party, is usually celebrated when the male regurgitates his last meal to share with his mate. She must be well fed to ensure viable eggs, and the gesture of sharing his meal signals the pair bonding together symbolically. Occasionally, a male that has just decided to “get engaged” changes his mind and re-ingests the food himself, thus, calling off the engagement. It may be nothing more than the fact that he is hungry, but it represses the pair bond until such time as he can share fully.

Chick rearing also has its own unique signals. The chicks learn to beg for food by pecking at a special orange spot on the adult’s bill. A pecking signal from the chick at the spot on the bill leads the adult to bring up food for the chick. Tinbergen called such specialized signals “sign stimuli.” Parents also communicate their territorial boundaries to their chicks.  If a chick strays into another territory, that chick is in danger of being attacked by the adult pair in that territory. Such attacks lead to severe injury or death to the stray chick. Strays that are killed are often eaten by the neighboring territorial adults.

The state of organization and benefits of nesting in a colony have prompted some to describe a colony as “Gull City.”  Indeed a colony benefits from social communication beyond the benefits necessary for individuals to function. Signals recognized by the masses are complete with penalties for transgressors and rewards for obedient citizens. Gulls communicate the location of food sources by watching the success of others. They synchronize their nesting cycles through day length and social behavior, which leads to laying eggs on about the same day. The degree of synchrony in egg-laying is a good measure of the social stability and behavioral cohesiveness of “Gull City.”  Large numbers of gulls nest together to overwhelm potential predators. Gulls choose isolated island sites for their colonies because such islands lack ground based predators such as foxes, raccoons, skunks and weasels. Occasionally, colonies nearer the mainland are visited by owls or hawks that can kill large numbers of both adults and chicks or a fox may gain access to an island over winter ice. Initially a fox in a gull colony may find a rich food supply of adults, eggs or chicks, but when the gulls are done nesting in late June or July, the fox had better learn to swim quickly, if  it wants to continue eating.

My students and I were curious about other aspects of the gulls’ lives, such as: When they leave the colony where do they go? Are the sex ratios even? Do they return to their hatching colony?  What ages are the nesting gulls?  As we began to answer these questions still others popped up. It was only a short time until we were putting numbered, aluminum bands on gull chicks to find the answers to these and other questions. We had to know the “who” about the gulls before we could answer questions about “how” and “why.” Banding was the best way to do this. We used U.S. Geological Survey Bands that weigh less than one-tenth of a percent of the bird’s body-weight.  That seems similar to humans wearing jewelry.  Dangers to chicks from other adult gulls, while we were banding, were monitored carefully, and all humane protocols were subscribed to.  All of this was done under Federal and Michigan permits issued to me. I had been trained during a summer internship with Frances Hamerstrom in Wisconsin and two summers with Edward Balfour in Scotland. I have since qualified as a trainer of new banders, and been approved by veterinary animal care and use committees at two research institutions.

Bellows Island, southern-most herring gull colony in this part of Lake Michigan, is a bastion against the onslaught of increasing numbers of smaller gulls, the ring-billed gulls.  Ring-bills are the nuisance birds begging and eating garbage around fast-food outlets and parks. The ring-bills often out-compete the larger herring gulls at other nesting sites, because of their social structure, close nesting habit, and increased ability to thrive on a generalists diet augmented by human refuse and agriculture. Herring gulls are more specialized and less generalists in their food habits, and thrive primarily from dead fish or water-related scavenging. In recent years, parts of Bellows Island have been usurped over by another fish-eating bird, the Double-crested Cormorant.  I will leave cormorant discussions for another time.

Herring gulls from Bellows Island travel long distances in winter, mostly in their first three years. Later, as adults, they winter closer to home.  Many bands of young birds have been returned from throughout the Great Lakes region. That is: New York to Northern Wisconsin, and south to Ohio and Illinois. A few seem to wander north into Ontario and Quebec. Often the location of a leg band, found during the nesting season, is the site of another nesting colony. Many more of our bands have turned up at distant nesting sites than the reverse. That seems to point to Bellows Island serving as a “source” of new reproductive gulls rather than as a “sink” by donating excess reproduction from Bellows Island to other localities with space for newly recruited breeders.

Dozens of bands have been returned from southern states and the Gulf of Mexico in the winter.  A noteworthy Bellows Island band return came from the mouth of the Plano River in the Central American country, Honduras. The report came attached with an interesting story communicated by Dr. Miklos Udvardy, of California State University at Sacramento, who, while on a research expedition, had bartered the band from a native. According to Udvardy, the native was wearing the band as personal jewelry, and when asked what kind of bird it came from, the native answered that he didn’t know, but the bird tasted very good.

I don’t begrudge the native his taste for wild game. Rather, I have greater concern for his health, because of the toxic contamination borne by Great Lakes herring gulls. Even though the level of toxic contamination in gulls has been declining in recent years, some of it is still present. At one point in the 1960s, Dr. James Ludwig, then of the University of Michigan, found that Bellows Island was among the highest in contamination for herring gull eggs that he tested. At that time, the hatchability of the eggs from Bellows Island was very low. Ludwig is convinced, and has written and spoke extensively, that there was a linkage between toxics and infertility in the gulls. Drs. Gary Shugart and Mary Fitch, in the mid 1980s, found a distinct shortage of male gulls on Bellows Island.  They think that this unbalanced sex ratio is what caused large numbers of females to nest with other females. Of course, such pairings usually produced infertile eggs, unless one of the females had previously mated with a male. This same shortage of males caused other females to make nests side-by-side in a single male gull’s territory. This trio usually produced chicks from only one of the sets of eggs with the second female becoming a helper in raising chicks from the successful nest. Un-balanced sex ratios may also be linked to toxic concentrations. We don’t know. But, these chemicals are known to be powerful disrupters of body functions, and reproduction. Some toxics have been shown to have a feminizing action on embryos in the egg. While it is distinctly unlawful to kill a gull with a gun, mass killing through reproductive disruption most often goes unpunished because its perpetrators are too difficult to track down with certainty.

For the past few years, I have been taking advantage of our past banding work by studying the large number of banded gulls returning as adults to nest on Bellows Island. I read the bands with strong binoculars early in the nesting cycle, before chicks are hatched to minimize my disturbance in the colony. Or, when I locate a banded bird, I use a simple, safe trapping technique. I release the bird quickly, after a short time for weighing, measuring and reading its band. So far, all but one of the approximately seventy five bands read from adults at Bellows Island, have been hatched there. The one foreigner came from a hatching colony near Alpena. So, we know now that our gulls come home to nest.

But there is much more that the bands can tell. Previously banded, nesting herring gulls on Bellows Island average seven-and-one- half years of age. They never start nesting before four years of age, and we have recorded eight nesters between ten and fifteen years, three between fifteen and twenty, and two over twenty with the oldest being twenty-four. The bands wear off as the gulls age.  Band-loss due to abrasion and chemical weathering is the greatest source of error in our studies. It is highly probable that many of the gulls nesting on Bellows Island are well over twenty years old, but have lost the leg-band that would prove it. The band on the twenty-four-year-old was paper thin, and ready to drop off.

This gull politely sits, allowing us a good view of its eye color. The author is able to tell the age of gulls from afar, as their eye color changes as they age.
This gull politely sits, allowing us a good view of its eye color. The author is able to tell the age of gulls from afar, as their eye color changes as they age.

Another obvious change with age in herring gulls is the gradual lightening of their eye color. The chicks start out with a dark brown eye, the eye becomes grayish sometime in its first winter, but by the time of first breeding it has become a bright yellow. The yellow fades, and becomes pale and almost white with flecks in later years. We can also separate males from females visually because males are larger, have different mating behaviors than females, and seem to be leaders in territorial defenses.

What good is it to know this? It helps immensely to be able to age and sex the birds without bands. Just by looking in their eye from a distance, or telling their sex by their size and behavior could help our studies a great deal.  As anyone studying populations of animals or humans will explain, age and sex are the two most important factors to understanding dynamics of species groups.

Going to Bellows Island is not for everybody.  In fact the Leelanau Conservancy, owners of the island, prohibits access without their permission.  The ruins of the old house there are extremely unsafe. The chicks can receive severe damage, and even be killed by neighboring adults when they are frightened out of their parents’ territories. Such an occurrence damages the colony’s reproduction and stability, lasting on into subsequent years.  This is often the innocent result of uninformed and unknowing visitors.  A camera club from a neighboring state frequently held an annual outing there in past years. The timing was usually correct to catch the chicks at their most photogenic stage. Despite my warnings, they always left a carnage of dead chicks, due to their disrespect for the gull territories.  Occasionally, dead chicks found after the camera club visit, or after a severe June storm, were ones that we had banded earlier. Other people finding banded, dead chicks naturally blamed us, quite unfairly.  Thankfully, the photographers seem to have ended their half-day excursions. In 1996, I wrote a management plan for the Leelanau Conservancy detailing cautionary procedures for people accessing Bellow Island, assuming they had obtained the Conservancy’s permission.

Author's student was injured after a gull swooped down on him. Hard hats are now "de rigueur" for the author's visits.
Author’s student Scott Thomasma was injured after a gull swooped down on him. Hard hats are now “de rigueur” for the author’s visits.

I always wear a hard-hat for protection when entering the gull colony. One of my students once received a nasty gash in his head from being raked by the beak of a gull swooping down on him at forty miles-per-hour. Additionally, there are certain bird-to-soil respiratory pathogens which are known to inhabit the soils of similar sites. The putrefying whitewash, occasional dead gulls, standing puddles of well-fertilized, stagnant water and regurgitated fish from thousands of gull chicks make a fertile breeding ground for several kinds of bacteria and fungi. I, my children and several generations of students probably test positive for such organisms without having clinical symptoms.  This may be no worse than we might have sustained by entering a chicken coop, or a church, or other old building with a pigeon roost in its attic. But, be forewarned.

The danger of infection is only for a few weeks in late spring or early summer when the spores are airborne, and then only if you are right in the gull nesting area. The danger of infection is practically zero for someone watching from the distance of a boat, which I recommend.  Each year since the Leelanau Conservancy purchased the island, Kathy Firestone and I have led a trip to observe the nesting gulls and discuss the history of the island from the Inland Seas schoolship. The cacophony, and unpleasantness of aerial fecal material experienced while actually in the gull colony can be turned into enjoyment from the distance of the ship’s deck with refreshments in hand. We would welcome your participation.

For me, it is many early mornings of hooking up a boat and trailer, the vagaries of weather on the lake, the endurance of tons of whitewash from above, and the deafening cry of hundreds of flying gulls. It is wonderful. Yes, you’ve got to love this work, because its rewards only come years later in the analysis of data and finding out what makes this “Gull City” tick. My banded birds are still coming back year-after-year, and I want to be there to document the intricacies of their lives. To the many students and friends, who made this study possible, I owe much. Perhaps, continuing it is a tribute to them. This research is on-going and will continue.

Bill Scharf is Professor Emeritus at Northwestern Michigan College where he led students on scientific study trips on Lake Michigan islands for 27 years. He holds an undergraduate degree from the University of Wisconsin Stevens Point, and Masters and Ph.D. from the University of Minnesota. He has studied harriers in Wisconsin and Orkney, Scotland, colonial nesting seabirds and migrating songbirds on the Great Lakes, and for 4 years after his NMC retirement, was Associate Director of the Biological Station at the University of Nebraska. While in Nebraska he wrote the Birds of North America account of the Orchard Oriole as well as studies on islands in the Platte River. He returned to Michigan to direct the Whitefish Point Bird Observatory, and currently resides in Traverse City.

For the Love of Spiders

In winter the animal world goes to sleep—or, at least becomes less apparent to us.  In particular, the world of small living things disappears, the world of insects, millipedes, centipedes—and spiders. 

The absence of spiders is particularly distressing.  They decorate my dwelling place inside and out during summer and fall.  In my youth I have been known to keep them as erstwhile pets, feeding them a disabled fly, perhaps, or some other insect.  Once, when I was in early adolescence, I kept a funnel-web weaver in my room, sustaining it with insect prey well into winter until my mother vacuumed it one day, not understanding my attachment to the animal.  The haiku poet Issa says,

Don’t worry, spiders,
I keep house
casually.

We are of like mind.

I am hardly an expert in spiders: I encounter them separately as each enters my consciousness—by chance, not searching them out.  Some, like the funnel-web weaver can be identified by the shape of its web, a sheet of silk that tapers to a narrow opening where its inhabitant lives.  The orb weaver makes a gorgeous web with spokes and concentric circles.  I love the name of one of them, Argiope aurantia, a name that comes from one of the Greek naiads or water spirits.  She—and the inhabitants of webs are female—weaves a gorgeous structure out of the finest silk to capture whatever small thing blunders its way into the sticky strands, a story both horrifying and fascinating.  I confess as a child tearing of a leg of a grasshopper and feeding the twitching body to a yellow-bodied Argiope aurantia, poised in her web to bite and wrap up her prey.  Far from signaling the beginnings of major psychosis, it was just a small child’s introduction to life-and-death, an encounter that stays with me still.

Wolf spiders terrify us with their size—with legs extended they barely fit in a teacup—their furry bodies, and their speed as they flee from us or go after prey.  Similar to them are fishing spiders, one of which, the Dark Fishing Spider is the largest spider in North America, its body more than an inch long.  It journeys far from water, often winding up in cabins and homes near the water.  It feeds upon full grown crickets and small children (just joking). A naturalist friend of mine recently emailed me an image of one she caught in her home close to West Grand Traverse Bay.  With compassion, she merely let it go outside her home rather than crushing it with her heel. 

Then there are the jumping spiders, nervous creatures with two great eyes in the front of its head, looking more like us that all the others.  They build no webs at all, preferring to wander about in search of prey, dragging a silk thread behind them.  With so much to say about them, they deserve a separate article in the Grand Traverse Journal.

Cellar spider with prey. Image courtesy of Tom Blackwell through a Creative Commons license on Flickr.
Cellar spider with prey. Image courtesy of Tom Blackwell through a Creative Commons license on Flickr.

Finally, there are the cellar spiders, the most common ones we see around the house.  With long legs and narrow bodies, they are sometimes erroneously called “daddy long legs spiders”, a term that signifies the harvestmen, not a spider at all.  They hang upside down in its poorly crafted web, a “cobweb” waiting for prey.  My favorite spider book, Spiders of the North Woods, tells me that when disturbed, they may shake their bodies, making them appear as a blur.  I will have to test that out.

Are spiders dangerous?  Not for the most part.  The Black Widow does have a poisonous bite and I have seen them around here.  A bite would sicken the victim but not kill him/her.  Other spiders hurt if they bite, but most of them cannot even penetrate the skin.  Many wounds attributed to spiders were caused by other vermin, fleas, ticks, or insects. 

We need to show them respect, especially in the winter when we see few wild living things close to the house.  Maybe we can let the cellar spiders live out the cold months—at least as long as they stay in the cellar.

Richard Fidler is co-editor of Grand Traverse Journal.

Where Wind Polishes and Erodes: Lag Gravels and Ventifact Fields Along the Great Lakes

Some years ago I took a summer geology course from Central Michigan University at its Beaver Island Biological Station.  The professor, an enthusiastic geologist named Richard Dietrich, introduced me to such wonders as vugs, banded gneiss, rhyolite porphyry, and ventifacts.  While much of the knowledge gained about these topics has inexplicably evaporated into thin air, I do recall ventifacts in some detail, perhaps because I have identified several ventifact fields locally.

Students of Latin may know the meaning of “ventifact” from the word itself.  It is derived from the word ventus, wind, from which we get “vent” and “ventilation”. A ventifact is an object, often a stone, which has been shaped by the wind.  A ventifact field, sometimes called a “lag gravel”, is a place where such things are found–often in dry sandy places like a desert or the surface of the planet Mars.

Beach area with all the qualities required to create a ventifact field.

Lag gravels are associated with sandy beaches liberally mixed with stones, but not every such beach is a lag gravel.  The beach must be exposed to long fetch of prevailing winds, not protected by nearby bluffs or foredunes.   It also should be protected from invasions of humans piloting vehicles at the shore or bearing beach paraphernalia: Frisbees, beach balls, volleyball nets, and all other such sources of amusement.  Ventifacts are only found where human traffic is at a minimum.

How is a ventifact field different from an ordinary beach?  The simplest way to tell is by looking at the stones in relation to the sand: Are they embedded or perched?  Perched stones stand up on the surface, the surrounding sand having been blown away.  The stones themselves, upon careful observation with a magnifier, display the characteristics of wind-driven abrasion: a high polish on exposed surfaces of those made of hard minerals like granite and a pitted, eroded surface on those composed of softer rock.

Lag gravel lying undisturbed, at a ventifact field in the Grand Traverse Region.
Lag gravel lying undisturbed, at a ventifact field in the Grand Traverse Region.

Polished stones shine in the sunlight on surfaces exposed to the wind, the surface resting on the ground showing no such luster even if washed and dried.  Fossils stand out in relief as the softer stone around them wore down: Petoskey stones are especially striking, not requiring the usual hand polishing required to bring out their design.  Best of all (for me) are the sedimentary rocks like siltstone or shale which, under ten power magnification, look like miniature scenes from eroded places out west like the Badlands of North Dakota or rocky areas of New Mexico.  Mixed in with the rocks are occasional pieces of weathered glass or slag from old iron smelting operations.  They frequently find a place upon windowsills or within boxes people keep to remember their experiences.  Artifacts like these connect us with those who lived here long ago.

How does the wind polish and erode ventifacts?  At first it was thought that blowing sand did the job, but on closer inspection, it turned out that wind-driven dust (derived from sand) played the most important role.  It takes a mighty wind to lift sand, but less to blow dust.  Stones can be polished even on days of lighter winds.

I won’t tell you exactly where ventifact fields are because I do not want to increase human traffic in these precious places, but I will tell you this: Sleeping Bear National Lakeshore has them.  So does one isolated beach along Grand Traverse Bay.  If you go out looking for one, remember to look for a broad beach with perched stones—and the stones do not have to be large—they can be only pebble-sized.  Be sure to bring your magnifier, at least ten power.  To see the fossils in relief, the shiny surfaces, and eroded landscapes you will need at least that magnification.  If you find a ventifact field, be guarded as to whom you tell.  There are places endangered for their geology as well as for their biology.  We need to protect them, too.

Richard Fidler is co-editor of Grand Traverse Journal. He enjoys a long hike to undisturbed beaches, and leaves them the same way.

Answer to October’s mystery sculpture location

Thanks to Richard Jarvis and Tom Lhamon, online readers of the Journal, we have our answer! This sculpture sits outside the Grand Traverse County Courthouse.

The editors would like to call your attention to a fundraiser to restore the Courthouse clock, a historic landmark for Traverse City residents. The funds raised will go toward restoring the chimes, then the mechanisms and facing: http://www.co.grand-traverse.mi.us/departments/Treasurer/Donation_fund.htm

The Truth About Oak Apples

Oak apples are clearly a fraud.  Everyone knows oaks make acorns, not apples.  Still, the term exists—and if you look carefully in mid- to late summer, you might even find them.  Oaks grow in Northern Michigan, occupying the northern boundary of their range with few individuals being found in the Upper Peninsula.  In Traverse City we can find white oaks—those with rounded leaf lobes—and members of the red oak group—those with pointed lobes.

Compared to real apples, oak apples are puny, only a couple of inches in diameter, lacking both the texture and the crunch of the real thing.  If you open the firm papery shell of one, you may find long, stringy fibers extending from the rind to a central nucleus.   Alternatively, you may find that space filled with spongy matter like packing material.  This wooly stuffing contains tannin, a brown pigment that especially suited for artwork and documents of many kinds.  Here is a recipe typical of that Leonardo da Vinci might have used:

Take an ounce of beaten gaule, three or four ounces of gum arabicke, put them together in a pot of raine water, and when the gum is almost consumed, strain it through a cloath, and put into it almost halfe a cup of victriall beaten to a powder. A Booke of Secrets (1596) p. 5

Gum Arabic, a gum from the acacia tree, was used as a binder for the ink; “victriall” (vitriol) was nothing more than iron sulfate, obtained from passing water through “sulfurous earth” and exposing it to iron.  The resulting ink has a bold blue-black appearance, though it fades to brown as manuscripts age.  Many of the world’s finest artists employed gall ink in their drawings, Rembrandt and Van Gogh to name two, and composers like Mozart regularly used it for their musical scores.  The permanence of the ink is demonstrated by the masterpieces that remain for us to enjoy today.

If apples are fruit, then oak apples are not—since they do not contain seeds.  That being the case, what causes oak apples to form?  The answer lies with a tiny wasp, Amphibolips confluens.

In early summer the wasp deposits its egg on a young leaf.  The egg and the larva that grows from it secrete plant growth substances that compel the oak to make the oak apple.  After growing inside its comfortable chamber, the young wasp emerges to find a mate—both sexes are produced in equal numbers.  After mating, the females crawl down the trunk to lay their eggs on the roots of the host oak tree.  The young that hatch are all females,–a completely new generation!  They spend the winter underground, feeding casually on the roots as needed, but mostly remaining dormant until the weather warms.   When the young oak leaves are just the right size, they ascend the tree trunk to lay their eggs, thereby completing the life cycle.

Collection of pea size galls
Collection of pea size galls

Oak apples are not the only galls formed on oaks.  In fall in Northern Michigan white oaks shower the ground with pea-sized leaf galls, each one carrying a larva wasp.  Acorns and twigs harbor still more galls, all caused by the same family of wasps, the cypnids.  It is hopeless to wipe them out, the two species, wasps and oaks, having evolved together for untold generations.  Besides, who would want to?  Galls are fascinating objects and useful, too.  Won’t you find a tree full of oak apples and make your own ink this summer?

Richard Fidler is co-editor of Grand Traverse Journal.

Horsetails and Snake Grass: Relics Before the Dinosaurs

fidler-snakegrassforest
A veritable forest of snake grass, or horsetails.

We have all seen them, on the beach or in ditches, but we walk on past them without a thought.  If we know them at all, we call them “snake grass” for their banded stems lacking apparent leaves.  As kids, we  pulled them apart at the joints, noting the empty, hollow canal that runs up the center.  Hollow stems suggest many uses to children—whistles, building materials for sand castles, girls’ hair ties, toothpicks, and more.  Not having lost the capacity for play, they find much to do with the things we have come to ignore.

Not that all adults ignore them.  Campers recognize one species as a choice pot scrubber out in the woods, the scouring rush, Equisetum hyemale.  Its stiff ridged stems take grease and dirt of pans without shredding.  Players of instruments like the bassoon and oboe prepare their reeds with strokes of the scouring rush and craftsmen in Japan use it for a fine sandpaper.

Snake grass, or horsetails as they are known by many, get their roughness and strength from silica in their stems—you can see the tubercles with a ten-power lens.  Some species have more than others: one, the Smooth Horsetail, scarcely has any at all.

The Dutch find value in horsetails, mostly in maintaining the dikes that keep their land dry.  The plant has deeply rooted rhizomes (horizontal underground stems) which bind the soil, a helpful aid in reinforcing walls that keep the sea out.  A weed anywhere else, it is an asset in Holland.

fidler-horsetail
The roots of a horsetail plant the author carefully revealed from the swampy depths.

The common name “horsetail” requires explanation since the above-ground parts of the plant in no way resembles any part of the horse’s anatomy.  If you have the patience to dig down into the mud out of which the horsetail species known as “pipes” grows (and, I confess, I did just that at some sacrifice of blood to mosquitoes), you can discover how they came to take on the “horsetail” name.  The rhizome is jointed just like the stem, and out of each joint a tuft of roots grows–which, in aggregate, look pretty much like a horse’s tail.  Perhaps “snake grass” is the more reasonable name given the difficulty with exposing the “tail.”

A less common species of snake grass, or horsetails, Equisetum sylvaticum has a lacy appearance.
A less common species of snake grass, or horsetails, Equisetum sylvaticum has a lacy appearance.

Horsetails are not particularly successful as green plants go: they consist of one family with one genus and only a scant 15 species.  Michigan has eight and all of them be found in the Grand Traverse area.  Always they seem to prefer wet places—ditches, beaches, swamps, and marshes.

Horsetails were not always the weak sisters of the plant world.  Giant members of the horsetail family that reached heights of 45 feet are preserved in the coal beds of Pennsylvania and elsewhere.  Before the dinosaurs, before the flowering plants, they dominated the land in variety, abundance, and sheer size.  Alas for them, they now grow in neglected places separated from the great ecosystems of hard and softwood forests, plains and desert, tundra and bog.

Seed-producing plants won out in the long run, the conifers, hardwoods, and grasses occupying the greatest stretches of land.  Horsetails make spores, those produced in small cones that lie at the tips of the shoots.  They drift about in the wind, the luckiest ones arriving at a moist warm place to grow.  There they grow into miniscule green bodies that produce eggs in one place and sperms in another.  The sperms swim to fertilize the egg—and a new horsetail is born.  However, horsetails can avoid the whole process by having a piece of the rhizome break off and root elsewhere.

A common version of horsetail in the Grand Traverse region, E. Ferissii, the bane of beach owners.
A common hybrid of horsetail in the Grand Traverse region, E. Ferissii, the bane of beach owners.

Horsetails—snake grass–are not esteemed by those who wish to keep their beaches well-groomed.  Their roots are hard to tear out—remember the Dutch and their dikes?—causing them to reappear after great effort has been exerted to remove them.  Still, we should appreciate their good qualities: they scour, they sandpaper, they can be tied.  Not only that, they provide a glimpse into a different world 350 million years ago.   If you see a millipede hanging out among the stems of horsetails, you might be looking out on a scene enacted 380 million years ago.  Horsetails deserve our respect for their venerable age.

Richard Fidler, when not elbow-deep in swamp mud,  can be found editing “Grand Traverse Journal”.

Growing Your Own House: The Mites of Maple Bladder Galls

In early summer you may have noticed small pouches on red and silver maple leaves.  If you open one up, you will find—nothing at all.  Or so it seems.  In fact, the creatures that live there are swarming all around.

They are microscopic mites of the eriophyid family, so small you would need a 400X magnification to study them in detail.  Unlike most mites, they have but four legs—not eight—with two pairs clustered around the animal’s mouth.  Dwelling within such a small space, eriophyids hardly have need of legs at all: for most of their lives their universe is no bigger than the gall they inhabit.

The life cycle of the mite is simple.  They mate and reproduce within the secure enclosure of the gall, producing several generations within a summer.  Before leaves change color in autumn, obeying a signal we do not know, they migrate out of their chamber to the bud scales of next year’s leaves or to protected areas under loose bark.  Dormant, they wait there for the cold blast of winter.

In spring, before leaves expand, they enter young leaves on the underside, their presence initiating the balloon-growth of many pouches, the number ranging from a half dozen or so to an ugly multitude that deforms the leaf.  While the mites undoubtedly sap energy from trees, they cause little permanent damage.  Gardeners and foresters generally ignore their presence, not wasting effort or chemicals to discourage them.

Maple Bladder Galls on Silver Maple, Traverse City.
Maple Bladder Galls on Silver Maple, Traverse City.

I think leaves adorned with crimson maple bladder galls are attractive, resembling miniature Christmas decorations in the month farthest removed from that holiday.  They can be pointed or inflated depending upon the species of mite involved and colors vary, frequently starting off green and becoming red before fading to a dull brown.  Can they be thought of as a rash trees get?  Not exactly, since they do infect the surface tissues alone, unlike human dermatitis.

Another kind of eriophyid attacks plants in a different way.  Instead of making galls, it secretes a chemical that induces plants to grow a forest of slender hairs called an erineum.  An erineum—taken from the Greek word for fleece—can be found on the lower surface of leaves of many plants: oaks, maples, viburnum, and grapes are especially affected.  It may appear as a velvet fuzz, white or commonly red in color.

As with the gall-forming eriophyids, the erineum mites are exceedingly difficult to see even with a powerful magnifier.  A twenty-power lens might reveal their presence, though sharp eyes will be called for.  A microscope, of course, would work better.

Somehow I connect these animals with larger herbivores like bison..  I imagine them roaming over the fields of hairs they caused to grow, feeding upon them as the bison would, a prairie in a square inch.   Throughout early summer they graze, finally retiring to bud scales and bark for the winter.  Occasionally a stiff wind will blow them right out of the erineum, something bison do not have to worry about.  Of course, the advantage for the mite is that it might get blown to a new tree, fertile ground to establish a new miniature prairie ecosystem.

Nature performs its work at every scale: planet, ecosystem, organism, organs, tissues, and cells.  Isaac Asimov, the famous science fiction writer, once wrote about exploring the world extending from his backdoor.  After much study he had gotten as far as a few feet from his porch, so numerous were the species he encountered.  Most likely he did not get around to the mite-formed galls or erineums on his shade trees.

Richard Fidler is a retired teacher of biology, a Traverse City historian and an editor of the Grand Traverse Journal.

The Forest that is Traverse City

The Forest That Is Traverse City

In summer, preparing to land in Traverse City, it is hard to see the houses below through the airplane window.  A vast forest spreads out there, obscuring houses and streets alike.  It is a forest of a sort, yet it resembles no forest growing wild nearby.   Local forests do not have sycamores, tulip trees, Japanese lilac, Norway maples, and Gingko.   Nor do they have Colorado Blue Spruce and Norway Spruce.  All of those trees are exotics, having been planted by individuals or by the City Parks Department to provide shade as well as grace and beauty to the city landscape.  They are native to other lands, some as close as Southern Michigan and others as distant as Tibet.  Whatever their lineage, they have found homes along the streets of Traverse City.

The mixture of white pines, red pines and oak at the NMC campus represent the forest of most of Traverse City before white settlement.
The mixture of white pines, red pines and oak at the NMC campus represent the forest of most of Traverse City before white settlement.

Before there was Traverse City, there was forest.  Most of the city was built upon level, gravelly lake bottom, its sand still visible whenever sewer projects require excavation.  The great White Pines grew there, along with a scattering of Red Pine and White and Red Oaks, a mixture still in evidence on the Northern Michigan College campus.  The pines were the first to be taken by the Hannah Lay Logging Company, while the oaks were generally left alone.  Some of them remain today in the back yards along the streets of both the east and the west sides of town.  Oakwood Cemetery is home to many.

The far west side of town provided different habitats for trees.  Along Kids Creek, from Meijer’s to the Boardman River, a vast swamp covered the land.  Street names like “Spruce” and “Cedar” were named after the trees that grew nearby.  Early in the city’s history, the Creek was dammed to make a mill pond at a location near the Kids Creek viaduct under Division Street.  Valued by young potters even now, the clayey soil of the area still can be seen along the stream banks.

Relic huge beech trees on Monroe Street occupy sites on the West side of town. They prefer the richer soils of moraines.
Relic huge beech trees on Monroe Street occupy sites on the West side of town. They prefer the richer soils of moraines.

Finally, ascending the hills that border the west side of town from the Commons to Hickory Hills, the forest changes again.  Giant beech trees inhabit this area, some admirably cared for by homeowners who apparently do not mind the beechnuts, hollow trunks, and occasional breaking of dying branches under winter snow.  Hard maples–sugar maples–grow along with them, the two species forming most of the canopy of a beech-maple forest.  Soils here are richer than those of the city’s flatlands: Glaciers deposited more clay, enabling higher soil moisture and faster growth during dry summers.  The large trees of Ashton Park near Willow Hill School are examples of the virgin hardwoods that occupied this forest of glacial moraines.  Repetitions of these beech-maple forests can be seen throughout the hilly regions of the Grand Traverse area.

Most trees growing along streets are not relics of the primeval forest that city founder Perry Hannah knew.  They have been planted by the City and by townspeople in an effort to make the barren landscape more hospitable to early residents.  Early photographs show an empty landscape from the Bay to the hills surrounding the city.  The sun burned hot in summer and a heavy rain would send streams out of their banks without the trees to hold back run-off.  It was only natural people would try to restore what loggers had taken from them.

James Decker Munson started the arboretum in front of Building 50 at the Commons. Plaques describing tree species still remain.
James Decker Munson started the arboretum in front of Building 50 at the Commons. Plaques describing tree species still remain.

Centered in large cities like Chicago, the City Beautiful Movement began in the early twentieth century as a response to industrial pollution and environmental neglect.  It promoted the segregation of railroads and factories from residential spaces, city parks, sidewalks, and the planting of trees along broad, paved streets.  Influenced by the movement, Traverse City set about making its streets beautiful.  It laid out Hannah Park at the present location of the Carnegie library (now, the History Center) on Sixth Street and began planting trees, sugar maples by the hundreds.  Early photographs of the library show rows of thin saplings bordering the street.  Most have disappeared to be replaced by other—perhaps more fashionable—trees.

According to Rob Britten, City Parks and Recreation supervisor, the city chooses its trees carefully, attempting to harmonize diversity with resistance to the abuses of city living, all the time paying attention to rate of growth, sturdiness, and the attraction of flowers, fruit, and colorful leaves in autumn.  It is not an easy job.

No longer emphasizing sugar maples, the City plants a wide variety of species: Japanese silk trees, Ginkgos, Hackberry, Autumn Blaze (a cross between sugar and red maples)—even Chinese pears, downtown and elsewhere.  The harmful consequence of depending too heavily on one tree species is visible in the demise of ash trees through the depredation of the Emerald Ash Borer.  Healthy ashes along city streets are doomed to an early death due to the insect.

Even without attacks by insects, life is hard for trees in the City.  First, there is the broiling sun in summer.  On sunny days black asphalt heats the air above it, raising temperatures far higher than those experienced by nearby trees in the forest.  Winter salt dehydrates roots, conifer needles, and buds.  Add to that the confinement of roots by paved surfaces and it is a wonder they survive at all.  But they do and we are grateful.

The white oak trail-marking tree on Washington St. near the Courthouse reflects the forest of 165 years ago.
The white oak trail-marking tree on Washington St. near the Courthouse reflects the forest of 165 years ago.

Trees enrich our lives in so many ways.  They cast shade and cool our houses.  They turn colors in autumn, bringing us joy even as we contemplate the return of winter.  They make fruit of many kinds, enjoyed by animals that normally spend their lives in wilderness.  They provide homes for birds, squirrels, and other mammals, thereby giving us a glimpse into their lives.  Most important of all, they connect us city dwellers to the rhythms, textures, and beauty of Nature, a perspective that comes easy to the farmer but not to us.  Leaves and twigs, roots in sewer pipes, pollen in spring, a downed tree in a wind storm—it is all worth it.  Imagine the barrenness if they were not there.