Sunday, Sweet Sunday

sun through fogSunday is my favorite day of the week.  That’s because traffic is light on Interstate 99 at the base of our mountain on the Logan Valley side and the industrial-sized limestone quarry on the Sinking Valley side is closed for the day.  Other businesses are also quiet, and I revel in the peace of “Sunday, Sweet Sunday” as the song goes in Rodgers and Hammerstein’s “Flower Drum Song.”

Of course, the trains still whistle at every valley crossing, including our own, a sound that dates back to 1850 when the main line from New York City to Chicago was built through the gap at the bottom of our mountain. Once folks lived in a small, iron forge village next to the rail line where we have built a parking lot for our hunters.

When we moved here back in 1971, the cellar holes of four dwellings were popular bottle-collecting areas.  Even today, a few of the people who lived in those homes as children, nostalgic for the sights and sounds of their youth, sometimes visit and set up lawn chairs to watch and listen to the trains.  It’s a sound they have adapted to and enjoy.

Despite my 37 years here, I have not adapted to the clamor from the valleys.  Increasing noise pollution, especially in midsummer when all our windows are open, has forced me to wear ear plugs at night.  I wonder, along with nature writer Joseph Wood Krutch, who wrote in the mid-twentieth century, “How long will it be before… there is no quietness anywhere, no escape from the rumble and the crash, the clank and the screech which seem to be the inevitable accompaniment of technology?”

But this sweet Sunday in late July is almost silent as we sit on our elevated front porch among the trees, warmed by the rising sun, and enjoy my husband Bruce’s cornmeal/whole wheat waffles.  Serenaded by song sparrows and a tufted titmouse, we are entertained by the antics of a family of red-bellied woodpeckers that recently fledged from a nearby black locust tree.

On this day, I choose to walk beneath the filtered, green light of Black Gum Trail.  Already the spined micrathena spiders are spinning their orb webs across the trail, and I stop frequently to carefully pull aside a couple anchoring strands of silk so I can avoid their entangling webs.  Fresh coyote scat and not so fresh bear scat provide ample evidence that I am not the sole user of this deep woods’ trail.  The only persistent singers this late in the summer are the low-keyed, monotonous red-eyed vireos and eastern wood pewees.

gypsy moth cocoonsScarlet tanagers have replaced their hoarse, robin-like songs with their “chit-bang” warning call, and I hear several during my walk.  Once I sit and watch a male scarlet tanager foraging for caterpillars on the top of black gum leaves, flying from tree to tree and flashing his black and red colors like some exotic tropical bird.  Insect damage riddles many of late spring’s perfect leaves and a handful of black gum leaves have turned red and pink, which reminds me that autumn isn’t far off.

I see a few gypsy moth egg masses on chestnut oaks and am also reminded of a new term I learned the other day — throughfall — which is defined as all the stuff that rain washes down on the forest floor from the foliage above such as insect frass, bodies, and leaves.  Although the term was applied to the rainforest, such a concept is also important in our forest.

At the end of Black Gum Trail, I pick up Rhododendron Trail where white-breasted nuthatches “yank” and chipmunks “chip” and “cuck.”  In the distance a black-throated green warblers sings while a slow, propeller plane drones noisily overhead, momentarily disturbing Sunday’s peace. Unfortunately, even deep in our hollow, I cannot escape the technological sounds from above, such as frequent helicopters, jet fighter planes, and private airplanes that fly over or along our mountaintop.

As I wend my way past the many tall rhododendron shrubs for which the trail is named, black-capped chickadees scold.  I notice that most of the shrubs’ flower heads have set seed.  Because of our vacation in Newfoundland, I missed their blossoming, but it must have been glorious.  The trail edges its way past a steep, mossy hill covered with three-year-old rhododendrons.  They are shooting up fast–a result of our deer management program that encourages our hunters to harvest more deer to improve the health of our forest.

I descend Laurel Ridge on Rhododendron Trail and near the stream, Acadian flycatchers call “pit-see.” On our gravel road, five deer snort and bound up Sapsucker Ridge.  Beds of wood nettle (Laportea canadensis) bloom beside the stream, a species that has only recently appeared on our property and one that botanists claim is a favorite of deer despite its numerous stinging hairs.

longhorn on wild hydrangeaOn the other hand, the deer I disturbed have been dining on wild hydrangea, especially the young shrubs growing on the road bank.  They have also been snacking on jewelweed and Virginia creeper.

But other wildflowers are untouched such as the clump of Indian pipes and sprays of black cohosh.  Common enchanter’s-nightshade (Circaea lutetiana) has sent up racemes of tiny white flowers that have already turned into green stick tights at their bases.  Named for the enchantress Circe, I assume the name honors the delicate flowers and not the bur-like, bristly fruit that clings to animal fur and pant legs.

The road is a highway of deep woods’ butterflies this cool, clear, summer morning.  Red-spotted purples flutter past.  These blue-black butterflies flash an iridescent blue on their hind wings and are named for red-orange spots on their undersides.

spicebush swallowtail shadowSpicebush swallowtails bask on the road.  They are the same blue-black with iridescent blue on their hind wings as red-spotted purples, but they sport elegant tails and the edge of their wings has a line of large white dots.

Spicebush swallowtail caterpillars, as their name implies, feed on spicebush leaves and also on sassafras tree leaves, whereas red-spotted purple caterpillars prefer the leaves of black oak, black cherry, poplar and aspen. Both have caterpillars that resemble bird droppings.  Those of the red-spotted purples are grotesquely horned; those of the spicebush swallowtail only look like bird droppings in their first three instars.  Then they turn bright green with large yellow and black eyespots that mimic snakes.

I am surprised to see a great-spangled fritillary basking on a sunlit leaf because usually I see these showy, orange and brown butterflies in the fields.  On the other hand, their larvae dine on violets.  Sometimes the female butterflies, which lay as many as 2000 eggs per butterfly in the fall, manage to lay at least a few of those eggs on violet leaves.  Their orange-spotted black caterpillars, bristling with black spines, hatch two or three weeks later, drink water, but don’t eat until the following spring when violet leaves appear.

royal walnut moth 2

My best winged discovery of the day, though, is a regal or royal walnut moth (Citheronia regalis) lying on the road.  It is alive but unable to fly.  This large, spectacular moth has a fat, orange body horizontally striped in yellow, yellow-spotted, orange-veined gray front wings and orange hind wings patched in yellow. But it is better known in its caterpillar form as a hickory horned devil, armed with outsized, orange and black horns on a knobby, brown body that turns lime-green shortly before it pupates.

Once common as far north as Massachusetts, it is now primarily a southern species ranging from New Jersey to Missouri and south to Florida and eastern Texas.  Its caterpillar consumes a wide range of food plants such as ash, butternut, cherry, cotton, hickory, lilac, pecan, persimmon, sumac, sweet gum, sycamore, and walnut leaves.  Because this is a new species for our mountain, I carefully pick it up, place it on a leaf, and carry it home so our son Dave can photograph it.

royal walnut moth 1My sweet Sunday ends as peacefully as it began.  As we sit on the veranda in the evening, I watch the mulch heap near the barn through my binoculars.  Bruce has trampled down the field grasses in front of it to give us a ringside view of our pugilist woodchuck and its chief rival.  The evening before I had heard growling and squealing and had gone down to the mulch heap to see what was making the commotion.  A woodchuck emerged from the weeds with a pawful of something and sat on its rear end to eat it, giving me what could only be described as a baleful, defiant look.  That woodchuck was a fighter even though it was smaller than its portly opponent who feeds every afternoon on the barn bank grass.

This evening the small pugilist appears first, sitting on its bottom and beginning with a moldy, whole wheat tortilla that it holds in its front paws as a child would.  But soon the corn cobs are too much for it to resist even though we thought we had cleaned them thoroughly.  Picking the first cob up, it holds it horizontally in its front paws and systematically gleans what bits of kernels are left.  All the while, it is on high alert.

As it starts on its second cob, the fat woodchuck emerges from its den under the barn to eat grass on the barn bank.  Then it lifts its head, sniffs in the direction of the mulch heap, and barrels toward the tasty leftovers.  The pugilist, still gripping its second cob, disappears in the opposite direction.  Its protagonist hunkers down on all fours to chow down, unlike its rival.

But unlike the previous night, the woodchucks preserve the Sunday peace.

All photos were taken on the mountain by Dave Bonta (move cursor over them to read the titles, and click on them to see at larger sizes). The last two show the very moth described here.

Mad Marmots

“Danger–Mad Marmot” warned the sign on the laboratory door. Inside stuffed woodchucks and other woodchuck memorabilia cover Stam Zervanos’s desk and study area.

Zervanos, a biology professor at Penn State University’s Berks-Lehigh Valley College near Reading, has been studying woodchucks, the least social of the marmot genus, for eight years. As a physiological ecologist, he is particularly interested in woodchuck hibernation.

Using radiotelemetry to continuously monitor the body temperature of hibernating woodchucks, Zervanos discovered that even though they go into deep torpor, they awaken every week or ten days throughout the winter, but unlike chipmunks, which also awaken from deep torpor, they don’t eat stored food. Instead, Zervanos speculates that such arousals in woodchucks may be necessary “to maintain muscle integrity, especially in males, which must be in top form coming out of the den.”

They arouse fairly quickly and are awake from a few hours to half a day. Then their body temperature, which reached its normal 96 degrees Fahrenheit, goes back down to its hibernating 47 degrees or so more slowly than it went up.

Males, though, are awake for longer periods than females, especially near the end of hibernation, and their body temperature, when hibernating, is higher, so they use 38% more energy during hibernation than females. Males also enter hibernation five days later than females and arouse for the last time three days earlier.

Most importantly, for those who might scoff at Groundhog Day and Punxsutawney Phil’s annual weather predictions, “In spring, most woodchucks [also known as groundhogs] emerged above ground two to four weeks before their last torpor bout with a mean date of emergence [being] the fourth of February,” Zervanos writes in a recent paper. That’s mighty close to Groundhog Day on February 2. And woodchucks may indeed be “sampling the external environment,” adds Zervanos.

But they are also sampling each other. The males visit female burrows, and the females remain at home to receive them. No hanky-panky is involved however, only “bonding activity in preparation for mating,” Zervanos says. These normally solitary animals need to reacquaint themselves with their neighbors because woodchucks do move around depending on their age, sex, or even inclination. And females far outnumber the males in part because in late winter and early spring, when cover is scarce and predators are hungry, the more active male woodchucks are easier for predators to catch.

In early February males also survey their territories while females assess the availability of food. Then both sexes settle into a final bout of deep torpor that lasts until early March. Only then do they mate. Their two to eight young are born a month later.

All this and more Zervanos and his research assistant June Brown have learned at their 60-acre study site–the Pieffer Farm on the campus–where approximately 30 woodchucks live. This mixture of woods and fields provides ideal habitat for them. So does the rest of the campus. During our visit in mid-March, Brown showed my husband Bruce, our son Dave, and me woodchuck holes in front of the campus bookstore, under the sundial near the library, and, most appropriately, in front of Luerssen Building where Zervanos has his office.

From there we followed June through the large trees that encompass the Nature Area of the Berks-Lehigh Valley College to the busy, two-lane Broadcasting Road, which we crossed to reach the Pieffer Farm. That road, as well as foxes, hawks, and the occasional coyote, accounts for the deaths of some of Zervanos’s subjects. Brown said that all of the previous year’s young were still in the study area because they had taken over a big male’s separate burrows after a fox killed him. Usually most juvenile woodchucks disperse in their first year in Pennsylvania.

But Christine Maher, a biology professor at the University of Southern Maine in Portland who is also studying woodchucks in the field, has discovered that in her study population as many as half of the juveniles, both male and female, delay dispersal until their second summer and a few even delay until their third summer. Her females are two years old when they mate, but most of Zervanos’s are yearlings.

Maher has also found that woodchucks are more sociable than previous studies have shown. Her male and female adults, she says, often interact outside their breeding season, and her female adults build burrows near their mothers, while males move away.

The date of Groundhog Day doesn’t make as much sense at Maher’s latitude. She first sees adult male woodchucks above ground around March 3 and the first adult females on March 25. Most of her woodchucks also go into hibernation in late September, a month or more before Zervanos’s woodchucks.

All of Maher’s woodchucks hibernate; 10% of Zervanos’s don’t, and farther south, a colleague at Clemson University in South Carolina has found that few of his woodchucks hibernate. Is there a genetic basis for hibernation, Zervanos asks. If Maine and South Carolina woodchucks were brought to Pennsylvania, would their hibernation patterns change? Zervanos calls this a “common garden experiment to see what effect environment has on genetics,” and he hopes to find out. The study of hibernation may also yield some medical insights or applications, Zervanos says, since deep torpor seems to interrupt the activities of viruses, and possibly of internal parasites also.

Woodchucks can even enter deep torpor in the middle of summer to conserve water and energy, as Zervanos found out during the drought and heat wave of 1999. Five of eight of his radio-telemetried woodchucks did this. The three that didn’t lived close to water.

No matter what discoveries he makes about woodchuck behavior, Zervanos, like Maher, has found exceptions to the rule. For instance, one female traveled 360 feet over snow to enter a male’s burrow and stayed several days before returning to her burrow. (Maybe she thought it was leap year.)

Another female, more aggressive and antisocial than most, moved off into the woods and didn’t hibernate for two years. She also didn’t bear any young. Only when she hibernated, in her third year, did she give birth.

Brown, a dedicated observer who spends many hours watching individual woodchucks through binoculars, told us that some woodchucks have placid dispositions and others are unremittingly hostile. Last year two juvenile males shared a burrow even though most woodchucks are solitary creatures. She watched another woodchuck chase a hawk even though hawks usually chase (and eat) woodchucks.

As a casual observer of woodchuck behavior, I have watched a woodchuck chase a cottontail rabbit and have twice watched woodchucks fight. But probably my closest encounter with woodchucks occurred late last September when I was writing this column in my study.

I heard bumping noises down in the kitchen, but I thought it was our son Dave getting himself an early lunch. When I went downstairs to the kitchen to put the soup on, a small woodchuck dashed past me.

I slammed the door between the dining room and kitchen and yelled to Bruce, “There’s a woodchuck in the kitchen.”

Bruce propped open the back kitchen door and then hunted around our small kitchen for the creature. Finally, with the help of a flashlight, he found it hiding under the refrigerator.

He pried off the refrigerator’s bottom front panel and the woodchuck didn’t move. After considerable gentle prodding with the broom handle, the woodchuck suddenly ran out from beneath the refrigerator and on out the back kitchen door.

That woodchuck had been unusually curious all season, knocking over our walking sticks on the veranda, poking about on the back steps, and eating directly beneath our bow window. It lives, as far as we can tell, beneath our front porch where woodchucks have maintained a burrow system for decades and never before bothered us.

But how did it get into our kitchen? At first, we thought it had found an entrance through the foundation and into our basement, climbed up the basement stairs through the open door into our dining room and on into the kitchen the same way Carolina wrens did during the bitter January of 1993, but that hole, Dave reminded us, had been blocked off. And even though we searched the basement, we couldn’t find any other holes.

That evening, as Bruce was settling down to read in the living room, he called to me.

“Come here and see this.”

I could tell by the tone of his voice that he had something important to show me. He pointed to the screened window behind the piano. There was a hole in it. The piano itself had several fresh scratches and some dirt on it. Our hardwood living room floor also had a couple long fresh scratches.

Not content to explore our veranda and back porch, the woodchuck had climbed up the table we have sitting on the veranda next to the window. It had then torn a hole in the screen and clambered through, landing on the piano. The loud thump I had heard was probably the creature tumbling off the piano and on to the floor. After casing the living room, it had wandered through the dining room and into the kitchen. Luckily, it had not climbed up any of our chairs or left any odiferous packages.

But why had it broken into our home? Surely not to give me a conclusion to my woodchuck column.

Maybe it was curious. Maybe it was looking for a place to hibernate. Maybe it was a Mad Marmot–crazy or angry or both.

But I have to agree with Zervanos who told us during our visit, “They’re interesting animals and the more I study them, the more I’m amazed at their behavior.”

We are too.

Wily Hole Digger

Forget Groundhog Day! It’s a scam. Around here most woodchucks don’t appear until March, although we have recorded them as early as February 25. But March is the official wakeup month for most Pennsylvania woodchucks and when they emerge they are interested in sex, not in predicting the weather.

First the males appear and wander from den to den in search of receptive females. Then, a couple weeks later the females unplug their den holes so the males can consort with them. After mating with one female, a male moves on to another. If a mating is successful, thirty-two days later a female gives birth to between two and nine naked, blind youngsters no bigger than an adult red-backed vole.

The young are born in their mother’s nest chamber, a part of her larger burrow system which can be as long as 50 feet and as deep as 12 and which also contains separate hibernating and latrine chambers. Both the hibernating and nest chambers are lined with dead leaves and grass.

Back on April 12, 1993 I watched a female woodchuck gather a mouthful of leaves and grass and carry it down into her burrow. Five days later I put my head down at the burrow entrance and listened. A continual series of piercing, high-pitched cries emanated from the burrow, a signal that the young had been born.

Trying to observe woodchuck burrow life has been difficult for biologists. Consequently, not much is known about their underground life. Mostly they live alone, hence their scientific name Marmota monax which means “solitary marmot.” The female raises her young by herself, a process that takes two months. At four weeks of age they open their eyes and are able to forage near the burrow entrance. At five to six weeks they are weaned and two weeks later they are on their own.

A popular woodchuck burrow at our Far Field thicket has been inhabited most years by a female woodchuck. On May 25, 1990 I watched two young woodchucks foraging in the weeds less than 15 feet from where I stood. They never did see me and for the first time I actually had a look at juvenile woodchucks.

Like all youngsters, they had cute faces, but they already possessed an adult’s alertness, several times leaping on to fallen trees to look for enemies in between shoving green stuff into their mouths with their dexterous front paws just as adults do. Finally the one closest to me turned around and trundled back toward the other young chuck who was foraging much nearer to the den entrance. It rushed toward its sibling and chased it down into the burrow. Then it took over and fed in the spot vacated by its less aggressive sibling.

At that same den, two years later on June 6, I surprised two young woodchucks and their mother foraging outside. She seemed unable to figure out where or what I was, but she lived up to her nickname “whistle-pig.” Sitting on her back haunches, she emitted a high-pitched whistle followed by a rapid, nine-syllable, lower trill described by William J. Hamilton, Jr. and John O. Whitaker, Jr. in Mammals of the Eastern United States as “softer chuckling notes.”

Her young immediately went down into the burrow, but she remained outside. Even as I eased myself from a kneeling to a sitting position, brought out and peered through my binoculars, and wrote notes, she continued her “whistling” call several dozen times with about seven seconds between whistles. Finally she retreated halfway down her burrow, still whistling until I left the area.

Whistling by woodchucks has been well documented. So has the growling and teeth chattering I’ve heard when woodchucks fight. But last March I heard an entirely new sound. I had surprised a woodchuck in the middle of First Field and it had run down into its burrow. Then, as I walked toward it, the woodchuck popped its head out to look around and I froze in place. Even though woodchucks are supposed to have excellent vision, I have learned that if I stand still and the wind is right, woodchucks will not see me no matter how close they are.

Up and down like a periscope its head went as it slowly peered in every direction for many long minutes while I watched from 25 feet away. Then the wind picked up, clouds totally blanketed the formerly cloudless sky, and the thermometer dropped like a bomb. Still I watched as the woodchuck, after many more “up periscope” looks, eased most of its body out of its burrow. By then I was chilled to the bone so I walked deliberately toward the creature. It dove down into its burrow. As I reached the burrow entrance, I heard a loud noise coming from underground that sounded like a whinnying horse. None of the sources I later checked mentioned such a noise.

In fact, except for the volumes that have been written about Groundhog Day, woodchucks have not been a popular subject with nature writers, journalists, or biologists. I must admit that they have been my least-favorite wild creatures too, especially during the years when we had a large vegetable garden and no dog. No matter how deeply we buried our nine-foot-high garden fence and weighted it down with rocks, woodchucks always managed to dig under it. One spring a single woodchuck ate 50 broccoli and cauliflower plants in half an hour. Another summer our son David tried to defend his garden by shooting every woodchuck he caught inside the fence. After 25 deaths, he gave up.

Now that we buy our vegetables at the local farmer’s market we are able to appreciate the horde of woodchucks who live everywhere on our mountain–in the deep woods of the hollow, the dry oak forests on both Sapsucker and Laurel ridges, the First and Far fields, and the several mountaintop thickets. Furthermore, at least five live in the vicinity of our house–under our front porch, below the back porch in the grape tangle, beside the garage, next to the road drain, and under the guesthouse.

I’ve found them outside our back door investigating the doormat, tearing across our veranda while I sat nearby, and parading over the tiny guesthouse front porch. They graze on our roughly shorn lawns and our flower beds and even eat the crownvetch we foolishly planted on the steep back slope shortly after we moved here. Like white-tailed deer, woodchucks eat a wide variety of both cultivated and wild plants, but they also occasionally relish grasshoppers, snails, June beetles and other invertebrates.

Before Europeans settled America, a much sparser population of woodchucks lived in the woods. Not only was it harder for them to make a living in such a habitat, it was difficult to escape their major predators–black bears, mountain lions, wolves, and fishers. Then settlers cut down the forests, eliminated the large predators, and planted succulent crops of alfalfa, clover and other woodchuck-friendly foods. The living was (and is) easy except for the occasional woodchuck hunter, car, or smaller predators such as dogs, foxes, minks, weasels, large hawks and owls. However, woodchucks fight so fiercely when they are cornered that such predators often retreat.

Researcher Robert Snyder has also discovered that woodchucks are susceptible to many of the same diseases as humans are–hepatitis, liver cancer, arteriosclerosis, heart attacks, strokes, even high blood pressure, so they have become popular drug-testing laboratory animals. Nevertheless, there is still one woodchuck for every five to ten acres in the Northeast and the all-time woodchuck population explosion occurred at Letterkenny Ordnance Depot near Chambersburg back in the 1950s when Snyder and others estimated that 9,000 woodchucks lived on 10,000 acres.

The woodchuck population density on our homegrounds is even higher. We’re talking five dens on less than an acre. So we occasionally witness what we assume are turf battles in late spring and early summer when youngsters are looking for new homes.

On June 11, 1991 at 2:25 p.m. I watched from the upstairs bathroom window as a large woodchuck chased a smaller one up the driveway, grabbed it briefly, and tried to tussle before it broke away and tore across the lawn toward the grape tangle. The larger woodchuck pursued it halfway across the lawn and then reared up on its haunches to look around before lowering itself and trotting back up the driveway headed for the garage.

The following May, as I sat on the veranda in mid-afternoon quietly writing, I was suddenly interrupted by the fighting of two adult woodchucks six feet away in the grass off the end of the veranda. It looked as if the front porch woodchuck was defending its territory from the grape tangle woodchuck.

When I jumped up, the woodchucks growled loudly at each other before separating. One ran under the front porch while the other dashed the length of the veranda and around the back of the house to the grape tangle. Once again the grape tangle woodchuck had gotten the worst of the fight, although I had no way of knowing whether it was the previous year’s grape tangle woodchuck or a new resident.

Last May, our son David heard growling under the guesthouse in mid-morning and went outside to investigate. One large and one smaller woodchuck emerged from beneath the house fighting and ended up in the stream. As David watched, the larger one beat up the smaller one and then headed back toward the house. When it saw David it took off down the road, water streaming from its coat. In July he witnessed another fight near the guesthouse. That time the vanquished chuck climbed a tree.

That July fight was the latest one we have watched. By mid-summer woodchucks are more interested in eating than fighting. Then they seem like gluttons as they shove food into their mouths with jerky movements that remind me of a Charlie Chaplin movie. By late September our woodchucks look like obese shag rugs. Such eating is necessary, though, because they must increase their weight at least 30% before they move into their dens, plug all the entrances with dirt, curl up into a ball in their hibernaculum, and sleep for four or more months.

Although the latest date I have recorded a woodchuck abroad is November 13, most are hibernating by late October. Along with bats and jumping mice, woodchucks are true hibernators. Their body temperatures drop to 40 degrees Fahrenheit, their breathing slows way down and their hearts beat only four times a minute. Because of the earthen plugs, their dens remain a snug 56 degrees no matter what the temperature is outside.

It’s ironic that woodchucks are the center of attention on Groundhog Day when most are still deep in hibernation. On the other hand, their ability to hibernate is their most interesting behavior characteristic. Instead of celebrating the fairy tale belief in their ability to predict the weather, we should celebrate their true ability to sleep away the winter.