April showers bring more than May flowers, and birds aren’t the only creatures producing fantastic choruses in the springtime. While birders will set their alarms for 5:00am in order to catch the rainbow of spring migrants arriving in Vermont, herpetologists – that is, aficionados of amphibians and reptiles – will spend the wee hours of the night up to their knees in muck and water to glimpse the bizarre courtships of frogs and salamanders.
Beating wings fill my view. The snow geese are stark white, and the black tips of their wings pulse in contrast with their bodies. Hundreds – no, thousands – of these meaty birds move in unison. They squawk and honk, thousands of calls melting into an urgent and persistent roar.
At least that’s what I envisioned.
I had never seen snow geese, but I set out confidently to find the birds. I wanted to feel the wind from a thousand birds taking off at once. I wanted to feel their thunderous calls in my chest. Continue reading
Staying warm in the winter is hard. Chickadees eat constantly in order to survive long, cold winter nights. Squirrels spend precious time and energy creating complex insulated nests. Deer browse on nutrient-poor twigs to get as many calories out of their surroundings as possible. Yet compared to fish and other aquatic organisms, terrestrial wildlife breathe easy – literally. As fish battle the cold through the long winter, they are steadily running out of oxygen.
by Carly Brown
A few weeks ago I tied my laces, donned my hat, and set off for a long run down Spear Street, from Burlington to Charlotte and back again. Partway through my run I saw it crossing the road without any signs of hurry, proudly displaying its black and rusty fur: the woolly bear (Pyrrharctia isabella). I immediately looked up to check for oncoming traffic, then dodged out into the road, lunged, and swiped the fuzzy caterpillar. Without breaking stride I carefully set it on the roadside it was moseying to. Some feet down the road I repeated my behavior. My mind clicked back to middle school when I learned that a long rusty stripe means a mild winter. Is that true? And what are woolly bears when they are not cute, furry, caterpillars? Never mind what passing cars must think about my woolly bear lunge.
The woolly bears that we see in the fall will overwinter as caterpillars under plant debris in the cold snow environment. In order to survive the winter chill, the caterpillars produce a substance, called a cryoprotectant, which acts much like antifreeze. When spring begins to show its face, the caterpillars emerge from the leaf litter, begin to eat new plant growth, and then form a pupa to eventually emerge as the Isabella tiger. This moth is a relatively nondescript yellow-brown moth with several darker spots on its wings. Woolly bears have two generations per year. This means that the newly emerged moth lays its eggs, which hatch to complete the cycle through woolly bear and moth in the summer. The eggs that these new moths lay will hatch into the woolly bears that overwinter.
Do these fuzzy caterpillars tell us something about the winter to come? The legend is that the longer the rusty brown stripe on a woolly bear, the milder the winter. Conversely, a narrow rusty band predicts a harsher winter. There have been a few attempts to correlate the size of the stripe with winter conditions. One of the most well known studies was by biologist Charles Corran in the 1940s. For the first few years of his study, the prediction of the woolly bear was correct, but there was more than enough evidence to disprove the common myth in the years to follow. Some suggest that the length of the rusty stripe may actually tell us something about the harshness of the winter and spring that occurred the year before.
I know deep down that the woolly bear myth is just that—a myth. That doesn’t stop me from doing a few extra lunges to save a woolly bear or two and check out the length of the rusty stripe. Curious about what this winter will bring? I suggest that you join me in the woolly bear lunge.
by Cathy Bell
(originally posted on vtdigger.org)
Back in the middle of September, a headline caught my eye. “Northeast Faces Devastating Pumpkin Shortage,” I read, with a mixture of amusement and trepidation.
Devastating? Really? Pumpkins are cheery and plump and orange. It’s tough for me to take them seriously enough to believe that anyone could possibly construe a shortage as devastating. Even the name—pumpkin—is irresistibly rotund and bouncy-sounding. Still, that headline got me a little worried. I have a tradition of throwing a pumpkin-carving party the weekend before Halloween. It’s always great fun to gather a group of friends together for a few hours of quality time with sharp knives and slimy pumpkin innards. What if there weren’t enough pumpkins this year?
Fortunately for pumpkin seekers, it appears that the forecast Great Pumpkin Shortage isn’t so devastating after all. If you drive through rural Vermont or stop by your local farmers’ market, you will see row upon row of happy-looking pumpkins offered up for sale. So what’s the story? Is there a pumpkin shortage or not?
To answer that question, I swung by my local farmers’ market in the Old North End of Burlington and checked in with Lauri Brewster of The Farm at Cold Spring in Milton. “It’s regional,” said Brewster. “Low-lying areas got hit hard. But we have plenty of pumpkins.”
Not all growers were so fortunate. Many suffered significant losses in the wake of Tropical Storm Irene. Mark Winslow of Winslow Farms in Pittsford reported that floodwaters destroyed about half his pumpkin crop. “Approximately 150 tons washed away. That’s $40,000 in pumpkins. Because of the loss, we are not able to deliver to our wholesale customers, though we still have an excellent crop for our farm stand.”
Montpelier’s Hunger Mountain Co-op has purchased Halloween pumpkins for over twenty years from a single grower, East Hardwick’s Riverside Farm, said produce manager Robert Kirigan. This year, about a third of Riverside Farm’s pumpkin crop was lost, so “we are a little short,” Kirigan admitted.
Despite having fewer pumpkins to satisfy demand, prices don’t seem to be any higher than usual this year. According to Kirigan, “Our pricing is the same as last year. Although normally shortages would tend to push the price up, we and Riverside Farm decided not to raise our prices. We wanted to encourage folks to buy real pumpkins, not plastic ones. And for the sake of the Earth we want them to be organic, not grown with chemicals. So holding the line on price seemed like the right thing to do.”
With fewer pumpkins around, some vendors turn to out-of-state growers to ensure fully-stocked shelves. Burlington’s City Market, though, specializes in stocking Vermont pumpkins, produce stocker Kara Brown said. “We buy them from about five different suppliers, some organic and some conventional. They’ve all definitely had a tighter supply than last year.”
Dire warnings of a pumpkin shortage hit the media a few weeks after Hurricane Irene inundated the East Coast, with news outlets including the Washington Post, CBS News, and the Wall Street Journal posting stories about the potential for a paucity of pumpkins this fall. Some pumpkin patches, like those of Winslow Farms, were destroyed outright by flooding. Even if they weren’t carried away by high water, pumpkins that sat in standing water are illegal to sell—a problem encountered by growers in Burlington’s Intervale.
Irene brought a longer-term, more insidious threat, as well. Lingering moisture in the fields created an ideal environment for the spread of a host of pumpkin diseases. Plants may not have to suffer through sore throats or stopped-up sinuses, but they can be afflicted with a wide variety of conditions including wilts, rots, and blights. Like us, they can succumb to onslaughts by bacteria, viruses, and fungi.
“It may be difficult to imagine,” write Purdue University plant pathologists Richard Latin and Karen Rane in their Identification and Management of Pumpkin Diseases, “but we receive more requests for information on pumpkin diseases and pumpkin disease control than on any other vegetable crop.”
Why pumpkins? The answer lies in what they are and how they grow. Pumpkins, of course, are squash. To a botanist, they’re members of the cucurbit family, related to cucumbers and watermelons. Most members of this plant family are vines, and pumpkins are no exception; they grow by sprawling across the ground. Their vines can lengthen by as much as six inches a day during peak growing season. This rapid growth means that pumpkin plants need rich soil and plenty of water.
The challenge is that too much water creates ideal conditions for pathogens that cause rot and decay. Particularly problematic are puddles that persist on the ground in the pumpkin patch. You probably know how disappointing it is to find a pumpkin that looks perfect from the top, but that has a big soft spot on the underside, sometimes with visible white mold. This is Phytophthora blight. The name is a mouthful, but it’s telling: “phyto” means plant in ancient Greek, and “phthora” means ruin or decay—so you can think of Phytophthora as the Plant Destroyer. There dozens of different kinds of Phytophthora; one, Phytophthora infestans, caused the Irish Potato Famine.
The species that infects pumpkins is called Phytophthora capsici, and it’s a tricky thing to fight. It used to be considered a fungus, but it has a few strange traits which have led taxonomists to reclassify it as an oomycete, in a different kingdom of life altogether. Like fungi, it spreads by producing spores. One kind, called an oospore, is round and thick-walled; it’s built to last and can persist in the soil for years. But Phytophthora’s other spore type, known as a zoospore or swimmer, is the fascinating one. Each swimmer sports two little whiplike tails that it uses to propel itself through water. The existence of these swimmers means that Phytophthora is more closely related to diatoms and marine plankton than it is to fungi.
There are other diseases that infect pumpkins, too, and many of them thrive when there’s a lot of late-season moisture, as there was this year. In fact, the susceptibility of pumpkins to disease, combined with strongly-seasonal demand (pumpkins are worth a whole lot less if they go to market on November 1), sets them up as a crop that has potential for shortages. Luckily, weather that creates ideal conditions for disease is usually localized. In any given year, there’s probably some region of the country that has a pumpkin production problem … but there are plenty of other pumpkins in the patch, if you’re willing to go a little farther afield.
That’s good news for those of us who are shopping for pumpkins, but small consolation for farmers who suffered losses during Tropical Storm Irene. “I just wish there was a real insurance program for specialty crops,” said Winslow. “We do not use the government program because our past experience is that it is completely inadequate.”
by Claire Polfus
It’s about that time. The leaves hug the forest floor rather than whisper to the wind in the canopy. The nights scatter a frosty pattern across my windows. The cool breeze tantalizes my toes with the anticipation of snowflakes and skis. And, it is dark. It is dark as I wait for the bus in the morning and as I make my way home in the evening. The days are getting shorter and the long nights of winter are starting.
Many of fall’s keystone changes are set off by the diminishing light. One of these is the changing fur of the snowshoe hare (Lepus americanus). Snowshoe hares look like large rabbits (although they are not all that closely related to the cottontails in our Champlain Valley backyards) with extra-large back feet, which they use to run on top of the snow in the winter and evade their predators. Their range extends from arctic tree-line through the extent of the North American boreal forest down to its southern reaches in the high elevations of Southern Appalachia and the Colorado Rockies. Everywhere you find snowshoe hares, you find snowy white winters. In order to camouflage themselves during the snowiest months, they molt from a dusky brown in the summer to a pure white in the winter.
In fall, the shrinking daylight prompts the hares to shed their outer layer of brown fur and regrow a new and more insulative white outer fur. The opposite occurs in the spring. While they are molting they are generally at higher risk for predation since they are both brown and white and can blend into neither snow nor ground. One of the most embarrassing sights you can see as you explore the woods in the fall is a white and brown hare frozen in place wishing and failing to be camouflaged against a backdrop of fallen leaves!
Thus far in the evolution of snowshoe hares, the advantages of camouflage in the winter have outweighed the heightened risk of predation in the spring and fall. Unfortunately for the hares, they evolved in a world where daylight and temperature aligned, at least on average, in a certain way. Since climate change is altering temperatures and precipitation but not day length, this alignment is becoming skewed. In Montana some researchers are finding that the period where the hare’s fur does not match its surroundings is lengthening. This is great for predators for the time being, but if hare populations become too deflated, the boom may become a bust for lynx, bobcat and great-horned owls.
Adaptation to changing seasons is necessary for every northern species. As I step out of my house in progressively warmer jackets, I know that the hares up in the mountains are becoming progressively whiter. Soon there will be snow and we will be racing each other across the mountain meadows – if I can find one first!
By Leah Mital-Skiff
I don’t want to make any controversial statements about whether it is easier to be male or female, but it is tempting in this case. When times are good on the forest floor, Jack turns into Jackie and when the going gets rough, Jackie turns back into Jack. We could say that Jackie likes to cruise during the good times, but her reproductive work requires a more nutrient-rich environment.
Jack-in-the-pulpit, Arisaema triphyllum, is hermaphroditic and begins adulthood as Jack, its male expression. After maturing past the seedling stage, the plant will produce male flowers on the spadix, the cylindrical reproductive structure commonly referred to as “Jack” and are buried deep inside the pulpit, covered by the hooded spathe. The musty-smelling spadix attracts gnats that enter through an opening in the base of the spathe and move up and down the spadix gathering pollen from the male flowers.
If conditions were ideal the previous year, elsewhere in the forest, another jack-in-the-pulpit stored enough energy to emerge this year as a female, producing female flowers. This growth takes a significant amount of energy and requires optimal conditions of light, nutrient availability and moisture. Thus, Jack will only emerge the next year as Jackie if the conditions are favorable. Jackie comes endowed with two sets of leaves in order to capture more sunlight and produce the energy she needs for reproduction. Male plants in a stressed environment will remain in the male form into the next year. Females under stress will revert to male and conserve energy.
Jack-in-the-pulpit is conspicuous in the early fall. The brilliant red fruits draw the eye from the changing canopy foliage in late September to the floor of eastern mixed hardwood forests. The bright red show on an autumn day denotes its success after many potential cycles between its male and female expressions to result in the production of fruits.
Perhaps the Jacks boast that they can tough out a nutrient-poor environment and wait out the bad times. Jackie then reminds us how much more energy is needed for her role in reproduction; males have the easy job of producing pollen-bearing flowers. In the end, the strategy of sequential hermaphrodism ensures more successful reproduction. In a stressed environment, the jack-in-the-pulpits in the area simply do not produce seeds. They conserve their resources and produce fewer seeds of a higher quality and viability for germination. When we see the brilliant red among the browning leaves of the fall, the story ends in success of gender synchronicity. The male plants have browned and wilted along with the other plants of the forest floor while Jackie boasts hermaphroditic success in a show of red to beckon the birds to disperse her seeds. Jackie does steal the show in the end.
by Doug Morin
I opened my backdoor and stepped into the yard to a flash of red and buzz of wings – a hummingbird. Maybe the last of his kind I will see this year, he perched on a small branch, tilted his head to either side, then flew off down the road.
Here in Vermont, hummingbirds disappear in late September and reappear in late April. We know the story well: birds fly south for winter. Of course they do. But, have you ever wondered why?
First, let’s turn the clock back a few thousand years. It turns out, most migratory birds in North America trace back to ancestors that lived in the tropics. Over time, these birds expanded their ranges until a small proportion eventually made it to North America. Even today, most birds arrive in late spring and leave in early fall – spending less than half their year in North America. The real question then isn’t, why do birds fly south for winter? but, why do birds fly north for the summer?
This is a particularly important question because migration carries a deep cost. It’s easy to discount the effort required to fly to and from the tropics, given the convenience of modern air travel (though I’d still like more leg room), but the journey for a bird takes huge amounts of time and energy as well as exposing the bird to unfamiliar environments and predators. The hummingbird in my yard, for instance, weighed only as much as small handful of paperclips, yet over the next weeks, it will first fly to the southern coast of the U.S., then across the Gulf of Mexico to the Yucatan Peninsula in a single, non-stop flight lasting nearly 24 hours, and finally overland to southern Central America.
The time, energy, and risk involved in migration have severe impacts: migratory birds are twice as likely to die in any given year, compared to tropical non-migratory birds. So, why in the world do they do it?
The answer is that the benefits outweigh even these high costs. Since relatively few birds come to North America, migrants have easy access to abundant insects, plants, and nesting grounds. With plentiful food and territory, migratory birds produce many more offspring each summer than their non-migratory counterparts. As winter arrives, however, insects and plants disappear, and the diminished food supplies (rather than dropping temperatures per se) drive migrants south.
Overall, migratory birds do not live as long as non-migratory tropical birds, but produce more offspring each year – resulting in nearly the same number of over their lives. Since the number of offspring determines how many birds will be in the next generation, these two strategies are roughly equivalent in evolutionary success.
So, the birds that grace our summers with color and song do so for windfall payoffs, but at immense cost. As you see the last of our migratory birds leaving over the next few weeks, wish them well on their way.
Also, look out for a more in-depth post by Emily Brodsky on Raptor Migration in the next few days!
Note: For excellent maps of where birds spend their summers and winters, see the Cornell Lab of Ornithology’s website All About Birds.
By Danielle Owczarski
Crickets sound their high-pitched hum, blaring sirens swell and shrink, sweat percolates in overlapping areas, distant music floats through the moonlit breeze, insomnia returns, a kingfisher chatters along the lake shore, a main sail flaps in the breeze – all signifying the shift to summer in Burlington. Spring has its moments with its ephemeral blooms, but with summer, we shed the last layers of clothing. White skin peeks out no longer shy, soon many shades darker and prominently displayed. We relish the summer months without the taunting of spring’s undulating meteorological moods. Like our seasonal feathered friends, we break out into bold colors and partake in the ritualistic dance of the Burlington Jazz Festival and music on the waterfront. The neighborhood druids welcome the summer solstice by gathering around the Earth Clock in Oakledge Park, drumming in the sunlight’s energy.
Midsummer festivals, boldly celebrated in pre-Christian times and still today in many cultures under an altered guise, take place around the solstice. The Oxford English Dictionary states that summer has its origins in Old English as sumor, sumere, and somera among other variations first recognized in text c. 825, referring to its role as the warmest season of the year. And while summer more accurately applies to the astronomical solstice then to the actual beginning of the seasonal and climatic change, it is understood as a time of fertility, growth, and warmth. Bonfires and heavy drinking are the most common signifiers of midsummer revelries throughout the world, the celebration linked to the birth of John the Baptist, born six months prior to Jesus. However, stripped of its religious shroud, in the silence and beauty of the early morning, summer is the celebration of energy transformed into life.
Despite the simplicity of its title, summer is dynamic, generating an ever-changing understory and flow of biotic change. Those of us who work outside during this time of year follow the influx of hatching insects good and bad. Appearing first are the black flies, followed by the deer flies and mosquitoes. While the former two usually abide by shorter seasons, the mosquitoes continue hatching throughout the late summer months. Overshadowed by the annoying, small flying insects are those who act as predators keeping them at bay.
Dragonflies, unbeknownst to some, live most of their lives (up to four years) as armored nymphs in calm aquatic environments. The warm sun of early summer heats the waters, enticing the mature nymphs to the surface where they crawl out and clasp themselves to tall grasses, wood, and stone. Here they begin their hatch. Attached to a cattail leaf above the water, the nymph’s exoskeleton begins to dry and crack along the back where the dragonfly emerges, compressed and translucent, expanding into a world of bug feasts, avian maneuvers, sex, and egg laying. Their terrestrial phase occurs no longer than two months causing their numbers to dwindle by late summer.
Those of us working inside this time of year suffer through the mocking rays of light filtering through paned glass windows. The vigor of those coming in from outside tickles the nerves and draws conscious thought away from tasks and into daydreams of lake breezes on bare skin, lush winding hiking trails, and the transforming hues of clouds low on the horizon. For most of us trying to take advantage of the summer day, a strange phenomenon occurs, while the length of the day in relation to sunlight increases, time seems to move more quickly. Weekends fill with social obligations, and the list of things to do and places to visit become too numerous to accomplish. Summer spurs the endless chase of the elusive present moment.
In nature, as the season progresses, the once electrifying greens of spring begin to dull. Before we know it, tomatoes are ripening into deep reds and purples, and the goldenrods and asters are blooming. In town, the college students are moving into their dorms and young children board the yellow bus while we wait patiently in traffic. Some welcome the change with anticipation of harvest festivals, cider donuts, and corn mazes, while others feel depressed by the notion of winter’s encroaching darkness. Despite our resistance, the mayfly, stonefly, and caddisfly, each year during this time, hatch, lay their eggs, and die. The brook trout rise to eat, and a small red maple leaf flutters, dropping slowly to the water’s surface.