My wife has a keen eye for the little things. We were walking on our local bike path the other day and she spied a beetle on the pavement. She is always helping critters cross the greenway. Turns out this beetle wasn’t so little. At up to an inch and three-quarters (4.5 centimeters) long, this Eastern Eyed Click Beetle (Alaus oculatus) is one of the larger beetles in Connecticut. Also called Eyed Elater, it is a member of the Elateridae, the click beetle family.

What a neat-looking insect! It has two large “eyes” on its pronotum (a plate on the upper surface of the thorax), markings that evolved to startle or confuse potential predators.

The adult Eastern Eyed Click Beetle has a long, thin body. Along with its large fake eyes and black-and-white, mottled coloring, you can identify it by its behavior. This beetle often “plays dead” when picked up. Try turning a click beetle onto its back (please return it to where you found it afterward). By quickly snapping a spine-like structure into a groove on the underside of its thorax, it will flip suddenly as much as 6 inches (about 15 centimeters) into the air. It usually lands right-side up. This can startle a predator and also help the beetle escape. The snap is accompanied by an audible click that gives the beetle its name.

Eastern Eyed Click Beetle larvae are 2.5 inches (6.35 centimeters) long, wormlike, shiny, and segmented. Called wireworms, they have six small legs and are brownish and darker brown near the head. They look a bit like the mealworms sold at bait and pet shops, but have large mandibles.

Many click beetle larvae are herbivores and agricultural pests that damage wheat, corn, and potato seedlings. The larva of the Eastern Eyed Click Beetle, however, is a voracious predator. It lives in decaying wood and feeds on the larvae of flies, moths, and especially on those of the insect family Cerambycidae, the longhorn beetles. In one study, click Eastern Eyed Click Beetle larvae were observed to eat over 200 cerambycid larvae each (see Insect Enemies of Eastern Forests by F.C. Craighead).

The Eastern Eyed Click Beetle spends two to five years as a larva, but live for only a few weeks as an adult. Adults don’t eat much, but have been seen feeding on nectar and plant juices. These beetles are found in hardwood forests that have lots of rotting logs, especially cherry, apple, and oak.

A fascinating, uncommon insect, the Eastern Eyed Click Beetle is worth keeping an eye out for. Enjoy them whenever you are lucky enough to see one.

Spring has sprung in full form and many of Connecticut’s ephemeral wildflowers have now finished their frenzy of flowering before being locked in shade by newly emerging, bright green leaves of trees. A few weeks ago I was fortunate to see one of the early spring butterflies in my yard: an adult Red Admiral (Vanessa atalanta).

I thought that the beginning of April was quite early for this butterfly to be flying around. Daytime temperatures were in the mid-50s (13 °C ) and in the 40s (7 °C) at night. Why was it out and about? Without much in bloom yet what flowers were providing nectar for it?

The Red Admiral adult I saw may have spent the winter in hibernation in a bark crevice or other tight cavity. Did it stay in the brush pile at the edge of my property? Unlike the Mourning Cloak (Nymphalis antiopa), Red Admirals usually can’t survive really cold winters.

In the fall, many Red Admirals migrate south, as far as southern Texas. In early April we had two strong and very stormy weather systems that transported warm, moist air from the Gulf of Mexico into our area. Remember those freakish record-breaking few days in the high 80s and 90s (25 °C to 35 °C)? It’s possible my Red Admiral arrived then.

This butterfly has evolved to survive early spring’s cool temperatures. The adult’s black background helps absorb heat. It also likes to feed on the sap running in trees, so doesn’t depend on nectar from flowers. They will occasionally feed on nectar later in the season. Red Admirals also gets minerals from bird droppings and dead animals.

Red Admirals have a worldwide distribution. They are found in the temperate regions of North Africa, North and Central America, Europe, Asia, Hawaii, and the Caribbean. Adults have a wingspan from 1.75 to 3 inches (4.5 to 7.6 cm). They are mostly black with broad orange (not red) bands on top of the fore- and hindwings. The upper forewings have white dots at the wingtips.

The Red Admiral was not named after a British naval commander, but rather by 18th-century naturalists. Its name is a corruption of the word “admirable.” This butterfly was first described by Carl Linnaeus in 1758.

The best way to attract Red Admirals to your yard is to plant one of its host plants, the plant where females choose to lay their eggs to provide food for the larvae, or caterpillars. The primary host plant for the Red Admiral is Stinging Nettle (Urtica dioica). Plant it in a shady spot with rich soil, but out of the way. Stinging Nettle has fine hairs on its leaves and stems that contain irritating chemicals. These are released when the plant comes in contact with skin. The hairs are normally very painful to the touch.

Stinging Nettle, however, does make a very healthy cooked green. Cook it like spinach, boiled in salted water for 45 seconds to a minute. According to an article published in the National Institutes of Health’s National Library of Medicine, its leaves have abundant fiber, minerals, vitamins, and antioxidant compounds like polyphenols and carotenoids.

If the idea of planting Stinging Nettle doesn’t suit you, try False Nettle (Boehmeria cylindrica), a related species that doesn’t have stinging hairs. It grows in the same rich, moist shady locations. False Nettle is hard to find, but can sometimes be discovered for sale online.

So, grow some larval food plants and the butterflies will come.

---

You might think during these dreary, gray winter days that nature is dormant and there is not much to see. But here in Connecticut, and throughout much of the country, hawk-watching is easy. Hard to believe, but one of the best places to see hawks in winter is from your car. Please, keep your eyes on the road, but next time you are traveling along a highway, you may well glimpse out of the corner of your eye a large, bulky brown bird perched on a light pole or dead tree. Nine times out of ten, you’ve seen a Red-tailed Hawk (Buteo jamaicensis).

Although redtails can differ in color, one of the easiest ways to tell them from other hawks is by their large size and “belly band.” This is typically a white upper chest with a line of darker feathers on the bird’s belly that starts half-way down. This can be seen from quite a distance. Adults have a rust tail easy to see in flight. Another related winter resident, the Red-shouldered Hawk (Buteo lineatus), is smaller, with rusty red patches on its shoulders, a reddish belly, and a banded black-and-white tail. Redtails have broader wings and fly with slower wing beats compared with the Red-shouldered Hawk’s more “nervous” flight pattern and faster flight. Also look for the clear “windows” at the base of the primary wing feathers in a flying Red-shouldered Hawk.

It is easier to spot Red-tailed Hawks in the winter than in the summer, because there are more of them. Redtails are partial migrants. They typically migrate to southern areas to find more food and better weather conditions. But some birds stay here year-round, so in winter we see both migrants and permanent residents.

A Red-tailed Hawk often hunts from a perch. Typically, more than 80% of its diet consists of rodents such as voles, mice, and squirrels. It will also eat rabbits and birds—including the European Starling (Sturnus vulgaris) and Red-winged Blackbird (Agelaius phoeniceus)—as well as snakes and carrion.

Redtails are quite adaptable. They are seen in open habitats: forest edges, fields and pastures, parks, and even in cities. You might have heard of Pale Male, who hatched in 1990 in New York City and helped establish a line of urban-dwelling hawks there. Ten years ago a pair of Red-tailed Hawks built a nest downtown near the New Haven Green in Connecticut, in the arms of a statue on the New Haven County Courthouse! Urban birds live quite well on Eastern Gray Squirrels (Sciurus carolinensis), Norway Rats (Rattus norvegicus), and other rodents.

The Red-tailed Hawk is in a group of hawks called buteos, which have wide, rounded wings and a fan-shaped tail for soaring. With these the birds catch warm, spiraling air currents called thermals that help them rise and then soar to other places. The redtail is the largest buteo in the eastern United States. The Ferruginous Hawk (Buteo regalis) in the western US is larger. Redtails are one of the few birds that you’ll see “kiting,” or soaring motionless in the wind.

Sometimes while a redtail is soaring you’ll hear its raspy, two to three second keeeer! scream. Hollywood has taken notice. Ironically, our mighty national bird, the Bald Eagle (Haliaeetus leucocephalus), makes short, weak little chirps. When you hear the screech of a flying eagle in a movie, it’s actually the redtail’s call, much to the dismay of many a naturalist. My wife gets frustrated with me when I keep mentioning wrong bird songs and other inaccuracies about nature in the cinema.

Redtails will be courting soon, which is in March in Connecticut. In courtship, flying pairs have been known to lock talons and dramatically spiral downward. They will make a nest of sticks usually 40 to 75 feet (about 12 to 23 meters) above ground in a large tree that provides a clear flight path. They’ll produce one to five eggs in late March and early April that hatch about a month later. The young birds will fledge in 42 to 46 days. Adults usually mate for life and if one mate dies the other finds a new partner. Redtails can live 10 to 20 years.

Predators generally, and hawks in particular, are often maligned and misunderstood. As predatory birds that hunt during the day when free-range chickens are out and about, hawks are not always appreciated by farmers for doing what comes naturally. But like all predators, they have a critical role to play. At this time of year, when it seems there is little to see, it’s nice to know there’s plenty of great hawk-watching to be had.

On this Winter Solstice, the forests are now colored in various shades of tan and brown here in southern Connecticut. But here and there are patches of green. Whether they signify rebirth, a new life, immortality, or peace, plants that are still green have played an important role in almost every holiday celebration, particularly during the winter.

Plants that remain green in winter can still photosynthesize using the sun’s light plus water to produce sugars to “feed” themselves.

How are these plants able to stay green and keep from freezing? Cold stress is just as lethal to plants as heat stress. When water inside the cells freezes, it expands, causing the cell membranes to burst and the cells (and plant) to die.

Many plants in winter respond to colder temperatures by accumulating sugars and moving them to the leaves. Those sugars lower the temperature at which ice forms—like putting salt on the roads.

Another adaptation plants have evolved for protection in winter is to make proteins. This helps to stabilize cell membranes and keeps them from bursting.

We’ve had several nights below freezing and yet the Pansies (Viola spp.) in my window box are still green and in flower! I think, though, it is just a matter of time before freezes will kill the Pansies, so I’ll soon be moving them to the porch.

Look for evergreen ferns on your next winter hike. I say evergreen, but no plant is truly evergreen. Plant leaves and fronds eventually die and are replaced. Marginal Wood Fern (Dryopteris marginalis) and Christmas Fern (Polystichum acrosticoides) are two ferns that are easy to find now and throughout the winter. They are often seen growing near one another.

Marginal Wood Fern is a light blue-green with broad, twice-compound leaf blades (divided into leaflets that are further divided into more leaflets). The Christmas Fern is named because its dark, leathery leaves are green at holiday time, and because each of its leaflets are lobed like a Christmas stocking.

Patches of these ferns provide winter cover near the ground for songbirds. Some bird species use parts of the fern’s scale-like hairs to build nests come spring.

Both of these plants feel rather waxy to the touch—yet another great adaptation for protecting leaves in the cold. Many coniferous, or cone-bearing, trees have waxy leaves or needles too. Coniferous trees and native, broad-leaved evergreens such as Mountain Laurel (Kalmia latifolia) and Inkberry Holly (Ilex glabra) are very important for birds and other wildlife in the winter. These plants provide shelter from harsh winter winds and protection from precipitation.

If you see what looks like miniature pine trees growing in a line on the forest floor in winter, you’ve found one of the clubmoss species, an ancient line of fern relatives in the genus Lycopodium, Dendrolycopodium, Diphastiastrum, or Huperzia. Nicknamed ground pine or running pine, and only a few inches off the ground, the ancestors of these plants during the Jurassic Period were more than 100 feet (30.5 meters) tall! Please don’t cut club mosses for holiday wreaths. The plants grow very slowly and local patches can be wiped out by collecting.

Even though I know we’re in for more frigid temperatures, I look forward to the increasing light of longer days from here on. The winter’s greenery invites you to look forward to spring.

Wishing you peace and a healthy, prosperous New Year.

It’s mid-October. The Sugar Maples (Acer saccharum) are on fire this year, with deep oranges and ruby reds. You might think that most of our migrant birds have all gone by now, but that’s not true. Among others, I have been seeing flocks of Yellow-rumped Warblers (Setophaga coronata) feeding on the berries of Spicebush (Lindera benzoin). They are heading south to winter in the southeastern United States. Dark-eyed Juncos (Junco hyemalis) and White-throated Sparrows (Zonotrichia albicollis), which spent the spring and summer in northern New England and Canada, are now arriving to spend their winter here in Connecticut.

What you might not expect to see now are Common Green Darner dragonflies (Anax junius). They are passing through too. Most people know that Monarch butterflies (Danaus plexippus) migrate south to spend the winter in the Oyamel Fir forests (Abies religiosa) in Mexico. But some dragonflies migrate too. In fact, Green Darners are one of at least 16 migratory dragonfly species in North America.

The Common Green Darner is a large dragonfly that grows to be 2.7 to 3.3 inches (6.8 to 8.4 centimeters) long, with a wingspan of 3.5 to 4.5 inches (9 to 11.5 centimeters). The male has a pale green head and thorax and a blue abdomen. The abdomen of the female and immature darners is green, brownish, or reddish. Darners get their name from their long, thin abdomens, which resemble a darning needle. Green Darners are one of the most common dragonflies and are found throughout the eastern United States and on the West Coast.

Dragonflies are skilled aerial predators. With their four wings they can maneuver quickly in mid-flight to catch a variety of flying insects. The immature nymphs are aquatic and feed on other small insects, and even small fish and tadpoles.

Unlike flocks of birds or a kaleidoscope of butterflies (yes, that’s what a group of butterflies is called), Green Darners often go unnoticed. They are some of the most abundant dragonflies on the continent—yet few people notice this mass migration. They too can swarm in large groups, particularly along the New England coast.

In a study published in Biology Letters in 2018, researchers from the Vermont Center for Ecostudies, the University of Maryland, and the Smithsonian Conservation Biology Institute described how the Green Darner completes its migration. They learned that most individuals traveled an average of 373 miles (600 kilometers) and that some migrated more than 1,553 miles (2,500 kilometers)!

The Common Green Darner has a multi-generational life cycle. The first generation hatches in the southern United States from February to May, migrates north, lays eggs, and then dies. The second generation emerges that summer in the north, migrates south, lays eggs, and then it dies. The third generation emerges there around November. This generation doesn’t migrate but will live through the winter in the South, lay eggs, and die. The cycle then repeats.

Understanding this migration gives scientists more information about the life cycles and ecology of insects. This is particularly important because of their declining populations and their role as a valuable food in ecosystems.

The researchers were able to track Green Darner migrations with a bit a chemical sleuthing. For two years, they captured dragonflies throughout eastern North America with the help of other biologists and citizen scientists. They also got permission to take samples from specimens in museums from Canada to the Caribbean. In both groups they looked for a hydrogen isotope, sampling more than 800 dragonfly wings. Most hydrogen atoms have a single proton, but a small percentage have a proton and neutron. This isotope is called deuterium.

The amount of deuterium in rainwater varies in North America along a north-south gradient. Because dragonflies are born and grow as nymphs in water, they take in deuterium in their bodies. The isotope is incorporated into the chitin in their adult wings. Measuring this deuterium told the researchers where each dragonfly was born.

The next time you see Common Green Darners in the fall, wish them a safe journey.

---

In traditional Irish music, there is a tune that goes by the title “Touch Me If You Dare.” The same can be said for the Spotted Touch-Me-Not (Impatiens capensis). This plant gets its common name from its fruit, which when ripe pops and releases its seeds. It’s fun to get those mature, bulging fruits, called capsules, to “explode.” Hold the ripe capsule on both ends between your thumb and forefinger and press slightly inward. The five valves inside the fruit will coil back and eject the seeds up to 5 feet (1.5 meters) away! This is called explosive dehiscence or ballochory. Sometimes all you have to do is touch the fruit while walking by. It’s a good adaptation that gets seeds away from the parent plant and possibly to better soil.

Spotted Touch-Me-Not’s species name, capensis, is a botanical mistake. The plant was named by Nicolaas Meerburgh, a botanist in the 1700s at the Hortus Botanicus in Leiden, Netherlands. He thought Spotted Touch-Me-Not came from the Cape of Good Hope in South Africa, and not North America.

Another common name for the plant is Jewelweed. There are several reasons for this name. The bright, showy, 1.25-inch (3.2-centimeter) trumpet-shaped orange flowers look like jewels one might wear as earrings. Or because beads of rain or dew on its leaves shine like jewels in the sun. Others say it is because microscopic hairs on the leaves (particularly the undersides) trap air and give them a silvery look when under water. Dip a leaf into water to see it shimmer and lift it back out. It will come out dry!

Yet another possibility for the name is the color of the seed. Peel the seed coat of a mature brown seed. Inside it is a bright, robin’s egg blue.

Jewelweed is an annual. It can really spread through your garden beds if you have rich, moist soil, but it is easy to pull. I leave lots of it in my yard at this time of year as its flowers are one of the primary nectar sources for the migrating Ruby-throated Hummingbird (Archilochus colubris). This year, with drought in our area, I am concerned about the birds getting enough nectar to refuel during migration since plants and flowers are drying up.

Jewelweed might have a survival trick. Besides the showy, open chasmogamous flowers you usually see, which require cross-pollination, Jewelweed can also have small buds with unopened flowers on the same plant. These are self-pollinating, just like Violets (Viola spp.). These closed cleistogamous flowers can help the plant spread under stressful conditions, like drought.

The flower’s five petals and three sepals are fused. One of the sepals forms the small nectar spur at the back of the flower. This is usually twisted around in a curly-Q back toward the front of the flower. This twisted spur is thought to have played a role in plant–pollinator co-evolution. Hummingbirds are believed to be the most efficient pollinator for Jewelweed, although I have also seen bumble bees (Bombus spp.), and wasps pollinating Jewelweed.

Pale Jewelweed, or Pale Touch-Me-Not (Impatiens pallida), is a similar species of Touch-Me-Not that is more common in western New England. Like its cousin, it grows in moist areas, along streambanks and similar habitats. Pale Jewelweed’s nectar spur is bent downward at 90 degrees. This plant is pollinated mostly by bumble bees and other insects rather than hummers.

Jewelweed has a long history of medicinal uses. Indigenous peoples made a topical salve with it. You may have heard that Jewelweed is an antidote for contact with Poison Ivy (Toxicodendron radicans). This has been argued for years. A controlled trial for the U.S. National Institutes of Health found the crushed stems and juice of Jewelweed were indeed effective for preventing the Poison Ivy rash after contact. The soapy compounds called saponins in Jewelweed might be why, yet washing with soap and water gave better results. But, if you are in the woods without access to soap and water, Jewelweed is a good solution.

Touch-Me-Not has evolved some fascinating adaptations to survive. Go ahead and dare to touch a seed pod today.

Thousands are flying through the night now. As the dog days of summer hit Connecticut, complete with heat waves full of hot, humid weather, drought, and nights filled with the raucous, sharp, three- or four-syllabled buzzing of the Common Katydid (Pterophylla camellifolia), you might not usually think of birds flying south. But they are.

This is the peak “fall” migration for many shorebirds, who either nested here or are just passing through on their way to wintering grounds in the southern United States, and in Central and South America.

You’ll often see quite a few species in large numbers stop to rest and re-fuel along the coast. I recently checked the CTBirds email list server sponsored by the Connecticut Ornithological Association. Someone had spotted more than 1,000 Common Terns (Sterna hirundo) feeding and resting at Stratford Point in Stratford, Connecticut.

Other places in the state to see migrating shorebirds include Hammonasset Beach State Park in Madison, Connecticut Audubon Society Coastal Center at Milford Point, Bluff Point State Park and Coastal Reserve in Groton, and more. Check out the book Birding in Connecticut (Wesleyan University Press, Garnet Books, 2018) by Frank Gallo for what species to see where and when.

Most birds migrate during the night. There are several possible reasons for this. These birds are diurnal feeders and it is easier to find food during the day. There are also fewer predators at night. And it is easier for birds to fly at night when the cooler, denser air helps them generate more lift. Birds use the stars to navigate on their journey south. They also use magnetoreception to sense Earth’s magnetic field, which guides them on when and where to stop.

The Cornell Laboratory of Ornithology has a very informative site, the BirdCast Migration Dashboard, that uses radar to show the approximate number and type of birds that migrated the previous night. It gives the direction of travel, general altitude, and speed of the birds. On August 11, 2022, around 202,600 birds crossed through Connecticut. At 1:50 am, the migration peaked at 134,100 birds traveling at an average speed of 26 miles per hour (about 42 kilometers per hour) at a height of 1,500 feet (about 457 meters)!

The shorebirds passing through that night included Least Sandpipers (Calidris minutilla), Short-billed Dowitchers (Limnodromus griseus), Long-billed Dowitchers (Limnodromus scolopaceus), Semipalmated Sandpipers (Calidris pusilla), and Semipalmated Plovers (Charadrius semipalmatus).

The endurance these shorebirds is truly remarkable. Biologists think that the eastern population of the Least Sandpiper, after nesting on the tundra of northern Canada, travels down the Gulf of St. Lawrence and the eastern coast of New England before flying non-stop 1,800 to 2,500 miles (about 550 to 760 kilometers) to northern South America! This bird weighs only an ounce (28 grams) and is only 5 to 6 inches (13 to 15 centimeters) long. It is the smallest shorebird in the world.

Like a jumbo jet, to make such a long, non-stop trip requires lots of fuel. Shorebirds fatten up before their flight. Some species double their weight before leaving. They shed unneeded weight by reducing the size of their leg muscles and digestive system, but gain it back when they arrive. The flight muscles also get larger and their blood thickens, allowing these birds to pump more oxygen through their body.

If you have binoculars, a spotting scope, or a telescope, and it is a night with a full moon or close to one, a fun activity would be to go out to watch the moon for a while. You’ll often see the silhouettes of flocks of birds flying across the moon’s face. The next full moons during this year’s migration will be on September 10 and October 9. I’ll make it a point to stay awake and catch this wonderful autumnal sight—and maybe you can too.

Have you heard the joke that the state bird of New Jersey is dead. Being from the Garden State, I sometimes tell that one. Actually, the New Jersey state bird is the American Goldfinch (Spinus tristis), a colorful, permanent resident native to a large part of the US.

In mid-summer, when the nesting season begins to wind down for most Connecticut birds, the American Goldfinch is just getting going. It is the last of our resident birds to nest, during July and August. Nest building is timed for when thistles (Cirsium spp.) go to seed.

The female goldfinch builds a cup-shaped nest in a shrub or small tree, often out in the open rather than deep in the forest. She lines the nest with soft thistle down, sometimes so much that it can be hard to see the eggs! She chooses two or three forked branches to support the nest, usually 4 to 20 feet (about 1 to 6 meters) off the ground. You might be able to get goldfinches to nest in your yard by planting trees and shrubs, particularly if they are at the edge of a woodland. Fruit trees, Buttonbush (Cephalanthus occidentalis), Black Elderberry (Sambucus nigra), Flowering Dogwood (Benthamidia florida), and hawthorns (Crataegus spp.) are popular nest sites.

American Goldfinches are very social birds. Unlike most birds, they will not set up nesting territories or try to scare away a goldfinch flock that comes close to a nest. The female lays from 4 to 7 light blue eggs that she incubates for 12 to 14 days. The male will feed her during this time. When the eggs hatch, she will be the primary caregiver. But as the chicks grow, the male takes over more of the feeding. A female will sometimes start another brood while the male is feeding the fledglings. After 10 to 15 days the young leave the nest. They will continue to be fed nearby for a few weeks afterward.

Recently, I saw several male goldfinches in quite acrobatic positions, even hanging upside down, while eating thistle seeds. They are not picky about what kind of thistle they eat, whether native species like Field Thistle (Cirsium discolor), Swamp Thistle (Cirsium muticum), and Pasture Thistle (Cirsium pumilum), or non-native Tall Thistle (Cirsium altissima), Creeping Thistle (Cirsium arvense), and the invasive Common or Bull Thistle (Cirsium vulgare). While thistles might be their favorite food, goldfinches will eat other types of seeds too, including purple coneflower (Echinacea spp.), bee balm (Monarda spp.), asters (Symphyotrichum spp. and other genera), Dandelion (Taraxacum officinale), and sunflowers (Helianthus spp.). They also eat tree buds, maple tree (Acer spp.) sap, raspberries (Rubus spp.), and more.

Although most passerines (the perching birds) feed their young insects, like caterpillars and other easily munchable packets of protein and fats, goldfinches are mostly vegetarian. Parents will regurgitate thistle and other seeds for their chicks, and sometimes include insects like aphids. Vegetarian goldfinches are a problem for the Brown-headed Cowbird (Molothrus ater), which sometimes lay its eggs in goldfinch nests. Cowbird chicks need a diet of insects and so usually die within two or three days of hatching.

I love to listen to a flock of goldfinches singing in my yard. The male’s song is a several-second series of twills and warbles that is very canary-like. The flight pattern of both males and females is easy to spot—they swoop up and down as they fly. Both males and females make a “po-ta-to-chip” or “per-chicory” call when they fly.

Did you know that a flock of goldfinches is called a charm? These spunky, acrobatic, social birds with canary-like songs definitely are charming, and a joy to have around.

If you could go back 500 million years in northwestern Connecticut, you would be standing at the eastern edge of the Proto-North American continent and along the shoreline of a tropical ocean. What a difference!

Today the diversity of plants in this area is astonishing, largely because of the bedrock below. When most of us look at plants, we seldom think about what is under them or how it affects what grows. Indeed, many gardeners neglect even to test the soil that nurtures their flowers and vegetables. What is under the ground, however, plays a vital role in what can grow above the ground.

Back to that tropical sea. How do scientists know that’s what was once there? Geologists say that “the present is the key to the past.” Rocks today are clues to how Earth looked long ago. To determine the geology of Earth’s ancient surface (called paleogeography) and how continents moved through time, geologists study the rock and fossil records. They use techniques like paleomagnetism to examine ancient volcanoes, and more.

The Proto-North American continent, called Laurentia, was then on the equator, hence the tropical climate and life. The ancient, tropical sea floor was different from the tropical coral reefs we know today. When this ancient life died and settled onto sediments on the sea floor, over time it was compressed into limestone, which is primarily made of calcium carbonate. At the time of the ancient sea floor, Laurentia collided with the southern continent Gondwana, closing the ancient Iapetus Ocean. The limestone was changed, through heat and pressure, into the metamorphic rock called marble.

Because Stockbridge Marble is limestone changed through metamorphism, it might be hard to distinguish what organisms helped form it, but clues might be nearby. To the west, in Saratoga, New York, stromatolites have been found in Hoyt Limestone that dates to about the same time, so they might have been in the marble too. Stromatolites are layers of microorganisms that use photosynthesis, like cyanobacteria. Stromatolite mounds are among the oldest fossils on the planet, over 2 billion years old. These mounds were a primary contributor of oxygen (a by-product of photosynthesis) to the planet’s early atmosphere!

Recently, I was privileged to be able to collect samples of Stockbridge Marble, for the Peabody Museum’s geology classes, from one of northwestern Connecticut’s quarries, situated in the landscape known as the “Marble Valley.” It’s rather amazing to think that the piece of marble you are holding was once part of an ancient tropical ocean.

Some of these quarries have been in operation since the 1700s, when they produced stone used in ironmaking to remove impurities. Local maps of the area have place names like Lime Kiln Road from that period. Today the quarries extract marble mostly as chips for aggregate and powder that farmers add to their fields to “sweeten” the soil (make acidic soil more alkaline).

Immediately to the west of the Marble Valley are the hills of the Taconic Range. During that time of colliding continental plates, when the marble was formed, the mountain building process thrust peaks more than 20,000 feet (6 kilometers) into the air. These ancient rocks, now eroded, are composed mainly of schist and gneiss. The gneiss found here is Connecticut’s oldest rock, formed 1.2 billion years ago!

Because of this complex geology—high pH (alkaline) calcareous soils in the Marble Valley and acidic soils in the nearby hills—this area has the highest plant diversity in the state. The area also includes one of Connecticut’s most imperiled ecosystems—calcareous fens. These are places where springs trickle up through marble into a peat wetland. They contain threatened and endangered plants found nowhere else. This unique and fragile ecosystem is threatened by the encroachment of invasive plants such as Phragmites (Phragmites australis), which can overrun and completely change habitats. It will be important to manage these habitats and the beautiful hills around them, so that generations to come can enjoy this remarkable geology and its ecosystem. Next time you get a hankering for the tropics, give thought to that bit of ancient tropical ocean you might have nearby.