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.

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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.

The catkins of the shrub Pussy Willow (Salix discolor) flower in early April along the edges of wetlands and wet meadows in southern Connecticut. On a damp, early spring day these flowers on bare stems light up the landscape like a collection of bright stars in a dark sky.

The fuzzy, silvery catkins look like the tip of a cat’s tail. The name is from the Dutch word katteken (“kitten”). A folktale tells the story of how the Pussy Willow got its catkins. One day, down by a river, when her kittens fell in, the mother cat’s cries were answered by a willow tree that bent down and rescued the kittens with its branches.

The flower’s hairs keep it warm during cold snaps in late winter and early spring. Catkins have no petals, nor are they fragrant. A catkin is actually an inflorescence, a cluster of individual flowers. Pussy Willow shrubs are dioecious (“separate houses”), with male and female flowers on separate plants.

Native plants in our gardens can be an ecosystem for the wildlife that evolved with them. While you are examining the Pussy Willow’s unique flowers, you will probably see some movement nearby. These shrubs are a five-star restaurant for early insects. Many native bees, including mining bees (Andrena spp.), mason bees (Osmia spp.), emerging queen bumblebees (Bombus spp.), the Unequal Cellophane Bee (Colletes inaequalis), the non-native European Honey Bee (Apis mellifera), and early butterflies such as the Spring Azure (Celastrina ladon) or Mourning Cloak (Nymphalis antiopa) all seek the flowers’ copious pollen and nectar. The Xerces Society for Invertebrate Conservation calls the plant “a vital food source for hungry pollinators” and a “must-have for the pollinator garden.”

Entomologist Heather Holm, author of Bees: An Identification and Native Plant Forage Guide, stresses the importance of planting native shrubs and trees in our yards. She calls these gardens “the meadows of the sky,” because they provide much more food for pollinators than the herbaceous plants in a meadow. Pussy Willows, with multiple stems that can reach up to 20 feet (6 meters), are loaded with flowers—a true pollinator powerhouse.

Not only is the Pussy Willow a source of nectar and pollen, but its leaves are larval food for up to 18 species of butterflies and moths in our region, including the Mourning Cloak, Eastern Tiger Swallowtail (Papilio glaucus), Viceroy (Limenitis archippus, a Monarch mimic), and beautiful giant silk moths such as the Promethea (Callosamia promethea), Polyphemus (Antheraea polyphemus), and Io Moth (Automeris io).

Pussy Willows also provide thick cover for nesting birds, such as the Alder Flycatcher (Empidonax alnorum),Willow Flycatcher (Empidonax trailii), Gray Catbird (Dumetella carolinensis), Yellow Warbler (Setophaga petechia), and American Goldfinch (Spinus tristis).

When you look for Pussy Willows in a local nursery, confirm that it has the true species, Salix discolor. The European and Asian species often for sale will not provide larval food for native butterflies and moths.

Pussy Willows thrive in moist areas with part to full sun, but are also tolerant of regular soils once established. They are easy to propagate. One way is to root a 6- to 12-inch (15- to 30-centimeter) twig in water. Root it in April and, once roots form after a few weeks, plant it in May. Keep the plant well-watered until established and water at least once a week for the first year.

Pussy Willow twigs have a high concentration of the natural plant hormone indolebutyric acid (IBA). This hormone stimulates root growth. To make a homemade solution that will help cuttings to root faster, soak the cut tips of willow branches in water and then use this water to root other plant cuttings.

Easy to grow and propagate, and a key pollinator and larval food plant, Pussy Willows truly are the cat’s meow.

I recently heard a raspy “feee-beee,” one of the sure sounds of spring—it was an Eastern Phoebe (Sayornis phoebe) singing and just back from its wintering grounds in the southeastern United States.

The Eastern Phoebe is a member of the Tyrant Flycatcher family, the Tyrannidae. It has a grayish back with a darker gray head and whitish belly. The best way to tell it apart from the similar Eastern Wood Pewee (Contopus virens) is by its behavior. Phoebes constantly wag their tails up and down.

I have often wondered why flycatchers that hunt flying insects in mid-air return so early in the year, in late winter and early spring. The weather is so fickle then, often changing from sunny 60°F (15°C) days to blustery storms with ice and snow. How do they survive when there aren’t many flying insects around?

A clue might be where they like to nest. These birds once only nested in places like the natural shelves created by rocky crevices in ravines. Humans-created ledges, such as the eaves of barns and other buildings, as well as under bridges, are perfect nesting places for them. These are also precisely where insects and spiders go to get out of the wind and weather. Phoebes take advantage of this by gleaning such prey from the beams and walls. When the weather warms, the birds hunt in sunnier locations and when insects are flying. Flycatchers, including the Eastern Phoebe, are known for “hawking” or “sallying”—flying out suddenly from a perch, grabbing a flying insect, then returning to the same place. Their prey includes beetles, flies, grasshoppers, bees, and wasps.

Eastern Phoebes, because they often nest along forest edges, are particularly vulnerable to nest predation by the Brown-headed Cowbird (Molothrus ater), a nest brood parasite. Once a female cowbird spots a phoebe nest with eggs, she’ll lay her own egg in it. The phoebe parents won’t recognize this egg as different from their own. When the eggs hatch, the much larger cowbird chick will get more food, decreasing the phoebe chicks’ chances of successfully fledging.

Despite this, Eastern Phoebe populations are stable now, which might have to do with their willingness to nest on human structures. They also adapt by feeding on fruit from plants such as Pokeweed (Phytolacca americana), Wild Grape (Vitis spp.), Virginia Creeper (Parthenocissus quincefolia), Poison Ivy (Toxicodendron radicans), and more, particularly during the winter months and when first returning north.

Phoebe pairs often return to the same nest every year and just refurbish it. This was discovered by noted naturalist and painter John James Audubon. In 1803, Audubon put silver thread on the legs of a brood of chicks near his home in Pennsylvania. The following year he captured two of these chicks that had returned. This is the first documented case of a banded bird returning. Banding today is an important way for scientists to learn more about bird life histories and migratory routes. Perhaps the phoebes you see in your neighborhood are old friends that come back year after year.

As late winter turns toward spring, local birds will soon begin to look for mates and nest sites. Along with birds that make their nests on branches or in the crotch of a tree, there are many species that nest in cavities. But finding the right hole in a tree is not always easy. Competition for these cavities is keen. Many areas may just not have enough holes in suitable habitat. Smaller birds such as the Eastern Bluebird (Sialia sialis), Tree Swallow (Tachycineta bicolor), Black-capped Chickadee (Poecile atricapillus), Tufted Titmouse (Baeolophus bicolor), House Wren (Troglodytes aedon), and others often depend on woodpeckers to create holes for them.

You can help birds that nest in cavities by putting a nest box in your yard or a nearby preserve. Large yards, pastures, orchards, fields, cemeteries, and other empty spaces are all good places for a nest box for Eastern Bluebirds. Because bluebirds and most other birds feed almost exclusively on insects during the nesting season, it is important not to place a box where insecticides and herbicides are used. You may read that nest boxes should be up by the end of March, but you have some flexibility because many species have multiple broods.

In the past, bluebirds often nested in the holes of wooden fence posts in agricultural areas. Loss of rural farmland and orchard habitat and the replacement of wooden posts with plastic and metal have contributed to population losses. Another major factor in bluebird decline was the introduction of the non-native European Starling (Sturnus vulgaris) and House Sparrow (Passer domesticus). Both are very aggressive cavity nesters and will kill bluebirds. Starlings can be kept out of bluebird nest boxes that have the properly sized 1.5 inch (4 centimeter) diameter entrance hole. However, the smaller hole won’t deter House Sparrows from trying to use the box. You’ll need to be vigilant and pull out any nesting material from House Sparrows. House Sparrows also like perches, so the nest box should not have one. A large nearby tree will offer a place for the bluebird fledglings to fly to for safety. Keep the box in the open with the entrance pointed away from prevailing winds and at least 50 feet (15 meters) away from the woodland edge (to discourage House Wrens from using it).

If you would like to make your own box, here is a bluebird box plan from the North American Bluebird Society. You can also buy a nest box from your local bird store for the species you are interested in. A nest box should always be on a pole and not on a tree where predators can reach it. Boxes should also have a predator guard attached to the pole and below the box to keep out Raccoons (Procyon lotor) and Black Rat Snakes (Pantherophis alleghaniensis), which prey on bluebird adults and young.

Clean out the nest box after the birds have fledged. The adults will sometimes have another brood. It is also important to clean and disinfect the box with a weak bleach solution at the end of the nesting season, since bluebirds and other cavity-dwelling species will use the box during the winter as a place to roost and stay warm.

Beside its size, the location of a nest box will determine what species of bird you will attract. Black-capped Chickadees and Tufted Titmice prefer boxes placed in woodlands and forest edges, often under or near mature trees. House Wrens like to nest near brushy areas and in woodland edges. You’ll know you have a House Wren nest if you see the inside of the box filled with sticks. Here is a nest box plan from Cornell University that works for Black-capped Chickadees, Tufted Titmice, and House Wrens.

Black-capped Chickadees will nest in abandoned Downy Woodpecker (Dryobates pubescens) holes, but they will also excavate their own holes in rotten branches, often selecting birch (Betula sp.) or alder (Alnus sp.) trees. Chickadees like to have a 4 to 5 inch (10 to 13 centimeter) layer of wood shavings inside the box, so that they can excavate a nest cavity.

You can create woodpecker habitat by keeping a dead tree as a snag. In my yard, I had loggers leave a 20 foot (6 meter) tree stump from an American Ash (Fraxinus americana) that died. As the standing trunk decomposes it will provide an insect smorgasbord for a host of bird species as well as nesting sites.

Having a yard with mostly native plants will attract many insects that will feed birds and their young. Human activities hurt many bird species, but we can also do our part to support birds. Planting native herbaceous plants, trees and shrubs and putting up nest boxes are great ways to help.

Even with mid-February’s chill, ice, and snow, there are signs that spring is on the way. On a recent walk I noticed that the flower buds on Sugar Maples (Acer saccharum) and Red Maples (Acer rubrum) are beginning to swell. Trees have evolved internal mechanisms that sense winter’s passing. These mechanisms are influenced by an accumulation of temperature swings through time. These combinations of temperature changes will eventually lead to budburst, which in this case leads to flower buds bursting open. Sap is also flowing upward from the roots now through the xylem, so maple sugaring season is upon us.

Look now in forested wetlands and along slow-moving streams and you might find the first wildflower of spring: Eastern Skunk Cabbage (Symplocarpus foetidus), a plant with amazing adaptations (I wrote about them in an April 2020 post).

Last week I heard a male Tufted Titmouse (Baeolophus bicolor) singing “peter-peter” for the first time since last fall. A bird’s brain has hormones that, when activated by increasing day length, trigger the bird to start singing and defending its territory in preparation for attracting a mate and nesting. The Northern Cardinal (Cardinalis cardinalis), Mourning Dove (Zenaida macroura), and Song Sparrow (Melospiza melodia) are now joining in.

Downy Woodpeckers (Picoides pubescens) have started drumming. They don’t drum to find food, but use a dead or hollow tree limb to enhance the sound. They drum as a territorial “call” and to court a mate.

The American Robin (Turdus migratorius) has been called the first bird of spring. Not so—some robins are winter residents here and don’t fly south. In winter they change their diet from worms and insects to berries in wetlands and other habitats. Among northward spring migrants, the first true “bird of spring” is the Red-winged Blackbird (Agelaius phoeniceus). Look in freshwater marshes and overgrown fields now for the males, who arrive first to set up territories. Listen for their “konk-a-ree” song.

Love is in the air for resident Red-tailed Hawks (Buteo jamaicensis) and Red-shouldered Hawks (Buteo lineatus). They are pairing up and courting. I can hear a Red-shouldered’s loud “keer-keer-keer-keer” as I write this. In early March look for their amazing aerial courtship displays, complete with pairs diving toward each other from great heights.

It’s also Valentine’s Day for the Eastern Striped Skunk (Mephitis mephitis) and for the first time since fall I just smelled one. It’s the beginning of the mating season for them, from now until the end of April. After mating, females go back to their burrows and in about 60 days give birth to an average of six kits. These skunks don’t hibernate like the Woodchuck (Marmota monax), but are catnappers, sleeping on and off throughout the winter. They’re mostly living off their accumulated fat and often lose about half of it by spring.

It’s a great time to start a nature journal to log the many changes you can see now. Happy Spring!

During a recent ecosystems program I gave to an elementary school class one student was concerned that animals would die because temperatures have been so cold. I assured her that wouldn’t happen, because animals have evolved some amazing adaptations to deal with harsh winter weather.

If you have looked out your window lately and have seen a “fat” bird, you’re not imagining that. It has fluffed its feathers to create air pockets among the many dense, down feathers that hold heat next to its body. It’s like wearing an extra layer of long underwear. The bird’s outer contour feathers seal the trapped air. Also, birds that inhabit colder environments like ours have higher feather mass and more dense downy feathers than those from warmer habitats.

Birds can lose body heat through their beaks and feet, so they often tuck their heads down over their shoulder or under a wing. They keep their feathers dry and waterproof by spreading oil from glands at the base of the tail on their feathers, in a process called preening.

Black-capped Chickadees (Poecile atricapillus) have some remarkable strategies to stay alive and healthy in winter. When they travel together they help each other find food. Birds burn calories when they fly. By eating overwintering insects and seeds, which are often high in fat, birds maintain their warmth and fuel metabolism. Chickadees and most other winter birds can also generate heat and stay warm by shivering.

A chickadee’s normal daytime body temperature is about 108 °F (42 °C ). Researchers have found that a chickadee at night can lower this by 12 to 15 °F (6 to 8 °C) and enter a state of torpor. By reducing its metabolism in this way, it can conserve 25% to 30% of its fat stores from the previous day.

Last fall, chickadees started caching seeds. They are remarkable for their memory and remember hundreds of cracks and crevices in bark where they have stored food. Studies have shown that a chickadee’s hippocampus, the part of the brain responsible for memory, expands by 30% in the fall. In the spring when food is more plentiful it shrinks back to its normal size.

Thick brush, as well as dense conifers like spruces (Picea sp.), junipers (Juniperus sp.), and pines (Pinus sp.), can keep animals warm by reducing their exposure to the wind. If a thick, insulating layer of snow covers the branches, all the better.

Golden-crowned Kinglets (Regulus satrapa), one of the smallest birds of the Northeast, have been observed feeding at –30 °F (–34 °C). Like chickadees, they often travel in groups and can be in a mixed flock with chickadees, nuthatches, and other birds. How do these tiny birds—which lose more heat than larger birds—keep warm at night?

Biologist Bernd Heinrich observed four Golden-crowned Kinglets huddled together at night on a conifer branch in thick cover. By huddling or roosting in cavities animals can heat the air around them. Some species of woodpeckers chisel out roosting cavities in tree trunks and usually spend the night in them individually. Eastern Bluebirds (Sialia sialis) and flying squirrels (Glaucomys sp.) sometimes use woodpecker holes at night. More than a dozen Eastern Bluebirds have been found huddled together for the night in a bluebird nest box.

You can help birds and other wildlife get through the winter by planting native, berry-producing shrubs and trees. Coniferous trees and shrubs provide winter cover and seed from cones, and shelter wildlife from wind and weather. A wildlife brush pile can help too. Set up a feeding station with high quality seed for birds, particularly during late winter and ice storms when the seed and fruit crop is lower. That way, you can admire winter wildlife up close and help them keep warm.