The Charming Thistle Bird

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.

A male American Goldfinch eating thistle seed, a favorite food. In summer plumage, male goldfinches are easy to identify with their bright yellow back and belly, black cap and wings. Photo by Will Sweet, CC BY 2.0 https://creativecommons.org/licenses/by/2.0, via Wikimedia Commons.
When in breeding plumage, female American Goldfinches can be told from males by their olive color on the crown and back. Photo by Omaksimenko, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons.

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.

If you have Purple Coneflowers (Echinacea purpurea) in your garden, don’t cut the flowers at the end of the growing season. Save them for goldfinches, who love to eat the seeds through the winter.

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.

Notice the Brown-headed Cowbird egg in this Eastern Phoebe nest. Cowbirds are nest brood parasites. Because American Goldfinches feed their young a mostly vegetarian diet, cowbird chicks in goldfinch nests usually don’t get enough insect food to survive. Photo by Galawebdesign, CC BY 3.0 https://creativecommons.org/licenses/by/3.0, via Wikimedia Commons.

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.

Holding a Piece of Connecticut’s Tropical Sea Floor

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.

A paleo map of what Earth probably looked like during the Ordovician Period, 458 million years ago. Notice the early North American continent, called Laurentia, is located along the equator, and is tropical. Illustration by NPS, Public domain, via Wikimedia Commons.

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.

The author holding a piece of ancient sea floor – Stockbridge Marble. Photo by Willow Sirch.

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!

Fossilized stromatolites in the Hoyt Limestone near Saratoga Springs, New York. Photo by Rygel, M.C., CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0&gt;, via Wikimedia Commons.

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.

This Generalized Connecticut Bedrock Geologic Map (broken into quadrants here) was produced by the Connecticut Geological and Natural History Survey in 1990. It is based on the Bedrock Geological Map of Connecticut compiled by John Rodgers at Yale in 1985. The colors represent different kinds of bedrock formed at different ages. Notice the bedrock illustrated in a sky blue color on the upper left corner of the state. This represents where Stockbridge Marble can be found.

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).

A calcareous fen found in New York state. Photo by Gregory J. Edinger, New York Natural Heritage Program.

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.

These Shrubs are the Cat’s Meow

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.

What we think of pussy willow catkins are the male flowers. Notice the yellow anthers on these male catkins. The flowers have lots of pollen for early bees and butterflies. Photo by the author.

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.

Here is a close-up of a shrub with female flowers that provide nectar for insects. Notice the greenish styles and white stigmas. Photo by the author.

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.”

Even from a distance, you can tell the sex of these Pussy Willows. Notice the male shrub with large white catkins in the middle of this photo. It’s surrounded by female shrubs with greenish catkins. Photo by the author.

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.

Pussy Willows provide nectar for early emerging, adult Mourning Cloak butterflies. Mourning Cloaks also lay their eggs on Pussy Willow leaves, providing food for the butterfly larvae. Photo by Mykola Swarnyk, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0&gt;, via Wikimedia Commons.

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).

The thick branches of Pussy WIllows provide good nesting cover for Yellow Warblers. Photo by Mykola Swarnyk, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons.

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.

The Tail Wagger Returns

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.

It’s not a problem that Eastern Phoebes look rather drab in color, because they help you realize spring is here. Photo by Manjithkaini at English Wikipedia, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons.

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.

Looks like it’s getting a bit crowded! These chicks are about ready to fledge. Notice the nest is sitting on a pipe under an eave. Photo by Fredlyfish4, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons.

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.

Notice the cowbird egg that was left in this clutch of phoebe eggs. Photo by Galawebdesign, CC BY 3.0 https://creativecommons.org/licenses/by/3.0, via Wikimedia Commons.

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.

All Boxed Up

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.

Black-capped Chickadees are one of the species that use cavities made Downy Woodpeckers. Photo by Rhododendrites, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons.
Besides using woodpecker holes, Black-capped Chickadees are one of the few birds which excavate their own cavities. They usually use a dead snag with soft wood. Photo by Seney Natural History Association, CC BY-SA 2.0 https://creativecommons.org/licenses/by-sa/2.0, via Wikimedia Commons.

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.

Eastern Bluebirds usually nest in cavities made by woodpeckers. They sometimes use holes in wooden fence posts. This post makes a nice perch for a female Eastern Bluebird. Photo by Dakota L., CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons.

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).

Introduced House Sparrows, like the male shown here, try to outcompete bluebirds and other birds for next boxes. They will kill young bluebirds and throw out bluebird eggs. If you see one trying to nest in your box, just keep pulling out nest material. Photo by Arnold Paul, CC BY-SA 2.5 https://creativecommons.org/licenses/by-sa/2.5, via Wikimedia Commons.

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.

Here is a properly mounted bluebird box. Notice the tubular predator guard below the house as well as the hardware cloth cube in front of the entrance hole. This screening makes it hard for a raccoon to reach into the box. Photo by Virginia State Parks staff, CC BY 2.0 https://creativecommons.org/licenses/by/2.0, via Wikimedia Commons.

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.

House Wrens are really easy birds to attract to a house. Photo by julian londono from Colombia, CC BY-SA 2.0 https://creativecommons.org/licenses/by-sa/2.0, via Wikimedia Commons.

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.

By having a variety of native plants, you will have a lot of insects. Butterfly and moth larvae, like this Noctuid Moth caterpillar (LIthophane antennata), make up the majority of the diet of nesting birds and their young. Photo by Beatriz Moisset, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons.

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.

In the Bitter Cold, Signs of Spring

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.

Even from a distance, you can see the flower buds on this Red Maple swelling. Photo by the author.

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).

Look now in forested wetlands and swamps for the inflorescence of Eastern Skunk Cabbage, considered the first “wildflower” of spring. Photo by Chris Norris.

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.

The Tufted Titmouse is one of the first resident birds to start singing in late winter. Photo by Basar, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons.

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.

Male Downy Woodpeckers begin drumming on hollow limbs and branches in late winter. They will also drum on metal gutters! Drumming is used to defend a territory and attract a mate. Photo by Mykola Swarnyk, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons.

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.

The first spring migrant is the Red-winged Blackbird. Males arrive in Connecticut in mid-February to begin setting up territories. Photo by Plismo, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons.

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.

By mid-February, Red-shouldered Hawks are pairing up and will soon begin building a nest. Photo by Andy Morffew from Itchen Abbas, Hampshire, UK, CC BY 2.0 https://creativecommons.org/licenses/by/2.0, via Wikimedia Commons.

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.

Love is in the air now for Eastern Striped Skunks. They mate from February to April. Photo by http://www.birdphotos.com, CC BY 3.0 https://creativecommons.org/licenses/by/3.0, via Wikimedia Commons.

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

Warming Up

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.

Sleeping birds, like this female Hooded Merganser (Lophodytes cucullatus), avoid heat loss by tucking their bills and feet under their feathers. Photo by Fiver, der Hellseher, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0&gt;, via Wikimedia Commons.

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.

Black-capped Chickadees can remember hundreds of places where they have cached seeds during colder months. Photo by Rhododendrites, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0&gt;, via Wikimedia Commons.

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?

Tiny Golden-crowned Kinglets are actively hunting and eating high fat, dormant moth larvae throughout the day to fuel their metabolism and keep warm. Photo by Melissa McMasters from Memphis, TN, United States, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0&gt;, via Wikimedia Commons.

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.

During cold weather, Eastern Bluebirds will often pile in together in tree cavities for warmth. Photo by Sandysphotos2009, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0&gt;, via Wikimedia Commons.

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.

Love Is in the Air

I’m not talking about an early Valentine’s Day celebration, but the time when Eastern Coyotes (Canis latrans var.) are seeking mates, if they don’t have already have one. Pairs are monogamous and will often stay together for several years. In Connecticut, January through March is their breeding season. An average of seven pups are born from April to mid-May. In the fall, dominant pups may remain in their parent’s territory, but others will disperse. It’s the parents and their young that are sounding off when you hear yips, yowls, barks, and other vocalizations.

Eastern Coyotes look somewhat like German Shepards but are leaner, with long legs, a pointy muzzle and long ears. Photo by U.S. Fish and Wildlife Service Northeast Region, PDM-owner, via Wikimedia Commons.

Coyotes have only been in Connecticut since the 1950s. The Western Coyote (Canis latrans) from the midwestern and western United States expanded its range eastward through Canada and down into the U.S. Northeast and mid-Atlantic states. Along the way it interbred with the Canadian Gray Wolf (Canis lupus) and domestic dogs (Canis familiaris). The Eastern Coyote is a hybrid. Studies have shown that genetically the animals in the Northeast are on average a mix of about 60% coyote, 30% Gray Wolf, and 10% domestic dog.

Eastern Coyotes pair up and mate between January and March. Gestation is 63 days. Females will stay underground with the pups until their eyes open about 12 days later. Photo by http://www.ForestWander.com, CC BY-SA 3.0 US <https://creativecommons.org/licenses/by-sa/3.0/us/deed.en&gt;, via Wikimedia Commons.

Even with this mixed parentage, coyotes today avoid contact with dogs. So the idea of the “coy-dog” is actually more of a myth, as breeding between the two species is rare. Because both coyote parents raise the young, if a male domestic dog bred with a female coyote the male would not help with care and the pups probably wouldn’t survive.

The Eastern Coyote is larger than its western counterpart (due to its wolf ancestry) and weighs about 20 to 30 pounds (9 to 13 kilograms) more than the Western Coyote (Canis latrans texensis). Eastern animals hold larger and more extensive territories as well. The Eastern Coyote looks like a small German Shepard, with pointy ears, long legs, a long muzzle, yellow eyes, and a long, straight, black-tipped bushy tail.

There is a striking difference in size between Eastern and Western Coyotes. It is thought that Eastern Coyotes are larger because of Gray Wolf ancestry. The skull on the right is an Eastern Coyote. Photo by Mrgordon, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons.

Coyotes are extremely adaptable and exploit a variety of habitats, even developed populated places. Their diet includes the White-footed Mouse (Peromyscus leucopus), the Eastern Cottontail (Sylvilagus floridanus), Woodchuck (Marmota monax), squirrels (Sciurus spp.), White-tailed Deer (Odocoileus virginianus), fruit, carrion, and even garbage.

Some coyotes prey on small livestock, poultry, and small pets. Poultry can be locked up at night and guard dogs help prevent attacks on sheep. People who let their cats roam free outside should know that they are vulnerable to coyote attacks. (Cats should be kept inside for another reason—millions of threatened birds are killed each year by free-roaming cats.) Small, unleashed dogs under 25 pounds (11 kilograms) are also vulnerable. I remember watching a sensational local newscast about a large dog that had been attacked by “vicious” coyotes. What the reporter failed to mention was that the dog was unleashed and ran up to a den where a mother coyote had defended her pups.

Never feed coyotes. It causes them to associate people with food and leads to negative human–animal interactions. With the thousands of coyotes in the United States today, there have been only two documented human fatalities in history from coyote attacks.

Coyotes have been persecuted. Although they continue to be trapped, shot, and poisoned, they will come back resiliently after population losses. Let them be. They are magnificent animals that are part of our forest ecosystem and are here to stay.

The Waxwing Tree

Lately I’ve been noticing lots of different birds eating the light blue, berry-like cones found on Eastern Red Cedar (Juniperus virginiana). I am not sure whether Red Cedars have mast years (when they produce more fruit, like oaks do), but they seem to have their branches covered this year.

The blue, berry-like cones of Eastern Red Cedar are a favorite of birds. Photo by Famartin, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0&gt;, via Wikimedia Commons.

Eastern Red Cedar is one of the top 10 trees for attracting birds. The Northern Mockingbird (Mimus polyglottos), American Robin (Turdus migratorius), Brown Thrasher (Toxostoma rufum), and Yellow-rumped Warbler (Setophaga coronata) all love its cones. But it is the Cedar Waxwing (Bombycilla cedrorum), often spotted feeding on Red Cedars, that is named for this tree. There is also a small, colorful, green butterfly—the Juniper Hairstreak (Callophrys gryneus)—that is so named because its larvae feed on Eastern Red Cedar leaves.

The Cedar Waxwing is named after Eastern Red Cedar. Photo by Andrew C, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0&gt;, via Wikimedia Commons.
The larvae of the Juniper Hairstreak (Callophrys gryneus) feed on Eastern Red Cedar leaves. Photo by khteWisconsin, PDM-owner, via Wikimedia Commons.

The Eastern Red Cedar is actually a juniper, not a true cedar. I feel to show this its common name might be more appropriately hyphenated as “Eastern Red-cedar.” However, I haven’t seen this done lately. True cedars, such as the Atlas Cedar (Cedrus atlantica), are found in the Mediterranean. The Himalayan Cedar (Cedrus deodara) is from the western Himalayas. These are in the pine family (Pinaceae). The Eastern Red Cedar is a member of the cypress family (Cupressaceae), which includes the Bald Cypress (Taxodium distichum) and Arborvitae (Thuja occidentalis).

Eastern Red Cedar is a common tree in eastern North America. It is a pioneer species, one of the first species to colonize a cleared field in secondary forest succession. As the trees grow larger, they provide shade for other trees, like oaks and maples, that eventually overtop and shade out the cedars as a new forest begins to grow. However, without competition Eastern Red Cedar can be a long-lived tree. One tree is known to have a recorded age of more than 900 years!

Eastern Red Cedars are one of the first trees to colonize a field. They are also common along roadsides as well. Photo by Nicholas A. Tonelli from Northeast Pennsylvania, USA, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0&gt;, via Wikimedia Commons.

There are many uses for Eastern Red Cedar. In the early 1900s, Red Cedar was the tree of choice used to make pencils. So many trees were apparently cut for commercial production that Red Cedar became scarce and other trees and synthetic materials were substituted. It is still common today to use its wood for chests and closets because its scent repels moths. The pinkish heartwood of Red Cedar is extremely rot resistant and is often used for fenceposts.

Red Cedar was once the wood of choice for making pencils. The photo of this cedar mill was taken around 1890.
Unknown author, Public domain, via Wikimedia Commons.

Some tribal nations have historically used juniper wood poles to mark the changing alignment of the sun during the seasons, as was done at Stonehenge. The Cahokia Woodhenge was a series of timber circles during the pre-Columbian Mississippian culture in western Illinois. One circle nicknamed “Woodhenge III,” had 48 massive juniper posts in a circle that was 410 feet in diameter and a pole in the center. Some tribal nations continue to use juniper wood in ceremonies today.

Cedar “berries” are used to flavor gin—not Eastern Red Cedar, but another native species, Common Juniper (Juniperus communis). Apparently Common Juniper, which also grows in Europe and Asia, has the best flavor.

In the landscape, Eastern Red Cedar has the best drought resistance of any of our native coniferous (cone-bearing) trees, which is good to know with the challenges of climate change. This tree can tolerate a variety of conditions, from dry to moist, and alkaline to acid, soils. It also is salt tolerant and can be grown next to roads that are treated in winter. Red Cedars are the alternative host for Cedar Apple Rust (Gymnosporangium juniperi-virginianae), a fungus that infects apple trees. So it would be best to avoid planting a Red Cedar near any apple trees.

If you are lucky enough to have an Eastern Red Cedar in your yard or nearby open space, you’ll want to protect it. And, you’ll be helping out quite a few birds as well as other wildlife into the bargain.

Don’t Bug Me Now

The winter solstice—the shortest day of the year and the official start of winter—has come and gone, and the days are now getting longer.

In this cold, dormant time, it might come as a surprise to learn that insects survive the winter. They have various strategies to do this. Many species go through diapause, a delay in development in response to adverse environmental conditions. The eastern population of the Monarch (Danaus plexippus) butterfly migrated last fall to overwintering sites in the Oyamel Fir (Abies religiosa) forests of Mexico. They usually arrive there around the Día de las Muertos, which is celebrated November 1 and 2. They rest there and won’t feed on milkweed until temperatures are warmer. Then they begin to migrate back north. And the reason you can find the Mourning Cloak (Nymphalis antiopa) butterfly flying around so early in the spring (often in March in Connecticut!) is because in winter they hibernate as adults in tree holes and other crevices.

Mourning Cloak butterflies can be active in late winter and early spring because they have overwintered as adults in tree holes and crevices. This butterfly is using the heat from the dark rock to warm up. Photo by Ryan Hodnett, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0&gt;, via Wikimedia Commons.

Many lady bugs, or ladybird beetles (family Coccinellidae), will overwinter as adults, piling on one another in big groups inside hollow logs and under rocks. This helps them stay hydrated and avoid predators. Last fall you might have noticed their large gatherings around your dark shutters and white-framed windows. Usually this is an introduced species, the Asian Lady Beetle (Harmonia axyridis). These beetles will sometimes crawl into a home through cracks. When disturbed, they emit an acrid odor and can stain surfaces with a yellow secretion.

This cluster of Asian Lady Beetles gathered together in a South Dakota farm building. Photo by Jared Birk, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0&gt;, via Wikimedia Commons.

If you see a moth flying at night in December in Connecticut, it is likely the male Winter Moth (Operophtera brumata). This invasive species, introduced from Europe, can defoliate oak and maple trees as a caterpillar (larva). The larvae burrow into the ground to pupate and the adults emerge in late fall and early winter. In cold temperatures male moths rapidly vibrate their flight muscles to warm themselves and then fly off to seek out females. Females don’t fly, but crawl up a tree and emit a pheromone to attract males.

It’s strange to see a moth flying around in the winter, as this Winter Moth does. This invasive species can cause damage to native trees such as oaks and maples. Photo by Ben Sale from UK, CC BY 2.0 https://creativecommons.org/licenses/by/2.0, via Wikimedia Commons.

Some insects overwinter as larvae. The Wooly Bear caterpillar, the larva of the Isabella Tiger Moth (Pyrrharctia isabella), are seen traveling across roads and paths in the fall. They are now dormant under the heavy cover of leaf litter. These caterpillars produce glycerol, an antifreeze, which keeps their cells from freezing.

A Luna Moth spends the winter as a pupa or cocoon. In the fall, the larva will wrap leaves around itself with silk and then change into a pupa. If the leaves containing the cocoon fall to the ground before the adult emerges in the spring, it will spend the winter hidden in leaf litter. Photo by Carlowenby, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0&gt;, via Wikimedia Commons.

Insect species that spend the winter as an egg include praying mantids. Before she dies in the fall, an adult female mantid will lay an inch-long (2.54 centimeters) frothy sac, which hardens into a protective egg case, or ootheca. I once made the mistake of bringing an egg case indoors one fall and that winter 100 young hatched!

A Praying Mantid ooetheca or egg case. Photo by Dhrm77, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0&gt;, via Wikimedia Commons.

We might not be thinking of insects and other invertebrates as active now. But many of them are. Beneath the ice of ponds and streams the immature stages of stoneflies (order Plecoptera), caddisflies (order Trichoptera), mayflies (order Ephemeroptera), and dragonflies (order Odonata) are actively feeding on smaller aquatic invertebrates or plant material, depending on the species. These insects are growing and adding body mass so they can emerge as fully flighted adults in the spring. Dragonfly nymphs, like the adults, are carnivorous, feeding on other invertebrates and even tadpoles and salamander larvae. Some spend a few years as a nymph before maturing into an adult.

Dragonfly nymphs are one of many aquatic macroinvertebrates active during the winter. The nymphs are one of the top aquatic predators for their size. Photo by Judy Gallagher, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0&gt;, via Wikimedia Commons.

The larvae of caddisflies are found in a wide variety of aquatic habitats, including streams, rivers, lakes, ponds, and vernal pools. Many species of caddisfly larvae use silk to make protective outer cases with gravel, sand, twigs, bitten-off pieces of plants, or other debris. The larvae feed in different ways depending on the species. Some are predators, some shred leaves, others graze on algae or collect particles from the water column or on the bottom.

We don’t often think about insects during the winter, or just believe that most have died. If we do see one, we think it is an anomaly or accident of nature. In fact, many insects are still living with us, either dormant or active, during the winter months.