Plant This, Not That

As of this past weekend, most of the leaves are off the trees and the scarlet foliage of Burning Bush or Winged Euonymous (Euonymous alatus) is easily seen. It’s a dangerous beauty. Now you can see clearly how prevalent this shrub is—and it is spreading. Winged Euonymous dominates many roadsides. If you delight in the brilliant red of this shrub, you might think this is a good thing. In reality, there are problems with this plant and other non-native, invasive species on the Connecticut Invasive Species List . Birds eat its oblong, scarlet berries and spread the seeds. The plants grow and choke out native plants that wildlife have evolved to eat, thereby threatening local ecosystems.

Burning Bush or Winged Euonymous (Euonymous alatus) is a commonly planted but very invasive shrub. Notice the wings along the green and brown branches. Photo by Steve Law, CC BY-SA 2.0 <https://creativecommons.org/licenses/by-sa/2.0&gt;, via Wikimedia Commons.

The fruit of many invasives is high in carbohydrates, whereas berries from native shrubs and trees also have the fats and proteins that wildlife, including birds, need to survive migration or get through the winter. It would be as if you ate just candy bars instead of a varied diet of fruits, vegetables, nuts, and meat. Like humans, birds don’t always eat what’s good for them now that these “new” plants are on the scene.

The leaves of most invasives can’t be digested by caterpillars, the primary food that birds feed their young during the nesting season. It can take up to 9,000 caterpillars for parent Black-capped Chickadees (Poecile atricapilus ) to successfully raise a brood.

What can you do? There are many native alternatives important to our ecosystem even in our yards and neighborhoods. Instead of Burning Bush, plant native Lowbush Blueberry (Vaccinium angustifolium) or Highbush Blueberry (Vaccinium corymbosum). Lowbush Blueberry only grows a few feet high and Highbush Bluebery tops out at 6 feet (2 meters). Both have lovely scarlet fall foliage. Try beating the birds to the delicious berries!

The foliage of Lowbush Blueberry (Vaccinium angustifolium) is just as lovely as that of Burning Bush . The plants requires bumble bees to “buzz pollinate” its flowers. Photo by Andy Brand.

Chokeberries (Aronia spp.) are shrubs with beautiful orange to red leaves in the fall. There are two species native to the eastern United States: Red Chokeberry (Aronia arbutifolia) with red berries and Black Chokeberry (Aronia melanocarpa) with black berries. They both reach a maximum of 8 feet (2.5 meters) high, although there are varieties in the garden trade that are smaller.

Red Chokeberry (Aronia arbutifolia) is another great alternative to Burning Bush. It’s tart, red berries are eaten by birds later in the winter after they sweeten. The berries are also great for jams. Photo by Earth Tones Native Plant Nursery.

Japanese Barberry (Berberis thunbergii) is another often planted invasive shrub that then escapes into surrounding woodlands. Its oblong, scarlet berries are also eaten and spread by birds. I have seen some forests where Japanese Barberry has taken over the entire understory. Research shows that the White-footed Mouse (Peromyscus leucopus), a vector for Lyme disease, likes to hide under the thick cover it provides, so the shrub can even adversely affect human health.

Japanese Barberry (Berberis thunbergii) can take over the entire understory of woodland tracts, choking out other plants. Its leaves emerge early in the spring, blocking needed light for native wildflowers. White-footed Mice (Peromyscus leucopus), a vector for Lyme Disease, like to hide in its thick foliage. Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org, CC BY 3.0 US <https://creativecommons.org/licenses/by/3.0/us/deed.en&gt;, via Wikimedia Commons.

What to plant instead? A great alternative is Winterberry (Ilex verticillata), which is a deciduous holly. It’s a native of wetland edges, but is very adaptable to a variety of soils in part to full sun. Its round, scarlet fruits hanging on through the winter contrast nicely with its bare branches. One of my personal highpoints was once watching a flock of bluebirds flying in and feeding on its fruit during a raging snowstorm—a parade of red, white, and blue.

In the wild, Winterberry’ (Ilex verticillata) is found in damp soils along wetland and stream edges, but is adaptable to many soils in the garden. Photo by Richard Webb, Self-employed horticulurist, Bugwood.org, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0&gt;, via Wikimedia Commons.

Autumn Olive (Eleagnus umbellata) and its cousin Russian Olive (Eleagnus angustifolia) originally were planted by highway departments and conservationists to help hold soils and attract wildlife, without realizing that these species would spread out of control. A much better choice is the native American Hazelnut (Corylus americana). Its edible nuts are so loved by squirrels, foxes, Northern Bobwhite, Ruffed Grouse, Wild Turkey, and woodpeckers that it is hard to save some for yourself! The shrub is very tolerant of a variety of soil and light conditions.

In 1959, this pamphlet was published by the USDA to encourage planting Autumn Olive (Eleagnus umbellata) for wildlife, not realizing how invasive the shrub is. Woops! Public domain.
Autumn Olive was once widely planted by highway departments along roadsides and interstates. Photo by College of Agriculture and Natural Sciences, University of Delaware.
American Hazelnut’s fruits are edible for a host of wildlife, including us. Notice the leaves eaten by insects, which is a good thing. Caterpillars feed on the leaves, and in turn supply food for birds. Photo by Steven Katovich, USDA Forest Service, Bugwood.org, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0&gt;, via Wikimedia Commons.
 

How about getting rid of invasive Asiatic Bittersweet (Celastrus orbiculatus) vines, beloved of home decorators at this time of year? It might look pretty on your mantle, but this plant is a harmful invasive in the wild. I am gradually getting rid of bittersweet in my yard. The vines are so prolific and grow so fast that in a few years they can climb a tree and eventually pull it down. Replace it with our native Carolina Rose (Rosa carolina). This shrub grows 3 feet (1 meter) high and spreads through rhizomes to form a good-sized patch.

The berries of Asiatic Bittersweet (Celastrus orbiculatus) have been used in holiday wreaths, with the fruits later disposed of in the backyard. This is a real problem as the vines can grow to take over the yard! Photo by Cbaile19, CC0, via Wikimedia Commons.
The native Carolina Rose (Rosa carolina) is a much better alternative to Asiatic Bittersweet. The shrub’s pink flowers attract a variety of native bees and butterflies. Photo by bobistraveling, CC BY 2.0 https://creativecommons.org/licenses/by/2.0, via Wikimedia Commons.

Japanese Honeysuckle (Lonicera japonica) is another common invasive vine. A much better alternative is the native Trumpet Honeysuckle (Lonicera sempervirens). Its tubular red or orange flowers, which hummingbirds adore, are beautiful along a fence or trellis. .

Another member on the CT Invasive Species list is Japanese Honeysuckle (Lonicera japonica). It can crowd out native plants and climb up fences and trees. Photo by Vinayaraj, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0&gt;, via Wikimedia Commons.
Unlike Japanese Honeysuckle, native Trumpet Honeysuckle (Lonicera sempervirens) is more restrained. Its tubular red flowers are a magnet for Ruby-Throated Hummingbirds (Archilocus colubris).. Photo by Stan Shebs, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0&gt;, via Wikimedia Commons.

Fall is a good time to plant. There is still time before the ground freezes, so grab a shovel and put in plants that satisfy our need for beauty, yet serve the native ecosystem well.

The Snapping Hazel

Leaves are fading to shades of brown and gray and dropping fast in the late fall winds as I walk along a local trail. At this time of year, I am always surprised when I come across a flash of bright yellow from the last native flowering plant of the year: the native American Witch-Hazel (Hamamelis virginiana). It’s a 20- to 30-foot (6- to 10-meter) small tree or shrub with crinkly, bright yellow ribbon-like petals that are often found among the medium-yellow autumn foliage. The flowers will last even after its leaves turn brown and fall off. Witch-Hazel blooms from September through November.

Look for American Witch-Hazel’s (Hamamelis virginiana) fragrant, crinkly-yellow flowers in November in Connecticut. It’s the last native flower of the year. Photo by Fritzflohrreynolds, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0&gt;, via Wikimedia Commons.

I have often wondered… what could pollinate a flower so late in the season, when all other flowers have  faded and the weather can be quite cold? Late-flying bees and parasitic wasps have been suggested, but biologist Bernd Heinrich discovered that a few species in the Owlet Moth family (Noctuidae) feed on the tree sap as well as nectar from the fragrant flowers of Witch-Hazel. How do they do it? They shake. By shivering its flight muscles, this moth can raise its temperature by 50°F (27.8°C) above the air temperature! And owlet moths are active at night, when they warm their bodies to 86°F (30°C) to be able to fly. They will lose this heat quickly, so they need to stop often to shiver again.

There are two other natives—Ozark Witch-Hazel (Hamamelis vernalis) and Big-Leaf Witch-Hazel (Hamamelis ovalis)—and two non-native witch-hazels—the Chinese Witch-Hazel (Hamamelis mollis) and Japanese Witch-Hazel (Hamamelis japonica). Unlike our native witch-hazels, these non-native species bloom in late winter and early spring. There are several hybrids of early, yellow-, orange-, or red-blooming cultivars of these.

Unlike American Witch-Hazel which blooms in late fall, Ozark Witch-Hazel (Hamamelis vernalis) blooms in the spring. It’s flowers can range from pale yellow to a dark, reddish purple. Photo by Cbaile19, CC0, via Wikimedia Commons.

The origin of the name Witch-Hazel is the Old English wice, meaning “bendable.” This may refer to the plant’s curved branching or that its branches are used by dowsers to find water, which was common until the beginning of the twentieth century. A dowsing rod allegedly points downward to water underground. The name “hazel” comes from the resemblance of Witch-Hazel fruit to the fruit of the unrelated American Hazelnut (Corylus americana).

Witch-Hazel ‘Diane’ (Hamamelis x intermedia ‘Diane’) is a hybrid of two Asian species, H. japanica and H. mollis.

The fruit of American Witch-Hazel is a two-part, greenish seed capsule that becomes woody. It takes eight months to one year for fruits to ripen. When this plant releases its seeds, it does it in a spectacular way. The outer layer of the ripe fruit both shrinks and expands, constricting the middle section, and forcing the seeds out with an audible snap or crack at more than 32 feet (10 meters) per second! Witch-Hazel is also called “Snapping Hazel” because of this. A ridge in the fruit’s inner chamber causes the seed when “fired” to spin like a bullet up to 430 times per second. The fruit can send the seed up to 30 feet (10 meters) away, an evolutionary advantage to reach potentially improved growing conditions.

In the this photo you can see last’s year’s fruits of American Witch-Hazel. The fruits have already ‘fired’ their seeds. Photo by H. Zell, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0&gt;, via Wikimedia Commons.

According to entomologist Doug Tallamy, there are 60 species of butterflies and moths that feed on Witch-Hazel leaves. Ruffed Grouse, Northern Bob-White, Wild Turkeys, Eastern Gray Squirrels, and Eastern Cottontail Rabbits all eat Witch-Hazel fruit.

American Witch-Hazel is also useful to people. Native Americans used extracts from the branches and leaves medicinally, such as boiling the stems to make a decoction to treat swelling and inflammation. Early settlers in New England adopted these practices and use became widely established.

Missionary Dr. Charles Hawes learned of Witch-Hazel’s therapeutic properties and created his own extract by steam distillation of the twigs and bark. “Hawes Extract” was first produced and sold in Essex, Connecticut, by druggist Alvan Whittemore in 1846.

Thomas Newton Dickinson, Sr., refined Hawes’s process and is credited with the first commercial production of Witch-Hazel extract, also in Essex, Connecticut, in 1866. After his death his two sons, Thomas N. Dickinson, Jr., and Everett E. Dickinson, continued the family business with competing “Dickinson’s” businesses in different towns.

Eventually, the two companies came under the same corporate ownership. Today, Dickinson Brands still sells Witch-Hazel under the T. N. Dickinson and Dickinson’s labels. Witch-Hazel extract is used as an astringent to remove oils and impurities from the skin and also as an eye wash. Many people swear by it. Clearly there is more to Witch-Hazel than meets the eye. From its lovely delicate flowers that bloom when few flowers are still around, to its unique seed dispersal, to its long history as a useful plant to humans, the remarkable Witch-Hazel has much to recommend it.

They’re on the March

We often think of migration as long-distance treks by birds, mammals, and fish traveling to wintering or nesting grounds. Animal migrations, however, can be short. They can even happen right in your own yard or neighborhood. Right now, Banded Woolly Bear caterpillars (Pyrrharctia isabella) are on the move to find places to overwinter, such as under a log or in leaf litter. You can see them crawling around in many different habitats. Taking a walk around the neighborhood recently, I spotted quite a few and helped them cross the road.

Looking at this Woolly Bear caterpillar, will it be a mild winter? In reality you can’t predict how severe the winter will be based on how thick the brown or black bands are, but it is fun to think about! Photo by Micha L. Rieser, Attribution, via Wikimedia Commons.

The Woolly Bear caterpillar is the larva of the Isabella Tiger Moth. They are found throughout most of the United States, Canada, and Mexico. These two-inch (5 cm) caterpillars are usually black on the ends and brown in the middle. If you have never touched a Woolly Bear, they don’t actually feel like wool. They are covered with 13 rows of soft bristles called setae.

There is some weather folklore associated with Woolly Bears. You might have heard that if the caterpillars have a wide brown middle band, it will be a mild winter. Or if the black bands at the end are wide and the middle brown band is narrow, expect cold and snow and a more severe winter. In reality, differing band length is partly due to genetics and how mature the caterpillar is, as the brown bands tend to widen with age. Research suggests wetter weather can also widen the black bands.

Other lore has to do with direction. If the caterpillar is traveling south, expect a harsh winter. If it is going north, winter will be mild. I’m not sure about east or west though!

Woolly Bear larvae will spin cocoons and after a few weeks, hatch into two inch (5cm) Isabella Tiger Moths. Isabella Tiger Moths are sexually dimorphic, meaning males and females are of different size or color. The photo above is a male, as males have lighter lower hind wings. Females have a rosy or deeper orange hind wing. Photo by Andy Reago & Chrissy McClarren, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0&gt;, via Wikimedia Commons.

Woolly Bear larvae have been found as far north as the Arctic, where temperatures can reach minus 90°F (–68°C)! These larvae are amazingly adapted to get through harsh winters—their bodies produce a cryoprotectant, an anti-freeze with glycerol, that keeps cells from freezing. The caterpillar’s setae also protect it from fluctuating winter temperatures. When spring temperatures rise to 50°F (10°C), the larvae will spin cocoons and a few weeks later pupate into adults.

In Connecticut, there are two broods of Woolly Bears. The first brood ecloses, or hatches, from cocoons and emerges as adult Isabella Tiger Moths in mid-summer. The second brood overwinters as larvae to pupate in the spring. Female moths put out a scent to attract males and after mating will lay batches of 100 or more eggs. The eggs hatch four to five days later. Woolly Bear larvae are generalist feeders and eat a variety of herbaceous plants, shrubs, and trees.

Isabella Tiger Moth females lay up to 100 eggs in batches. These eggs are just about ready to hatch as you can see the young brown and black larvae inside. Photo by JGanance, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0&gt;, via Wikimedia Commons

Next time you see a Woolly Bear caterpillar, you can thank yourself for leaving leaves and logs in your yard to help them to get through the winter.

Is Connecticut Their Florida?

Retirees who want to escape the cold and ice to spend the winter down south are known as “snowbirds.” Actually, this nickname describes the Dark-eyed Junco (Junco hyemalis). Juncos are arriving here now after spending the summer nesting in the mountains of New England and in the Canadian Boreal Forest. They will head back north next spring. In winter they feed on seeds of plants many of us consider “weeds,” including Chickweed (Stellaria media), Lambsquarters (Chenopodium album), and Wood Sorrel (Oxalis stricta). You will also see juncos at feeders. With their slate-gray backs and upper bellies, and white outer tail feathers that flash as they fly away, they are easy to spot.

Besides migrating south, Dark-eyed Juncos (Junco hyemalis) also undergo a vertical migration, nesting on mountain tops and wintering in the valleys. Photo by Mykola Swarnyk, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0&gt;, via Wikimedia Commons

The smallest bird of the winter woods, not much larger than a Ruby-throated Hummingbird (Archilochus colubris), is the Golden-crowned Kinglet (Regulus satrapa). This species spends the summer nesting in northern coniferous forests but lives in a variety of forest habitats here in winter. I’ve even seen it flitting among the oaks growing along New Haven streets. Being so small, it is in constant motion, continually foraging for wintering insects and their eggs among bark and branches to fuel its metabolism. It would starve if it could not find food for a few hours on a cold day. Listen for its call, a high-pitched “tseet-tseet-tseet,” as it feeds.

“Energizer Bunnies” of the bird world, Golden-crowned Kinglets (Regulus satrapa) are constantly moving looking for food to fuel their high metabolism. Photo by Melissa McMasters from Memphis, TN, United States, CC BY 2.0

White-throated Sparrows (Zonotrichia albicollis) are arriving now. You can tell this bird from other sparrows by its black and white (sometimes tan) striped head and white throat. Look for them on the ground in woods and brushy edges. They can also be easily identified by their loud “chink” call. The White-throated Sparrow is one of the few birds that sings during the winter. Listen for its plaintive “Old-Sam-Peabody-Peabody” song. You will see both Dark-eyed Juncos and White-throated Sparrows on the ground under your bird feeders.

White-throated Sparrows (Zonotrichia albicollis) are a larger, quite vocal winter visitors told from other sparrows by their white throats and black and white-striped caps. Photo by Ryan Hodnett, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0&gt;, via Wikimedia Commons.

Some bird species that usually stay north in the winter will fly south during an irruption, a mass movement to another location that occurs periodically. An irruption is happening this year for some of these boreal migrants. Rather than being due to cold temperatures, this movement is actually tied to food availability. When the fruit and seeds of spruces, pines, mountain ash, and other trees are scarce in the north, some birds seek food elsewhere. The Winter Finch Forecast (maintained for decades by biologist Ron Pittaway, who recently passed the torch to Tyler Hoar) uses reports from foresters, researchers, naturalists, and other observers about the northern tree seed crop to predict which bird species will fly south or west.

Boreal migrants spotted at feeders here recently confirm this forecast: the Purple Finch (Haemorhous purpureus), Pine Siskin (Spinus pinus), and another migrant (not a finch), the Red-breasted Nuthatch (Sitta canadensis).

You can tell a male Purple Finch from the more common male House Finch (Haemorhous mexicanus) by the deeper color on the Purple Finch’s head and upper back—it looks as if it was dipped in raspberry juice. The male House Finch’s more reddish head color does not extend down its back. Purple Finches like to eat black oil seed at feeders.

Another boreal migrant during irruptions includes the Purple Finch. Males can be told from the more common male House Finches by looking like they were dipped in raspberry juice, rather than the male House Finches more reddish head and upper belly. Both female Purple Finches and House Finches look very similar, but female Purple Finches are more stockier looking and have darker streaks along the belly. Photo by Melissa McMasters from Memphis, TN, United States, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0&gt;, via Wikimedia Commons.

Red-breasted Nuthatches travel in mixed flocks with Black-capped Chickadees (Poecile atricapillus), Downy Woodpeckers (Picoides pubescens), and Golden-crowned Kinglets. Unlike the larger, resident White-breasted Nuthatch (Sitta carolinensis), the Red-breasted Nuthatch has a reddish belly and black eye stripe. Its call is more nasal and higher pitched. Both species are called “upside-down birds,” as they often walk down a tree’s bark hunting for insects. They will take sunflower seeds, peanuts, and suet at feeders.

Next time you see a bird looking for food by walking upside down on a tree trunk, look to see if it has a reddish belly and black stripe through its eye. you may have spotted the less common Red-breasted Nuthatch (Sitta canadensis). Photo by Wolfgang Wander, CC BY-SA 3.0 <http://creativecommons.org/licenses/by-sa/3.0/&gt;, via Wikimedia Commons.

Pine Siskins are very gregarious and often travel and feed in flocks. This brown, streaked bird with yellow on the edges of its wings and tail is better identified by its harsh, ascending “zrweeet” call. If they are around, you will see them at thistle feeders.

Pine siskins (Spinus pinus) are rather non-descript, brown and white striped birds with a touch of yellow on their outer wings and tails. They usually travel in flocks and can suddenly arrive at feeders. Photo by dfaulder, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0&gt;, via Wikimedia Commons.

Not every Blue Jay (Cyanocitta cristata) that you will see this winter is a permanent resident here. About a quarter of Blue Jays are migrants from northern climes. At this time of year, I often see them flying over highways as they migrate.

Blue Jays (Cyanocitta cristata) are often taken for granted but they really are a beautiful bird. The birds you see in the fall and winter here might have migrated here from the north. Photo by Mdf, CC BY-SA 3.0 http://creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons.

It’s a great time of year to observe these colorful visitors from the north. Put out a bird feeder or two and enjoy them.

They Get Around

If you’ve ever had to remove burrs from your pants after a hike or from your dog’s ear after a walk, you know what I’m talking about. The different ways plants have evolved for dispersing their fruits and seeds are truly remarkable. All for the sake of reproducing their species, seeds are adapted in different ways to travel by land, air, and sea—and in some cases, to even launch themselves on their own incredible journey through the digestive tracts of birds and other animals.

There are several ways seeds are dispersed: by hitchhiking on fur or clothing; by becoming airborne; by exploding from pods; by being carried in water; by being digested by birds, fish, and other animals; and by being buried.

While walking along the edge of my property a few days ago, I brushed up against some plants and found several “hitchhikers” attached to my jeans. They were Stick-tights (Desmodium cuspidatum). Their small, flat, green triangular seeds, which have tiny hooks that attach to the fur of many mammals, eventually find a new place to germinate. Devil’s Beggar-ticks (Bidens frondosa), with its two-pronged hooks, is another hitchhiker.

Stick-Tights seeds (Desmodium sp.) on a sneaker. Notice the small hairs. Photo by Jud McCranie / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0).

We all have blown the ripe seeds of Dandelion (Taraxacum officinale) or thrown the ripe seeds from milkweed pods to watch them float away. A “parachute” attached to your seed can certainly spread you far. Other seeds have wings that act like whirligigs or helicopters, such as the double-winged samaras of maples (Acer spp.) that spin to get away from the parent tree and hopefully finding good ground in which to germinate. There is a seed attached to each wing.

The orchid family has the world’s smallest seeds. Seeds such as these from Vanilla (Vanilla planifolia) don’t have an endosperm with food reserves so they need to disperse in the air and reach soil that contains fungi, which supply resources for germination and growth. Fingers and photo by Patrick Sweeney.

Researchers have documented incredible long-distance dispersals of plants and fungi on the feathers of birds. Microscopic spores of mosses, liverworts, and fungi have been found on the primary feathers of three bird species: Semi-palmated Plover (Charadrius semipalmatus), Red Phalarope (Phalaropus fulicarius), and American Golden-Plover (Pluvialis dominica). These birds migrate from the Arctic to South America. Those spores were still alive when the birds arrived at their destinations. When the birds molt their feathers the spores contact the ground and germinate.

Native to Connecticut, Jewelweed, also called Touch-Me-Not (Impatiens capensis), has a more explosive tendency. As the fruits dry out, mechanical energy stored in valves in the fruits cause them to coil inward, collapse the fruit pods, and eject the seeds. If you touch the slender seed pods, which are ripe now, you will see the seeds explode out of the pods, sometimes traveling up to 8 feet (2.5 meters) or more. Jewelweed spreads easily as a result. And it’s a good thing, because the flowers are an important source of nectar for migrating hummingbirds. The ripe white berries of dwarf mistletoes (Arceuthobium spp.), native to the western United States and Canada, also explode, ejecting seeds at an average speed of 60 miles (96.5 kilometers) per hour and scattering them as far as 50 feet (about 15 meters). The Eastern Mistletoe (Phoradendron leucarpum), native to southern North America is not nearly so dramatic. Its seeds are dispersed when birds eat its fruit, leave seeds in droppings and also wipe the sticky seeds from their bills on tree branches, where they can germinate.

The seed of the Coconut Palm (Cocos nucifera) can float in saltwater for up to a year before seeding itself on a southern sandy shore. The “seeds” of the Red Mangrove (Rhizophora mangle) actually germinate and become seedling propagules before dropping off the parent tree. They are dispersed by water and eventually embed themselves in the shallows.

Patrick Sweeney, Senior Collections Manager for Botany at the Yale Peabody Museum, is holding a Double Coconut or Coco de Mer (Lodoicea maldivica) the world’s largest seed. There are various theories as to why the seed evolved to be so large. The giant seeds drop near the parent and have the food resources to grow in the shade and develop a long petiole to reach light. Photo by Larry Gall.

There is a well-known relationship between the Yellow-rumped Warbler (Dendroica petechia) and the flowering shrub Small Bayberry or Wax Myrtle (Morella caroliniensis). When these warblers eat these berries, the birds’ gizzards scarify the seeds and their droppings help to fertilize them, ensuring germination. These birds were once called Myrtle Warblers.

Besides eating the blue, berry-like cones of the Eastern Red-Cedar (Juniperus virginiana), Cedar Waxwings (Bombycilla cerdrorum) love to eat the red berries of Mountain-Ash (Sorbus sp.), thereby spreading the tree’s seeds. Photo by Mike’s Birds from Riverside, CA, US / CC BY-SA (https://creativecommons.org/licenses/by-sa/2.0).

Other seeds such as acorns rely on animals like squirrels, chipmunks, and even crows to bury them. If the animal does not return to its stash, the seeds may germinate. To attract wildlife, plants like blackberries and raspberries surround their seeds with a brightly colored and sweet tasting pulp. Even ants get into the act. The seeds of the spring wildflower Bloodroot (Sanguinaria canadensis) have elaiosomes, fatty attachments that attract ants. The ants will carry seeds to their nest and eat the elaiosomes. The seeds then have a fertile place to germinate.

Seed of Jeffersonia diphylla (Twinleaf; Berberidaceae) with a white or yellowish appendage called an elaiosome. This fat body attracts ants, which carry the seed to their nest. Seed dispersal by ants is known as myrmecochory. Photo by Hans Stuessi / CC BY (https://creativecommons.org/licenses/by/4.0).

Why do these seed dispersal adaptations exist? There are several reasons. Often, the survival rate of a seed improves away from the parent plant, because it competes less with the parent and, in cases where predators are attracted to a clump of newly germinated plants clustered around a parent plant, it is less likely to be eaten. These adaptations allow plants to reach specific habitats that are more favorable for survival, a hypothesis known as directed dispersal. Adaptations that favor dispersal on a more distant scale allow plants to colonize new and vacant habitats or regions, reducing a plant’s risk of predation and increasing its chances for survival.

So, the next time you spy a Jewelweed “popper” go ahead, give it a pinch and watch those seeds fly! You’ll be helping seeds do what they were meant to do—and besides, it’s fun.

Hawk Heaven

Look up! It’s happening right now, right over your head. It’s the autumnal migration of raptors—hawks in particular. And it is one of nature’s most impressive animal migrations.

When I was a child, I asked my mom to take me to Hawk Mountain. It was a two-hour drive from where we lived in northern New Jersey to Kempton, Pennsylvania, but she was determined to help fuel my passion for nature and off we went. It was a sunny early November day when we arrived at the North Lookout. Just as we got there a Golden Eagle (Aquila chrysaetos) flew by us at eye level. The sun lit its seven foot wingspan as if it was on fire. I’ve been hooked on hawks ever since. Every year I watch for them as they pass through our area.

Cooper’s Hawks (Accipiter cooperii) are in a group of hawks called accipiters. Their short, rounded wings and long tails are adaptations for darting through forests and catching birds, their primary prey. Cooper’s hawks can be told from similar Sharp-shinned hawks (Accipiter striatus) by having a larger head and a longer, round-tipped tail. Photo by Dominic Sherony / CC BY-SA (https://creativecommons.org/licenses/by-sa/2.0).

Hawks, falcons, ospreys and vultures can be seen migrating here from the end of August through mid-December, although the greatest diversity of species can be seen now through the end of the month. The birds take advantage of warm, spiraling air currents called thermals, which allow them to rise thousands of feet. They “hop scotch” south, gliding from one thermal to the next. There are two migration paths or flyways these raptors tend to follow in Connecticut. They catch updrafts and thermals along the Northwest Hills and use thermals to follow the coastline. Some Ospreys (Pandion haliaetus) and Peregrine Falcons (Falco peregrinus) bypass the land routes south and fly across the Atlantic instead. These birds are heading to the northern South American coast.

Ospreys can be told from other hawks in flight by having “crooked” wings and dark “wrists.” The majority of ospreys fly through our area earlier in the migration, mostly during September. Photo by U. S. Fish and Wildlife Service – Northeast Region / Public domain.

Weather can really influence raptor flight on any given day. The best conditions occur on certain kinds of days, such as after a cold front passes through, and on days with northwesterly winds. On a windy day they fly from dawn to dusk.

Red-shouldered hawks (Buteo linneatus) are in a group of hawks called buteos. Their wide, rounded wings and fan-shaped tails are great adaptations for soaring. Red-shouldered hawks can be told in flight from larger Red-tailed Hawks (Buteo jamaicensis) by their quicker, choppier wing beats and translucent, white, crescent-shaped patches on the primary feathers, seen here on the left wing of this bird. Photo by Andy Morffew from Itchen Abbas, Hampshire, UK / CC BY (https://creativecommons.org/licenses/by/2.0).

Although in good conditions you might see hawks overhead anywhere, there are some great viewing hotspots in Connecticut. One of the best is Lighthouse Point Park in New Haven. Quaker Ridge Hawk Watch at Greenwich Audubon is another great site. Other places to watch are included here.

Many of North America’s fall raptor migratory routes converge at Veracruz, Mexico. There a small section of coastal plain is constricted between the mountains of the Sierra Madre and the Gulf of Mexico. At two raptor watching sites counts can top 100,000 birds in one day! It is the greatest raptor flyway in the world.

There are various tricks to identifying hawks, falcons, ospreys, and vultures in flight. The Cornell Laboratory of Ornithology’s All About Birds is a great site for identification. To test your knowledge, you can try a quiz.

Now’s the time to see this amazing wildlife spectacle. The next time a cold front passes through or winds blow from the northwest, grab your binoculars and look up.

Autumn Colors Were Already There, Mostly

They’re changing now.

It’s that time here in Connecticut when deciduous trees change color and add drama to our forests and landscapes. Most of the colors we see in beautiful autumn foliage have been there all along. As day length and temperature decrease, the cells between the leaf and the petiole (stem) develop a corky abscission (separation) layer that begins to block materials coming into and going out of the leaf. As a result, leaves stop making new chlorophyll (the green pigment that makes energy for the plant using sunlight, carbon dioxide, and water) and their green color fades. The leaf’s yellow and orange pigments, called carotenoids, then show through. Yellow leaves from trees such as Witch Hazel (Hamamelis virginiana) are a good example.

Sweet Pepperbush’s (Clethra alnifolia) bright yellow leaves are caused by the carotenoid pigment called xanthophyll. This color was masked during the summer by the green chlorophyll. Photo by Andy Brand.

Some pigments are produced later by chemical changes and weren’t there all along. Anthocyanins give rise to the brilliant reds in the Sugar Maple (Acer saccharum), Sumac (Rhus spp.), and Northern Red Oak (Quercus rubra) and to the red-purplish color in Flowering Dogwood (Benthamidia florida).

The intense red, fall foliage of the Sugar Maple is caused by the pigment anthocyanin. Photo by Sarah Bailey

Weather certainly affects the intensity of colors. The drought we have been experiencing has stressed our trees. Some lost their leaves early or started turning color prematurely. So fall foliage will not be as vibrant. Adequate summer rains promote healthy trees that hold onto their leaves longer and thereby have richer autumn colors.

The right fall weather can cause anthocyanins to produce vibrant reds. This pigment needs sunlight for color production and the colors are enhanced by sunny days and cool nights. This is why fall color is so outstanding in the colder climes of Vermont and other areas of northern New England.

Owen Reiser, a biology and mathematics student from Southern Illinois University, filmed leaf color changes using time-lapse photography.

The purpose of leaf color is still shrouded in mystery, especially for the anthocyanins. Researchers have proposed various hypotheses. A physiological explanation is that anthocyanins act like a sunscreen, allowing the tree to better reabsorb nitrogen as chlorophyll is broken down. Nitrogen helps the plant in the next growing season. There is evidence is that redder leaves have less nitrogen when they fall from the trees, compared with leaves without anthocyanins.

The fall foliage of some kinds of plants is consistent every year. Leaves of the Oak-leaved Hydrangea (Hydrangea quercifolia) are usually maroon. Photo by Adam Wheeler, Broken Arrow Nursery.

One biological explanation is that color is camouflage for leaves to keep them from being recognized and eaten. Or the bright leaf colors may be an adaptation to dissuade insects from laying eggs if they think the leaves are toxic, thereby minimizing damage to the plant the following year. Another possible explanation is that bright colors are a flag to draw animals to eat the fruit and so disperse seeds away from the tree. Poison Ivy (Toxicodendron radicans) is thought to be an example of this—its bright red leaves in the fall may be a signal to birds that the plant’s white berries are ripe.

The red leaves of Poison Ivy'(Toxicodendron radicans) may be a signal to birds that its white berries are ripe and ready to eat. Photo by Famartin / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0).

Rather than raking, bagging, and putting your leaves to the curb, put them to good use. Remember that leaves make an outstanding mulch under your trees and shrubs and create important overwintering sites for native moths that provide food for birds for next year’s nesting season. You can easily make a leaf mulch container by a bending a four-foot (1.2 meter) high section of hardware cloth into a large circle supported with two stakes. Fill it with your leaves and by next summer or fall you’ll have an excellent mulch to add to your garden beds through the growing season.

Happy leaf peeping.

Plant Extra Parsley Next Spring

Last week I found some late stage, or instar, Black Swallowtail caterpillars on my parsley plants. I couldn’t believe that I missed seeing them earlier. If you have sunny, meadow-like areas nearby, as well as gardens with flowering perennials, there a good chance you’ll see them, as these are the larvae of the most common swallowtail butterfly in the United States. I’ve seen Black Swallowtails laying eggs on my Fennel (Foeniculum vulgare) and they may have laid eggs on my Parsley (Petroselenium crispum) too. Or I might have brought home these larvae on parsley I purchased from the nursery.

Black swallowtail larvae go through five instars or stages. Here is a fifth instar forming the characteristic “J'” shape which is just before changing into a chrysalis. Notice the yellow spots on a greenish background compared to the Monarch butterfly larva below. Photo by (c)2009 Derek Ramsey (Ram-Man) / GFDL 1.2 (http://www.gnu.org/licenses/old-licenses/fdl-1.2.html)
Monarch larvae have yellow, black and white stripes. Photo by USFWSmidwest / Public domain.

I put my pots of parsley with the caterpillars under a screened laundry basket to protect them from parasitic flies. Each one has now transformed into a grey pupa, or chrysalis, and will spend the winter there. I will release the butterflies in the spring after they eclose, or hatch into adults.

The Black Swallowtail’s second generation spends the winter as a pupa or chrysalis and will hatch in the spring. This one is attached to a screen laundry basket. Photo by the author.

Both fennel and parsley are members of the carrot family (Apiaceae). Black Swallowtails also lay eggs on other members of this plant family, including Queen Anne’s Lace (Daucus carota) and Dill (Anethum graveolens). The larvae also feed on some members of the Rutaceae, or citrus family, such as Common Rue (Ruta graveolens). I find it interesting that some companies push insecticides to kill the “parsley worm” in the garden. Insecticides have no place in a wildlife garden for native bees and butterflies (not to mention on herbs that you plan to eat). Many homeowners are not aware of what a beautiful butterfly this larva will become. That’s why I say plant a little extra parsley for the Black Swallowtails.

Before other plants from this family were introduced in the United States for gardens, the traditional larval food plant in the region for swallowtails probably included two species of the Connecticut native perennial Golden Alexanders, including Common Golden Alexanders (Zizia aurea) and Heart-leaved Golden Alexanders (Zizia aptera).

Common Golden Alexanders is typically found in floodplains, meadows ,and on the shores of rivers and lakes. But Heart-leaved Golden Alexanders is rare in New England and is a state-listed endangered species in Connecticut. It loves calcium-rich, or calcareous, soils and in Connecticut has been found growing on precolonial Native American shell middens, which are piles of leftover oysters, mussels, and clams.

Common Golden Alexanders (Zizia aurea) is a larval host plant for Black Swallowtails in the wild. Photo by
(c)2007 Derek Ramsey (Ram-Man) / GFDL 1.2 (http://www.gnu.org/licenses/old-licenses/fdl-1.2.html).

Black Swallowtails usually have two generations per year. After spending the winter as a chrysalis, the first generation hatches between late April and early June. The egg stage lasts four to nine days, the larval stage 10 to 30 days, and the pupal stage 9 to 18 days (in the first generation). 

A Black Swallowtail caterpillar begins life with all the unappealing appearance of bird poop—all black with a white stripe across its midsection. Many butterfly larvae have early life stages that mimic bird droppings as a protection from predators. There is also mimicry in the adults. The color of the adult Black Swallowtail mimics the coloration of the Pipevine Swallowtail (Battus philenor), a toxic species, and therefore the Black Swallowtail gains some protection from bird predation.

The first two Black Swallowtail instars mimic bird droppings to keep from getting eaten by predators. Photo by Jacy Lucier / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0).

Adult Black Swallowtails will come to a host of plants to find nectar, including native perennials such as Meadow Phlox (Phlox paniculata), Wild Bergamot (Monarda fistulosa), milkweeds such as Butterfly Weed (Asclepias tuberosa) and Swamp Milkweed (Asclepias incarnata), and annuals such as Zinnia and Cosmos.

Black Swallowtail males have rows of large yellow spots on the upper wings. Notice the fake “eyes” on the hind wings, which can direct a bird’s bite there instead of the head. Photo by D. Gordon E. Robertson / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0).
Black Swallowtail females have smaller rows of yellow spots and much more blue on the hind wings. Photo by Kenneth Dwain Harrelson / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0).

Adult male butterflies can use lek mating, in which a bunch of males will wait near larval food plants for females and display there for them.

Through natural succession, many of Connecticut’s habitats eventually change over time and become mature forests. Meadows, however, provide key habitats for a host of species, including Black Swallowtails. You can add to or create your own mini-meadow in a perennial garden bed in your yard or neighborhood by planting Golden Alexanders and adding some parsley, dill, or fennel in the summer. Plant it and they will come.

Oaks Are Mighty

Planting an oak tree in your yard can do more for wildlife than a perennial border of native plants.

Oaks are a keystone species. They profoundly influence other species in our forests. North American oaks provide food and shelter for more species than any other tree group and form the backbone of many different forest communities. Here in Connecticut, there are 470 species of Lepidoptera (butterflies and moths) whose larvae eat oak leaves.

This Funerary Dagger Moth larva (Acronicta funeralis) is just one of the 470 species that feed on oaks.

Having a bunch of larvae, or caterpillars, eating the leaves of your oak tree may not appeal to you, but if you are a bird, it certainly would! More than 90% of forest-nesting birds feed butterfly and moth larvae to their young. The woods across from our house are filled with Northern Red Oak (Quercus rubra) and White Oak (Quercus alba) trees. In early May, these trees are loaded with neotropical birds like warblers, whose migration is perfectly timed with the larval hatch.

The Charter Oak, oil on canvas, Charles De Wolf Brownell, 1857, Public Domain. Wadsworth Athenaeum.

The Charter Oak was a very large White Oak which grew on Wyllys Hyll in Hartford. It may have dated back to as early as the 12th century but succumbed to a wind storm on August 21, 1856. Legend has it that Connecticut’s Royal Charter of 1662 was hidden in a hollow of the tree to keep it from being confiscated by the English governor-general. This symbol of American independence is commemorated today on the Connecticut State quarter.

Acorns are falling from trees now. This year doesn’t seem to be a mast year. In a mast year, which happens every few years, oaks produce far more acorns. This could be because larger numbers of acorns might overwhelm predators and ensure more acorns germinate and survive.

Northern Red Oak leaves have pointed lobes and rounded acorns with a cap which looks like a fedora. Photo by Dcrjsr / CC BY (https://creativecommons.org/licenses/by/3.0).

White Oak acorns germinate immediately on falling into the leaf litter, whereas Northern Red Oak acorns need a cool, moist period and won’t sprout until the spring.

White Oak leaves have rounded lobes and oblong acorns with caps which extend lower than red oak acorns, like ski hats. Photo by Alouis21 / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0).

Did you ever wonder why there are more red oaks than white oaks? You can thank an Eastern Gray Squirrel (Sciurus carolinensis). Acorns from the Northern Red Oak have more tannin, a bitter chemical that protects the acorns from insects and other predators. White Oak acorns have less tannin and so are “sweeter.” Peter Smallwood, associate professor of biology at the University of Virginia, and Michael Steele, professor of biology at Wilkes University, have found that squirrels eat 85% of white oak acorns shortly after finding them, but store about 60% of the acorns of red oaks. 

This Eastern Gray Squirrel is eating the sweeter White Oak acorn and not bothering to bury it for later. Photo by Paul Johnston / CC BY (https://creativecommons.org/licenses/by/3.0).

Gray squirrels bury acorns in different places, which is called scatter hoarding. It is thought that they use both their memory and landmarks to find their caches. When a squirrel grabs an acorn, it often does a quick head flick and turns the nut several times in its paws and mouth. These behaviors help the squirrel determine the nut’s freshness and weight, as lighter acorns are often infested with acorn weevils. But, as we know, squirrels don’t remember where all their acorns are, so we can thank them for planting new trees.

Oaks need our help. Some stands of oaks have been hit hard by invasive species. There have been major Gypsy Moth (Lymantria dispar) infestations in the last few years, particularly in eastern Connecticut. Oak wilt is a vascular plant disease caused by the fungus Bretziella fagacearum. This fungus grows on the outer sapwood and restricts the flow of water and nutrients through the tree. It has infected many oaks in the eastern United States, particularly the red oak group, and has been recently confirmed in eastern New York, including on Long Island. To help control the spread of oak wilt, please don’t move firewood long distances.

If you are thinking of planting a tree, consider planting an oak. Your grandchildren will enjoy its shade and the wildlife around it will flourish. Although oaks take a long time to mature, they have an average growth rate when young. As philosopher and author Matshona Dhliwayo says, “an oak tree is a daily reminder that great things often have small beginnings.”

Recalling Charlotte

Malevolent, scheming, horrid, wretched, malignant, hideous, and nasty. When you google words for spiders, these are what come up. Spiders need a good PR firm.

I find the distain for spiders interesting, given that one of the most beloved children’s books of the past two generations is E.B. White’s Charlotte’s Web. This could be a learned behavior. White wrote:“I think it is too bad that children are corrupted by their elders in this hate campaign. Spiders are skillful, amusing, and useful, and only in rare instances has anyone come to grief because of a spider.”

Now is the time of year when we often see orb-weaver spiders of the family Araneidae, the third largest of the spider clan. The Barn Spider (Araneus cavaticus) likes to build webs around human structures. This is the species White noticed in his barn in Maine and whose egg case he brought back to his apartment in New York City.

The spider E.B. White wrote about in Charlotte’s Web is based on the Barn Spider (Araneus cavaticus). Photo by Kilarin / CC BY (https://creativecommons.org/licenses/by/2.0)

The Black and Yellow Argiope or Yellow Garden Spider (Argiope aurantia) is a common and sizeable orb weaver often seen in meadows. Although large, it is not aggressive and will only bite if grabbed or stepped on. Its bite is like a bee sting. Once mated, the female Argiope produces a ball-shaped egg sac that is up to an inch (2.5 centimeters) in diameter. She’ll guard her eggs on her web as long as she can through the fall, when she’ll die. Come spring up to 1,000 spiderlings will hatch. They will spin a long strand of silk that catches in the wind and so disperse. This is called ballooning and spiderlings have been known to be taken into the jet stream. They have been detected by weather balloons collecting air samples at 16,000 feet (5 kilometers)!

The Black and Yellow Argiope or Yellow Garden Spider (Argiope aurantia) is frequently seen in meadows. Photo by Judy Gallagher / CC BY (https://creativecommons.org/licenses/by/2.0)

When people think of spider webs, they usually have in mind webs from orb weavers. Each evening these spiders consume their old web, then make a fresh one by spinning a strand of silk that floats to a nearby shrub or other surface. The spiders drop a line from the center, making a “Y,” then create “spokes” of plain silk and concentric rings of sticky silk. The non-sticky spokes let them travel around their web more quickly to subdue prey. Try touching the spokes and rings sometime to feel the difference.

An orb web from the family Araneidae. The radiating “spokes” are not sticky and let the spider travel quickly to secure prey. The concentric circles are sticky and catch prey. Photo by Beatriz Moisset / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0).

Spider silk has extremely strong tensile strength, comparable to steel. We humans have put that strength to use in many ways. Spider silk has been used as crosshairs in telescopes, microscopes, and telescopic rifle sights. Different methods of producing spider silk, such as combining with silk from silkworm moths, has created such products as ballistics armor, athletic footwear, personal care products, breast implant and catheter coatings, insulin pumps, and outerwear.

When an insect flies into a web, orb weaver spiders bite their prey, inject venom, then use silk to wrap the prey. They also spin a zigzag pattern of silk, called a stabilimentum, in the center of the web. There is debate about the purpose of this. Possibly it’s meant to warn birds away from the web, as a lure for prey, or to decrease the visibility of the web to insects, making it harder for prey to avoid the web.

The stabilimentum is a zig-zag patterned part of the web; there are different theories as to its purpose. Photo by Rhododendrites / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0).

Orb weavers and other spiders are important in ecosystems. They not only prey on species we consider to be garden pests, but in turn they are food for many other species. For example, much of the diet of Ruby-throated Hummingbirds (Archilochus colubris) includes spiders. Ruby-throats use spider silk to weave lichen into their nests.

Give spiders a chance—they are amazing creatures. And as my wife will avow—anything that eats mosquitoes is OK.