Feasting on Green-headed Coneflower

Posted on August 20, 2014 by Mary Anne Borge

How many flowers do you see in the photo below?

Gray Hairstreak on Green-headed Coneflower (Rudbeckia laciniata)

If you said one, that’s the answer I was looking for. However, it’s not correct!

The plant pictured here is Green-headed Coneflower (Rudbeckia laciniata), also sometimes called Cut-leaf Coneflower in deference to its deeply lobed leaves. Green-headed Coneflower is a member of the Aster, or ‘Composite’ family, a name that’s pretty descriptive of their typical flower clusters (inflorescences). What our brains think is a single flower is actually a cluster (or composite) of tiny flowers, often of two different types, ray flowers and disk flowers. The petal-like parts of the flower cluster are each an individual ray flower with a single petal. In the center there are dozens of tiny tubular flowers called disk flowers, in reference to the disk-like shape of the flower cluster. In the picture above, just a few of the disk flowers are blooming.

Some Aster family members just have ray flowers, like Dandelions.

Eastern-Tailed Blue nectaring on a Dandelion

Some have just disk flowers, like New York Ironweed.

Bumble Bee on New York Ironweed

Many, like Green-headed Coneflower, have both types of flowers. When both ray flowers and disk flowers are present, the ray flowers are often sterile, in which case their primary purpose is to act as nectar guides, alerting pollinators to the availability of nectar and pollen in the many disk flowers at the center of the flower cluster.

A Silver-spotted Skipper is nectaring on the disk flowers that are in bloom on this Green-headed Coneflower. The lowest disk flowers have finished blooming, while those at the top of the flower cluster are still in bud.

The disk flowers bloom gradually over a period of a few weeks, maximizing the plant’s chances for pollination with the assistance of insect partners. In the case of Green-headed Coneflower, the disk flowers bloom gradually from the bottom, or outside ring, to the top, or center, of the flower cluster.

A Red-banded Hairstreak is drinking nectar from the last few blooming flowers of this Green-headed Coneflower inflorescence.

Because of the number and size of its disk flowers, Green-headed Coneflower is able to attract many insects as potential pollinators. Often multiple insects can be found feeding simultaneously on different flowers in the same flower cluster.

This Green-headed Coneflower offers enough flowers with nectar to feed both an American Copper and a Honey Bee.

Green-headed Coneflower’s disk flowers are large enough to accommodate small to medium sized butterflies like those pictured here. They may rub against some pollen and transfer it to another plant, assisting with pollination.

Summer Azure with Green-headed Coneflower (Rudbeckia laciniata)

Common Buckeye and Bumble Bee feeding on Green-headed Coneflower (Rudbeckia laciniata)

Beneficial predators like the thread-waisted wasps (a species of Sphecid wasp) pictured below also benefit from the abundant nectar, giving them the energy they need to reproduce. (I often see this species mating and nectaring at the same time, as they are doing here. A level of skill and coordination to which humans can only aspire!) Their anatomy makes it more likely that they will help with pollination than butterflies, since more of their bodies are likely to come in contact with pollen. The female wasps of this species (Eremnophila aureonotata) hunt caterpillars to feed their larvae.

Green-headed Coneflower with mating Wasps (Eremnophila aureonotata)

But bees are the most likely to be successful pollinators, because they are the best anatomical match for gathering pollen, and it’s more likely to stick to the branched hair on their bodies and be carried away to be deposited on another flower.

Bumble Bee and American Copper nectaring on Green-headed Coneflower (Rudbeckia laciniata)

Sweat Bee on Green-headed Coneflower (Rudbeckia laciniata)

The Sweat Bee below is gathering pollen on her hind legs to take back to feed her larvae. Only female bees gather pollen this way.

Sweat Bee (Lasioglossum species) on Green-headed Coneflower (Rudbeckia laciniata)

Dining on Green-headed Coneflower is not without danger, as this Bumble Bee found out when it fell victim to a Wheel Bug, a type of assassin bug. Sometimes the diner becomes the dinner.

Wheel Bug (Arilus cristatus) consuming a Bumble Bee smoothie

If the flowers are successfully pollinated, you’re likely to see Goldfinches and other birds feeding on the seeds later in the season and throughout fall.

Goldfinch eating Green-Headed Coneflower seeds

The Aster family is the second largest family of flowering plants in terms of its number of species, second only to the Orchid family. In late summer and fall the Aster family represents a high percentage of what’s in bloom. For information on a few other Aster family members, see Asters Yield a Treasure Trove! and Fall Allergies? Don’t Blame Goldenrod!

Resources

Eaton, Eric R.; Kauffman, Ken. Kaufman Field Guide to Insects of North America. 2007.

Elpel, Thomas J. Botany in a Day. 2006.

Indigo Buntings – Living on the Edge!

Posted on July 28, 2014 by Mary Anne Borge

As I started down the path through the meadow, I heard a ‘Chip!’ call to my left, then a ‘Chip!’ call to the right. Then another ‘Chip!’ to the left, followed by a ‘Chip!’ to the right. This call and response was repeated several times until I finally spotted the source of half of the duet, a male Indigo Bunting perched on New York Ironweed (Vernonia noveboracensis). Indigo Buntings often use this vocalization if you are near their nest, even if you are still as far away as 30-40 feet (9-12 meters).

Male Indigo Bunting perched in New York Ironweed (Vernonia noveboracensis)

Indigo Buntings need edge habitat, like an open field or meadow near a woodland, or a woods opening. They nest fairly low to the ground, usually at a height of at least 2-3 feet (.6 – .9 meters), but not more than 10 feet (3 meters) above ground. They require a dense cover of shrubs or brambles for their nesting site. The female Indigo Bunting makes the nest, weaving the structure from plant materials, including leaves, twigs, bark, and stems, possibly wrapping it with spider web, and lining it with softer grasses, mosses, rootlets, hair, down, or the fluff often attached to seeds.

Male Indigo Buntings need a high perch from which they can survey their territory and ward off encroaching competitors, which explains the need for the nearby trees. They sing to advertise their presence and ownership of their turf. The song often consists of several paired notes, sung repeatedly in rapid succession.

Male Indigo Bunting, singing

The male I saw on this visit started to sing, then flew off about 40 feet (12 meters) from his original position, continuing his song from his new grass perch. He was closer to me, and sang to draw my attention to him, presumably to distract me from seeing his partner so she could return to the nest undetected. His ploy almost worked, but I did catch a glimpse of her peeking out of a patch of blackberry brambles, about 30 feet (9 meters) away and almost out of my range of vision when I looked directly at the male.

Male Indigo Bunting

On several visits to the meadow, I caught glimpses of the female, but she was always on the move. Each time I saw her she had food in her mouth to take back to her offspring. Like most birds, Indigo Buntings require a lot of protein in their diet, especially when they are young. The meadow offers plenty of grasshoppers, caterpillars, beetles, aphids and other insects and spiders to fill that dietary need. To round out the menu, berries and seeds are made available by blackberries, goldenrods, asters and other meadow plants. There is no shortage of fresh, local, organic food available for foraging nearby!

On one visit, a female and I finally had a close encounter. She was hiding in a blackberry bramble near the trail, with an insect in her beak, as usual.

Female Indigo Bunting in Blackberry (Rubus allegheniensis) bramble

As I watched, she gradually moved to a more open spot,

Female Indigo Bunting in Blackberry (Rubus allegheniensis) bramble

stayed for a few minutes,

Female Indigo Bunting in Blackberry (Rubus allegheniensis) bramble

then disappeared into the brambles to feed the kids.

To hear an Indigo Bunting’s song, click here.

Male Indigo Bunting

Resources

Eastman, John. Birds of Forest, Yard, and Thicket. 1997.

Harrison, Hal H. Eastern Birds’ Nests. 1975

Eaton, Eric R.; Kauffman, Ken. Kaufman Field Guide to Insects of North America. 2007.

Stokes, Donald W.; Stokes, Lillian. A Guide to Bird Behavior Volume II. 1983

Bugguide.net

The Cornell Lab of Ornithology All About Birds

Gray Dogwood for Butterflies, Bees and Birds

Posted on May 23, 2014 by Mary Anne Borge

This Spring Azure butterfly is laying her eggs on the flower buds of a Gray Dogwood (Cornus racemosa), taking advantage of the nourishment this shrub provides her offspring. Dogwoods are among the favored plants of this butterfly’s caterpillars, helping to ensure that you’ll continue to see the sprightly Azure on a regular basis.

Azure butterfly laying an egg on Gray Dogwood (Cornus Racemosa) flowers

Nearby, a Red-banded Hairstreak drank the nectar offered by the profusion of lovely flowers.

Red-banded Hairstreak, different day, on Short-toothed Mountain Mint (Pycnanthemum muticum)

Blooming for a period of a few weeks in late May to mid June, Gray Dogwood is a relative of the more familiar Flowering Dogwood (Cornus florida), but Gray Dogwood is a shrub, growing to a maximum height of 12-15 feet (about 3.5-4.5 meters). The flowers and leaves of Gray Dogwood show typical characteristics of this family of plants.

Each delicate flower has four petals, arranged symmetrically in a cross shape. The leaves are opposite each other along the branches, with arched veins curving toward the tip of the leaf on both sides of the midrib. The common name, Gray Dogwood, refers to the color of the bark, which is usually a light gray. The species name, racemosa, describes the half-sphere arrangement of the creamy white flower clusters.

Gray Dogwood (Cornus racemosa)

The flowers’ nectar attracts an array of busy pollinators, including bees, beetles and butterflies. Even better, Gray Dogwood provides the female Azure butterfly a place to lay her eggs. Several moth species use the dogwoods as food plants for their caterpillars, including the beautiful Polyphemus Moth.

Birds that like to nest in the shrub layer look favorably on Gray Dogwood when they’re shopping for real estate. Northern Cardinals, Goldfinches, Catbirds and Yellow Warblers are some of the birds that covet the features offered by Gray Dogwood.

A young Gray Catbird

The multi-stemmed shrub with its sturdy branches offers a safe nesting place, with food right on the premises. During nesting season, the pollinators and any caterpillar progeny offer the protein necessary to raise healthy young birds. Newly fledged Chickadees and Titmice may also browse Gray Dogwood for a quick bite, or take refuge in its sturdy branches.

Tufted Titmouse

Flowers that are successfully pollinated by butterflies, bees or other insects will produce a round white berry-like fruit called a drupe. The fruit appears on a platform of bright red stems, called pedicels, beckoning the local bird population to stop for a meal. Birds find the fruit irresistibly delectable, eating it as soon as it ripens in late summer for a jolt of energy. Squirrels, chipmunks and other mammals also enjoy the tasty bounty.

Gray Dogwood fruit

For your viewing pleasure, the red fruit platforms remain for weeks even after the fruit is snapped up by resident and migrating birds. As fall approaches, Gray Dogwood’s leaves turn from deep green to a regal reddish-purple. In winter, its branches shelter the birds that live with us year-round.

Hermit Thrush – one of the many bird species that eat Gray Dogwood fruits

Gray Dogwood is native in the Canadian provinces of Manitoba, Ontario and Quebec, as far south in the United States as South Carolina, Kentucky, Arkansas, Nebraska, and Texas. It adapts well in many conditions. It prefers moist, well-drained soil, but can tolerate poor, compacted soils, and drought conditions. It likes sun, but it can also do well in part shade. It’s often found in woodland openings or open fields.

In landscaping, Gray Dogwood can be used alone in any location where a good-sized shrub is needed. Or even better, mixed with other species it brings visual and animal diversity to your property. Gray Dogwood combines well with Ninebark (Physocarpus opulifolius), American Hazelnut (Corylus americana), or Blackhaw Viburnum (Viburnum prunifolium), among others.

Gray Dogwood with Syrphid Fly, a Bumble Bee mimic.

Gray Dogwood is great for birds, butterflies, bees, and many other critters – even people!

Resources

Wagner, David L.; Caterpillars of Eastern North America, 2005.

Eastman, John. The Book of Forest and Thicket. 1992.

Illinois Wildflowers

Warbler Migration is in Progress!

Posted on April 29, 2014 by Mary Anne Borge

Monday was a beautiful spring day, perfect for birding at Bowman’s Hill Wildflower Preserve. The weather was sunny but cool, and probably as a result, the birds weren’t active until a bit later than we expected.

Yellow-rumped Warblers were the first and most plentiful of the migrants we spotted. They were traveling in a pack, as they usually do.

Yellow-rumped Warbler

The rump after which this bird is named

We saw Hermit Thrushes and Blue-gray Gnatcatchers, and heard, but didn’t see, a Black-throated Blue Warbler. A Pileated Woodpecker put in an appearance, too.

Pileated Woodpecker

As mid-day approached, bird activity increased. A Palm Warbler posed for us.

Palm Warbler

The bird returned to the business of foraging for food, snatching and whacking its caterpillar prey against the branch, then quickly gulping it down. Yum!

Palm Warbler with lunch, a caterpillar

Black-and-white Warblers appeared, and a Blue-headed Vireo was busy hunting for lunch, moving from branch to branch, tree to tree. A Black-throated Green Warbler peered out from the shelter of a Hemlock tree.

Black-throated Green Warbler

Then he returned to his search for food.

Black-throated Green Warbler

With wind and rain predicted for the next few days, there could be some interesting fall-outs of migrants. There aren’t many leaves on the trees yet, so viewing opportunities are maximized. Could be a good birding weekend ahead!

Spicebush or Forsythia?

Posted on April 16, 2014 by Mary Anne Borge

For the past few weeks, Spicebush (Lindera benzoin) buds looked like they couldn’t wait to open. Over the weekend when the temperatures reached 80°F in the latest round of weather whiplash, the buds burst open, resulting in a display of bright yellow starbursts lighting up the forest understory.

Spicebush (Lindera benzoin) in bloom, with ant seeking nectar

Spring temperatures have a big influence on the exact timing, but where I live in the mid-Atlantic United States, Spicebush typically blooms in late March or early April, at about the same time as forsythia. Forsythia is also lovely for the ten days or so that it’s in bloom, but then it’s a little, well, boring, when compared to Spicebush.

Sometimes called Northern Spicebush or Common Spicebush, this shrub is native in the north from Maine to Ontario, Michigan, Iowa and Kansas, then its range extends south to Texas and throughout the southeastern United States to Florida. It can generally be found in woodlands, but works well as a landscape plant, too. Spicebush gets its common name from the spicy aroma emitted from its leaves and young branches when they are rubbed or crushed.

Where Spicebush is native, it has important relationships with animals that have evolved with it over the centuries. Many insects, including early butterflies, visit the flowers for nectar, but early solitary bees and flies are the primary pollinators.

Spicebush (Lindera benzoin) with Spring Azure butterfly nectaring

The flowers bloom before the leaves unfurl, making it easy for pollinators to find them. Spicebush has male and female flowers on separate plants.

Male Spicebush flowers; note yellow pollen like little balls at tips of stamens

Female Spicebush flowers; note pistils protruding beyond the petals

So if you are using them in your landscape, you will want a male to pollinate the female plants in order to see the bright red fruits that complement this shrub’s yellow fall foliage.

Spicebush (Lindera benzoin) fall fruit and foliage

Many birds eat the fruit, but Veeries

Veery

and Wood Thrushes,

Wood Thrush

birds that are often found in the same habitat as Spicebush, are especially partial to them.

Spicebush Swallowtail butterflies are often seen nectaring on flowers in sunny locations,

Spicebush Swallowtail nectaring on Wild Bergamot (Monarda fistulosa)

but they can also be found in the woods in the vicinity of their namesake plant, Spicebush. This is because the primary food plants for Spicebush Swallowtail caterpillars are Spicebush (Lindera benzoin and in the southern U.S., also L. melissifolia) and the related Sassafras (Sassafras albidum), which is usually found in the same type of habitat. Without these plants we wouldn’t have this lovely butterfly, since its caterpillars can only survive on the leaves of a few plant species.

Female Spicebush Swallowtails lay their eggs singly on the underside of a leaf.

Spicebush Swallowtail egg

After the caterpillars hatch from the eggs, they depend on the leaves of these plants for both food and shelter. Each caterpillar eats a few leaves of a Spicebush during its development.

Spicebush Swallowtail caterpillar; notice the evidence of feeding on the leaf in the lower right corner

Looking for holes in leaves is one way to find these caterpillars. But we’re not the only creatures who have figured out this strategy for locating them. Caterpillars and other insects are an important source of food for birds, especially when the birds are raising their young. Some bird species also know enough to look for partially eaten leaves to point them to a tasty meal of caterpillar protein.

Tufted Titmouse, looking for a meal

So the caterpillars have evolved to protect themselves by destroying the evidence of their dining experience. While I watched, this caterpillar crawled to the stem of the leaf it had been eating. It chewed through the stem, and the incriminating evidence, the partially eaten leaf, fell to the ground.

Spicebush Swallowtail caterpillar, destroying the evidence of its presence by chewing through the leaf stem

Spicebush Swallowtail caterpillars have other strategies to protect themselves from predators. In their earliest growth stages they look like bird droppings, a clever disguise to deter birds from eating them. As they grow, they take on the appearance of a snake, with false eye spots above their real head. This snake disguise is an effective deterrent to at least some of the birds that might otherwise eat the caterpillars, since snakes are the birds’ predators in their wintering grounds.

Black-Throated Blue Warblers may be put off by a snake-like disguised caterpillar

When they’re not eating, Spicebush Swallowtail caterpillars hide in leaf shelters that they create for themselves by spinning silk to pull two sides of a leaf together.

Spicebush Swallowtail caterpillar using its silk to create a leaf shelter

Spicebush is also a food plant for the caterpillars of a moth called the Tulip-tree Beauty,

Tulip-tree Beauty caterpillar on Spicebush (Lindera benzoin)

and one of the giant silk moths, the Promethea Moth.

Promethea Moth Caterpillars on Spicebush

Winter is a good time to look for Spicebush Swallowtail chrysalises and Promethea Moth cocoons, since these species overwinter as pupae.

Forsythia on the other hand, primarily a native of Asia, doesn’t support any of our native insects and birds in this way. So I’m opting for Spicebush.

Spicebush (Lindera benzoin)

Resources

Butterflies and Moths of North America
http://www.butterfliesandmoths.org/

Eastman, John. The Book of Forest and Thicket. 1992.

Illinois Wildflowers http://www.illinoiswildflowers.info/trees/plants/spicebush.htm

Natural History Museum Database of Leipidoptera Hostplants
http://www.nhm.ac.uk/research-curation/research/projects/hostplants/

The Natural Web

Exploring Nature's Connections

Category Archives: Birds

Feasting on Green-headed Coneflower

Indigo Buntings – Living on the Edge!

Gray Dogwood for Butterflies, Bees and Birds

Warbler Migration is in Progress!

Spicebush or Forsythia?

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