Archives For Birding

The elegant flight and bright white plumage of the great egret (Ardea alba) belie its harsh croak when it takes off from a marsh. It was this bird’s beauty that nearly led to its demise at the turn of the twentieth century, when these and other waders were hunted for their feathery plumes that women wore in their hats.

Since then, the great egret, standing more than 3 feet tall with a nearly 5-foot wing span, has become the symbol for the National Audubon Society, founded in part to stop these birds from being killed to extinction.

Great egrets spend winter as far south as the West Indies, Central America, and South America. In spring, they migrate in small flocks during the day, eventually choosing a place farther north to raise young in nests close to trees and shrubs called colonies, often with other large waders including the great blue heron.

PHOTO: Great egret (Ardea alba).

A great egret (Ardea alba) fishes; in the background is a great blue heron. Photo © Carol Freeman

During breeding season, a patch of skin on the bird’s face turns green, contrasting with the bright yellow bill. Males perform fancy courtship displays, opening up and fluffing their white plumes that grow to extend beyond their backs.

Both male and female build a platform-style nest of sticks in a tree or shrub often toward the top and above or near water. The female lays three to four greenish-blue eggs and gets help from her mate during incubation. 

When the young hatch in about 24 days, the nestlings begin their incessant croaking—getting louder as they grow older—and beg for regurgitated food from their parents.

PHOTO: Great egret (Ardea alba).

A great egret in flight over the lagoons. Photo © Carol Freeman

The great egret mostly eats fish, but it also dines on frogs, snakes, and aquatic insects such as dragonflies, and even grasshoppers and rodents in fields near their nesting territories.

The egret wades slowly through the water up to its belly looking for prey. Suddenly, it will stop and stand still, its motionless legs likely looking like branches to a fish, which will come closer, and then get snatched up by the hungry wader. The bird swallows the prey head first, sometimes having to flip it up in the air and catch it so it will be in the right direction to go down smoothly.

Come late summer and autumn, great egrets gather in loose feeding flocks, sometimes creating a sea of white in a wetland and a stunning spectacle for observers.

PHOTO: Great egret (Ardea alba).

A great egret wades in the Skokie Lagoons. Photo © Carol Freeman

Once on the state endangered species list, the great egret is doing well in Illinois; however, habitat loss and water pollution may threaten its future. Visit Baker’s Lake in Barrington to watch the great egret during breeding season and McGinnis Slough in Palos Park late summer to watch large feeding flocks as they head south for the winter.

The great egret is the June bird species highlighted by the Forest Preserves of Cook County. Come #birdthepreserves with the FPDCC; view the list of upcoming events for free events near you.


©2016 Chicago Botanic Garden and my.chicagobotanic.org

“Baltimore oriole,” my husband Chuck called out—and there it was, its orange coloring glowing so brightly in the morning sun that it seemed lit from within. The bird almost seemed to be posing for us, perching in full view on a nearby tree branch and bobbing its black head as it sang.

Al Stokie, our expert birding companion, recorded it in his notebook; it would become part of the weekly bird survey he supplies to the Chicago Botanic Garden.

We continued on our walk through a wonder of the natural world that anyone in the Chicago area can see for the price of a pair of binoculars: spring bird migration.

Every spring, small, colorful warblers fly through the Chicago area on their way from their winter homes in Central and South America to their nesting grounds in the northern United States, Canada, and as far north as the Arctic Circle. And every year, birders at the Garden and beyond delight in the sight.

“In May, you always go crazy,” said Stokie, who has become the official compiler of the Garden’s bird statistics.

Cape may warbler.

Cape May warbler

Blackburnian warbler.

Blackburnian warbler

But May isn’t just for experienced birders; the birds are so numerous and their breeding plumage so gorgeous that it’s a perfect time for anyone to explore bird-watching. The 385 acres of the Garden are an excellent place to start. “The Garden is a pretty well-known spot for birding,” said Jim Steffen, the senior ecologist who oversees the Garden’s bird-friendly practices and its cumulative bird list, which currently numbers 255 species.

Come #birdthepreserves with the Forest Preserves of Cook County. View the list of upcoming events for free events near you.

FPDCC Bird of the Month chart.

Learn about the bird of the month at birding events at your local forest preserves.

And this year, the Garden is partnering with the Forest Preserves of Cook County’s #birdthepreserves initiative. There are events at the preserves, and a different bird is featured each month. (In May, it’s the Baltimore oriole.) There’s even a good-natured competition to see which site can record the most bird species. 

Where to look for birds at the Garden? It depends.

“You bird the Garden at different times of the year in different places,” Stokie said. “May is warbler month, and warblers are found in the woods.” So he started us off in the McDonald Woods, in the Garden’s northeast corner. We walked along the wood-chipped path, and on boardwalks and bridges over streams and ephemeral ponds, watching for movement in the trees. It was a blustery morning. “Our problem today is going to be the wind,” Stokie said, and he was right. We saw blue-gray gnatcatchers, catbirds, ovenbirds, and that beautiful oriole. And when we got to a small forest pond, we saw a solitary sandpiper scurrying through the water on its stick-like legs.

Stokie saw far more than I did—he recorded 48 species—but we didn’t get the full-on spring migration blast of birds.

You might, though.

The peak of spring migration is typically May 10 – 20, and International Migratory Bird Day is May 14. Most of the warblers will still be moving through in the next few weeks, Steffen said, and there should be flycatchers, goldfinches, woodpeckers, and orioles. Around the Garden Lakes, he said, people can see wood ducks, mallards, night herons, green herons, and great blue herons.

Great blue heron.

Great blue heron

Ruby-crowned kinglet.

Ruby-crowned kinglet

It’s a grand sight. But along with the beauty, Steffen sees cause for concern due to climate change. Trees are leafing out earlier, before the warblers—cued by the lengthening of days—arrive. “The buds are already open, and the insects associated with them are gone,” Steffen said. “It’s messing up the synchronization.”

The best places to see birds at the Garden in spring, Stokie says, depend on the bird. Warblers and vireos will be in woodlands like the McDonald Woods and the Barbara Brown Nature Reserve at the Garden’s southeast corner. Sparrows will be in open areas like the Dixon Prairie; and shorebirds and late migrating ducks will be found in the wet areas just north of Dundee Road.

Hairy woodpecker.

Hairy woodpecker

Sign up for a bird walk with an expert. The Garden will have a spring migration walk on May 21. 

Or go to any forest preserve or park. Look for people with binoculars, and ask what they’re seeing. You’ll be off and birding.


©2016 Chicago Botanic Garden and my.chicagobotanic.org

In early May, when the leaves of maples are unfolding into a soft green, the Baltimore oriole (Icterus galbula) returns, giving his liquid “tea-dear-dear” song in suburban yards and forest preserve edges.

Homeowners who put oranges and grape jelly in feeders are often rewarded with a look at the male with his black head and back contrasting with his brilliant orange breast as he eats a spring meal.

PHOTO: A male Baltimore oriole sits amid the grapevines.

A male Baltimore oriole sits amid the grapevines. Photo © Carol Freeman

Later, the female, with a dusky-colored head and yellowish-orange breast, will come. If she sees some 12-inch-long soft strings of light-colored yarn put out by humans, she may snatch them to make her nest. A common breeding bird of open woodlands, natural spaces, gardens, and parklands, the oriole has returned from its winter in the South: Florida, the Caribbean islands, southern Mexico, Central America, and northern South America.

PHOTO: A female Baltimore oriole enjoys nectar from an apple blossom in the spring.

A female Baltimore oriole enjoys nectar from an apple blossom in the spring. Photo © Carol Freeman

By May, Baltimore orioles have arrived in the eastern United States to set up breeding territories. To get her attention, the male hops around the female, spreads his wings, and bows forward. The female responds by fanning her tail, fluttering her wings, and chattering. The female weaves plant fibers including grapevine bark, grass, and other materials such as yarn (and even horsehair) to build a hanging, pendulous, pouch-like nest. Typically, orioles nest about 20 to 40 feet high at the end of a branch. Their preferred locations are on cottonwoods, American elms, and maples.

PHOTO: Baltimore oriole nest.

The Baltimore oriole nest is a labor of love. Photo © Carol Freeman

In his Life Histories of North American Birds series, Arthur Cleveland Bent noted that the oriole is “perhaps the most skillful artisan of any North American bird.” Those lucky enough to see an oriole nest will most likely agree. It can take a week to ten days for the female to complete her nest. She’ll then lay three to seven pale eggs blotched with brown, which hatch in 11 to 14 days. The young remain in the nest for another 11 to 14 days, getting fed constantly by their parents, until they’re able to hop out onto a branch, exercise their wings, and then fledge.

These colorful birds eat insects, fruit, and nectar, (and grape jelly!), and can help keep populations of pests such as gypsy moth caterpillars in check. Agile members of the blackbird family, orioles can hang upside down and walk across twigs, or fly directly from perches to grab flying insects. Besides the “tea-dear-dear” song, orioles also give a series of chatters and scolding notes, which can alert you to their presence.

As summer goes on, the orioles seem to disappear, spending most of their time feeding young and less time singing and chattering. But come mid-August to early September, the orioles start singing again—often shorter songs—before they leave for winter vacation.

Come #birdthepreserves with the Forest Preserves of Cook County; view the list of upcoming events for free events near you.


©2016 Chicago Botanic Garden and my.chicagobotanic.org

While working out in the woods this winter, a small lump on the branch of a young elm tree caught my attention. At first I thought it might be a gall, or an injury that had healed-over. On closer inspection, the lump turned out to be a ruby-throated hummingbird nest from last summer. 

Although I see hummingbirds regularly at the Chicago Botanic Garden, I rarely encounter one of their nests. Hummingbirds themselves are amazing, but their nests are truly a marvel of avian architecture. Not much larger in diameter than a quarter, they are just large enough to hold the one to three navy bean-sized eggs of the hummer. For the pint-sized bird to be able to keep the tiny eggs warm during incubation requires that the nest be not much larger than her body. 

PHOTO: Hummingbird nest and quarter (for scale).

Not much larger than a quarter, the ruby-throated hummingbird nest is an engineering marvel.

This is all well and good until the eggs hatch. Growing young hummingbirds can double or triple the amount of room necessary to hold the family. One of the ways the hummingbirds get around this need for flexibility is that they construct the nest of soft plant fibers and then wrap the whole thing with spiderweb silk. This creates an elastic nest that has the ability to expand as the contents of the nest increases. Can you imagine yourself going out and plucking a strand of sticky silk from a spider web with your fingers and then trying to use it to build something out of lightweight fuzzy plant fibers? I imagine you might find yourself wrapped up in a ball like some sort of oversized grotesque moth cocoon. The silk also helps to anchor the nest to the top surface of a horizontal branch.

PHOTO: Spiderweb silk is used by hummingbirds as a nest liner.

Spiderweb silk: the expandable nest liner preferred by hummingbirds.

Keeping the nest just the right size as the need arises helps to keep the growing youngsters warm and secure. In the western states where several species of hummingbirds nest, often at higher elevations, it is not only important to keep the nestlings warm, but also the incubating female, especially at night. Therefore, it is often the case that hummingbirds in these colder situations will locate their nests on a limb with an overhanging branch acting as a sort of roof to help block the nest from the night sky. 

Although this measure helps reduce heat loss, it is often the case that nesting females will go into a state of torpor (reduced physiological activity to lower body temperature) in order to conserve energy on particularly cold nights. This is a principle of physics in which the larger the difference in temperature between objects, the faster the heat flows from the warmer one to the cooler one. Therefore, a hummingbird with a lower body temperature will lose heat more slowly than the one with a warmer body. As I stated earlier, hummingbirds are amazing!

PHOTO: Parmelia sulcata, a common lichen, is used to help disguise the hummingbird's nest.

Parmelia sulcata, a common lichen, is used to help disguise the hummingbird’s nest.

Part of the reason—besides size—I had not noticed the nest earlier is that the birds do a fantastic job of camouflaging it. This also relates to the spiderweb silk. Some or all of the silk used is sticky. Upon completion of nest construction, the birds collect bits of lichen and attach them to the sticky strands on the outside of the nest. Interestingly, the birds seem to always use the same species of lichen, one that goes by the name of Parmelia sulcata

Parmelia sulcata is a light greenish-gray lichen with a leafy (foliose) appearance. One of our more common lichens, it is often seen on the upper branches of trees, and was particularly abundant on the ash trees that died from emerald ash borer. I don’t know if the birds chose this species of lichen in particular or, being common, it is just found most often. It is also interesting that the birds seem to apply the lichens to the nest in an upright position, with the top facing outward, so they look like they could be growing on the nest.

Come birding at the Garden! Take a birding class; join a group, and check your finds against our bird list.

Although this process is fascinating, it is not restricted to hummingbirds. One of the other breeding birds at the Garden utilizes a very similar nest construction technique to hold its three to five small eggs. The blue-gray gnatcatcher, another tiny bird (that somewhat resembles a miniature catbird in appearance and sound), also constructs a nest out of soft plant fibers, including spiderwebs, and applies lichen to the outside of its nest. A nest of this species, a little larger than that of a hummingbird, was found on a branch of one of the locust trees growing in a Garden parking lot.

PHOTO: A female ruby-throated hummingbird (males have the ruby coloring) enjoys a sip of salvia nectar in Circle Garden in summer.

A female ruby-throated hummingbird (males have the ruby coloring) enjoys a sip of salvia nectar in Circle Garden in summer.

PHOTO: A blue-gray gnatcatcher at the Garden; females look similar, but are less blue.

A blue-gray gnatcatcher at the Garden; females look similar, but are less blue.

If you’re lucky, you might find the nest of one of these birds during the nesting season, but if not, keep an eye out for little bumps, lumps, and knobs on bare branches in winter. You might get lucky.

Come #birdthepreserves with the Forest Preserves of Cook County. View our list of upcoming events for free events near you.


©2016 Chicago Botanic Garden and my.chicagobotanic.org

Look up! In partnership with Friends of the Chicago River (FOCR) and the Forest Preserves of Cook County (FPCC), an osprey nesting platform was installed on Friday, January 29, along the North Branch Trail at the south end of the Chicago Botanic Garden near Dundee Road.

MAP

The Garden’s new osprey nesting platform is located near Dundee Road and is viewable from the North Branch Trail.

The osprey is listed as an endangered species in Illinois, which means it’s at risk of disappearing as a breeding species. Fish-eating raptors that migrate south and winter from the southern United States to South America, osprey are often seen during their migrations—yet few remain in Illinois to nest. The lack of suitable nesting structures has been identified as a limiting factor to their breeding success here.

Males attract their mates to their strategically chosen nesting location in the spring. In order for a nest to be successful, it must be located near water (their diet consists exclusively of fish, with largemouth bass and perch among their favorites), the nest must be higher than any other nearby structure, and it must be resistant to predators (think raccoons) climbing the nest pole and attacking the young.

FOCR and the FPCC sought out the Garden as a partner for an installation site, in large part owing to the Garden’s strong conservation messaging and proximity to other nearby nesting platforms that have been recently installed (two are located alongside the FPCC’s Skokie Lagoons just to the south).

The Garden’s nesting platform was installed atop an 80-foot “telephone pole,” set 10 feet into the ground and extending upwards by 70 feet. The 40-inch hexagonal nest platform atop the pole has a wire mesh on the bottom so that water can pass through the sticks and stems that the osprey will bring to construct the nest.

PHOTO: Installing and osprey nesting pole.

A truck-mounted auger and crane set the nesting pole and platform into place.

PHOTO: Installing an osprey nesting pole.

The nesting platform sits atop the pole and is ideally sized for a future osprey nest; notice that we even “staged” the new osprey home with a few sticks of our own!

PHOTO: Installing an osprey nesting pole.

A metal band was wrapped near the bottom of the pole to prevent predators from being able to climb it.

PHOTO: Installing an osprey nesting pole.

The nesting pole and platform is fully installed and is visible from the North Branch Trail that runs through the Garden.

With the osprey nesting platform now in place, our hope is that within the next few years, a migrating male will select the site and pair with a female. Osprey generally mate for life, though they’re together only during the breeding and rearing seasons.

You can learn more about the how and why of the osprey nesting platform project at the FOCR website. Follow the links on that webpage for images, video, and a press release relating to the installation of an identical osprey platform at the Skokie Lagoons last spring.

Read more about the long-term effort, and about ospreys making a comeback in Cook County. Discover birding at the Garden and find our full bird list online at chicagobotanic.org/birds.


©2016 Chicago Botanic Garden and my.chicagobotanic.org