In August, when the jewelweed and cardinal flowers bloom, the ruby-throated hummingbird is migrating. It’s perfect timing, because the hummingbirds get energy for their journey southward by sipping nectar from the blossoms of these plants native to northern Illinois.
A female ruby-throated hummingbird (males have the ruby coloring) enjoys a sip of salvia nectar in the Circle Garden in summer.
The ruby-throat is the only hummingbird to breed in eastern North America, and these tiny jewels are somewhat common nesters in Cook County woodlands. They become more numerous in late summer and fall, as those that nested farther north pass through on their way to their winter homes in Mexico and Central America.
The ruby-throated hummingbird (Archilochus colubris) wears emerald green on its back and crown, and in good light, the male reveals an iridescent red throat. (During fall migration, you’ll see males as well as females and young, both of which lack the ruby throat.)
They return to Illinois in April and May, seeking nectar from early blooming trees and shrubs as well as insects and spiders.
It’s at this time you might get lucky enough to observe the courting male as he flies in a U-shape and also buzzes in front of a perched female. Buzzes? Yes! Hummingbirds aren’t silent—you can hear their wings buzz and vocalizations from their throats when they’re defending feeding territory or seeking a mate.
The female builds a thimble-sized cup nest on a horizontal branch, adding grasses and spider webs, lining it with plant down and then covering the outside with lichens and dead leaves. The young hatch in about 15 days, and remain in the nest for another 20 days or so as the female brings them insects.
An aerial wonder, the ruby-throated hummingbird, can beat its wings 53 times per second, and can fly backward and upside down.
You can attract ruby-throated hummingbirds to your yard by planting the flowers they love—tubular and brightly colored in red hues—and by putting up feeders. Hummingbirds are fun to watch at feeders as they have spats in flight trying to hoard the food to themselves.
To make hummingbird food, add ¼ cup white sugar to 1 cup boiled distilled water. Stir to dissolve, then cool before you put it into the feeder. It’s not necessary to put red food coloring in the water. Use a red feeder to attract the hummers. Hang out of direct sunlight, and clean and refill often.
Most ruby-throated hummingbirds are gone by the end of October in this area. You can put your feeders back up in April when they return.
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.
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.
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.
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.
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.
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.
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!
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.
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.
A female ruby-throated hummingbird (males have the ruby coloring) enjoys a sip of salvia nectar in Circle Garden in summer.
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.
The flowers are gone, the trees are bare, now what to photograph? Birds, of course! Winter is a great time to get some fabulous shots of winter birds. One huge bonus is that there are no leaves on the trees and the birds are much easier to see!
There are the “regular” local birds, like robins (yes, some robins do stay around all winter), goldfinches, cardinals, chickadees, mallards, Canada geese, red-tailed hawks, and cedar waxwings, to name a few. Plus, winter has the bonus of birds that actually migrate to our area just for the winter. Some migrants you will see every year are juncos, tree sparrows, and a variety of ducks. Other birds are occasional, or eruptive, and only show up once every few years, like pine siskins, red-breasted nuthatches, and redpolls. Then there are the, “wow! I’m really lucky to find this species!” birds, like crossbills, snowy owls, bald eagles, and bohemian waxwings. That is the fun part—you never know what you will find on any given day. That is why I go out every chance I get!
When you get to the Garden, some places to look are all the trees with berries! Yes, the birds love them. Another good place to look is the Dixon Prairie, where all those seeds attract a lot of birds. Be sure to check out the bird feeders at the Buehler Enabling Garden too. You can also find a variety of birds—especially woodpeckers—in the McDonald Woods. If there is open water, check there for ducks and geese. You might be surprised at just how many birds you can find in winter.
