A female ruby-throated hummingbird feeding its chick in Montgomery County.
August 20, 2017
NATURE
Jim McCormac
“Achieving gender equality requires the engagement of women and men, girls and boys. It is everyone’s responsibility.” — Ban Ki-moon
The former secretary-general of the United Nations might not think much of male hummingbirds: The boys are a disengaged group.
Of the 16 species of hummingbirds that breed in the U.S., only the ruby-throated hummingbird nests east of the Mississippi River. The speedy sprites are well-known, even to people only casually interested in birds.
The hummingbird relationship serves as a prime example of one in which the female does all the heavy lifting.
The penny-weight males return from the tropics in April, many of them having negotiated a 500-mile flight over the Gulf of Mexico. Upon their return to northern nesting grounds, the males stake a claim on suitable nesting spots.
Females return about a week later. When one enters a male’s turf, he struts his stuff. To woo his prospective mate, the male ascends as high as 50 feet, then swoops earthward like a missile, pulling up sharply at the dive’s conclusion and roaring back aloft. The U-shaped flight display is accompanied by an astonishingly loud wing buzz.
What female could resist?
If successful in wowing his girl, the male then consummates the relationship. Then he’s gone, off to cavort with flowers, roam meadows and, eventually, return to tropical haunts long before the hardworking females.
The female wastes no time starting the nest.
A ruby-throated hummingbird nest is an exquisite structure. Every time I see one, I’m amazed that the tiny, long-billed birds can construct such a home.
She begins by harvesting thistledown and other soft plant material, which is saddled to a horizontal branch using spider silk. Harvesting the silk is why hummers are sometimes seen poking around in garages and under eaves.
Eventually, she builds the nest walls into a soft cup, tied together with silk and shaped by using her body as a mold. Finally, the nest’s exterior is shingled with lichen bits for camouflage. The result is an architecturally ornate cup about 1 1/2 inches tall and 2 inches across.
Two pinky-fingernail-sized eggs are laid, and she incubates them for about two weeks. The elfin hatchlings are naked and helpless. They are born into a luxurious down-filled home, but they grow like weeds, and their bulk soon taxes the confines of the tiny shelter.
The properties of spider silk come into play by allowing the sides of the nest to bow outward yet remain strong, allowing the ever-expanding house of the hatchlings to grow to meet their needs.
All the while, the female busily gathers nectar and small insects to feed the chicks. About three weeks later, the baby hummingbirds are ready for their inaugural flight and head out into a landscape filled with summer wildflowers.
The accompanying photo depicts a nest shown to me by photographer Dean Porter, who had been tracking it and making excellent images of its progression. I’m grateful to him for sharing its location.
Naturalist Jim McCormac writes a column for The Dispatch on the first, third and fifth Sundays of the month. He also writes about nature at www.jimmccormac.blogspot.com.
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