May 15. That's the date on my 2009 phenology calendar marking the arrival of ruby-throated hummingbirds in our yard. The timing is fairly consistent from year to year, with a little variation accounted for by late-arriving winter storms that hold the migrants down south a little longer. Once in a while I'm fortunate to see a male hummer in April, three or even five weeks ahead of schedule. These precocious fellows ride the heels of yellow-bellied sapsuckers, a variety of migratory woodpecker that makes the rounds of our yard in the earliest days of spring. Sapsuckers drill wells in the bark of maple trees to access their welling sap. Small insects throng to these puddles of sticky sweetness, and hummingbirds gobble up this free source of body-warming protein to get them through the lingering chilly nights. There is always the risk of an unexpected storm or freeze. The male hummingbirds that survive the trip have a distinct advantage: early arrival in their summer range and access to a wider choice of breeding territories.
Once the females appear, I often hear chittering calls among the trees. But it takes sharp eyes and patience to see the birds firsthand. Adult ruby-throated hummingbirds seek insect prey to feed their miniscule but voracious young, making only rushed visits to the nectar feeder for their own refreshment. I stop to look for them when I first come downstairs in those still-dim minutes before sunrise, or when the evening shadows are long over the feeders.
Once the females appear, I often hear chittering calls among the trees. But it takes sharp eyes and patience to see the birds firsthand. Adult ruby-throated hummingbirds seek insect prey to feed their miniscule but voracious young, making only rushed visits to the nectar feeder for their own refreshment. I stop to look for them when I first come downstairs in those still-dim minutes before sunrise, or when the evening shadows are long over the feeders.
A female ruby-throated hummingbird ducks in to drink from the feeder, but drinks without perching--it's a fast-food operation during the nesting season.
As the fledglings become independent in late summer, everything changes. Throughout the day males, females, and juveniles zip
between feeders, flowers, perches, and hideouts. The chase always on, tiny birds whiz past us—in pursuit or retreat, and often within a mere wingspan of each other—whenever we venture into the yard. Actual fights between hummingbirds are apparently uncommon, though they seem to expend endless energy keeping each other from nectar sources.
In Birds of America, John James Audubon described this habit. “They are quarrelsome,” he wrote, “and have frequent battles in the air, especially the male birds. Should one be feeding on a flower, and another approach it, they are both immediately seen to rise in the air, twittering and twirling in a spiral manner until out of sight.”
A few years back I read an article about hummingbirds in Smithsonian magazine. The author commented how fortunate it is that hummingbirds are not as large as crows. That image has remained in my mind. The ruby-throated hummingbird’s bill accounts for one-fifth of its body length. Expand the hummer to crow-size and its bill would be more than 10 centimeters long. The pileated woodpecker provides a useful model. This bird is of comparable size to the American crow, but its bill is elongated like Pinocchio’s nose after he’s told a series of whoppers. Rather than being chisel-shaped like the woodpecker's, however, a hummingbird's bill is rapier-thin and sharp. Our Superhummer would be a Musketeer among birds. Mon dieu!
In Birds of America, John James Audubon described this habit. “They are quarrelsome,” he wrote, “and have frequent battles in the air, especially the male birds. Should one be feeding on a flower, and another approach it, they are both immediately seen to rise in the air, twittering and twirling in a spiral manner until out of sight.”
A few years back I read an article about hummingbirds in Smithsonian magazine. The author commented how fortunate it is that hummingbirds are not as large as crows. That image has remained in my mind. The ruby-throated hummingbird’s bill accounts for one-fifth of its body length. Expand the hummer to crow-size and its bill would be more than 10 centimeters long. The pileated woodpecker provides a useful model. This bird is of comparable size to the American crow, but its bill is elongated like Pinocchio’s nose after he’s told a series of whoppers. Rather than being chisel-shaped like the woodpecker's, however, a hummingbird's bill is rapier-thin and sharp. Our Superhummer would be a Musketeer among birds. Mon dieu!
The total length of this adult male pileated woodpecker may be close to half a meter. Imagine a hummingbird with these proportions!
As the summer wanes, dogfights don’t cease among our remaining hummingbirds but a sudden decline in population density reduces the intensity of these interactions. Three days ago I noticed the absence of males in the yard. Male ruby-throated hummingbirds always leave in August, heading gradually toward the Gulf Coast. Females and juveniles remain somewhat longer, into October if conditions permit. During that time they may share the yard with dark-eyed juncos and pine siskins. These songbirds also travel south after nesting, but because they eat seed (among other reasons) their migration from Canada may end right here in central Minnesota.
I have often wondered whether the same birds somehow return year after year to our yard. Site fidelity is an aspect of migration that is of concern to biologists. But it can be difficult to prove. Banding studies shed some light on the question for ornithologists. Captured birds are fitted with tiny metal leg bands. Each band is stamped with a unique number, and may also carry a discrete color pattern. Bands allow individual birds to be identified upon sighting or recapture. At Hilton Pond Center in York, South Carolina, biologists banded 3,614 ruby-throated hummingbirds between 1984 and 2007. More than 430 of these birds came back to Hilton Pond the spring after banding. A couple returned several years in a row. Amazing information can be obtained from such simple techniques, but they require funding, staff, and infinite patience.
Audubon wasn’t terribly scientific when he described the ruby-throated hummingbird as a “glittering fragment of the rainbow”—but he was utterly accurate. I watch a little female perch atop our rain gauge between bouts of feeding and chasing. Her belly is rotund with nectar and she looks perfectly fit. This wee gem has a long journey ahead. I don’t know if she’ll make it back to this yard in the spring. But we’ll keep the nectar flowing, just in case.
I have often wondered whether the same birds somehow return year after year to our yard. Site fidelity is an aspect of migration that is of concern to biologists. But it can be difficult to prove. Banding studies shed some light on the question for ornithologists. Captured birds are fitted with tiny metal leg bands. Each band is stamped with a unique number, and may also carry a discrete color pattern. Bands allow individual birds to be identified upon sighting or recapture. At Hilton Pond Center in York, South Carolina, biologists banded 3,614 ruby-throated hummingbirds between 1984 and 2007. More than 430 of these birds came back to Hilton Pond the spring after banding. A couple returned several years in a row. Amazing information can be obtained from such simple techniques, but they require funding, staff, and infinite patience.
Audubon wasn’t terribly scientific when he described the ruby-throated hummingbird as a “glittering fragment of the rainbow”—but he was utterly accurate. I watch a little female perch atop our rain gauge between bouts of feeding and chasing. Her belly is rotund with nectar and she looks perfectly fit. This wee gem has a long journey ahead. I don’t know if she’ll make it back to this yard in the spring. But we’ll keep the nectar flowing, just in case.
Satiated after feeding, this hummingbird rests on a raingauge.
Follow the migration of hummingbirds and other species using maps posted by Journey North. These are updated daily based on data provided by citizens across the continent.
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