On the wild side—July, 2011
by Tina Mitchell
When I start to write one of these species accounts, I think “What is interesting about this species?” With hummingbirds, though, what isn’t interesting about them? The smallest of all birds, hummingbirds weigh between 0.1 and 0.3 ounces (2.5 – 8 grams)—or about the same as 5-15 M&Ms for most of the hummingbirds we see in Colorado. Probably the most striking aspect of hummingbirds is their unique and extraordinary ability to hover indefinitely in the air, as well as fly forward, backward, side to side, and even upside down for short distances. Their wings beat faster than the eye can discern—for the species found in Colorado, that’s around 50 beats per second. Their very long tongues can extend far beyond the tips of their bills, unlike most other birds. Their bills allow them to extract nectar from deep within tube-shaped flowers. They don’t suck up the nectar, though. Instead, they actually lick it. Capillary action then moves the liquid up 2 partial tubes on the sides of their tongues and into their throats. (Small insects such as gnats and aphids also make up an important part of their diet, providing protein to supplement the sucrose of nectar.) Their hearts beat at 1,250 beats per minute when they are flying; even at rest, they still clock 250 beats per minute. Yet when temperatures fall, they can dramatically slow their body functioning through torpor, where their heart rates can drop to 50 beats per minute and their body temperatures fall from ~110o F to 55o F. As long as they have sufficient energy stores, they can emerge from torpor unscathed when the mercury rises.
The 17 species that breed in the U.S. and Canada represent only about 5% of the more than 320 hummingbird species in the western hemisphere. In Colorado, we have 2 breeding species. By far the most common and widespread is the Broad-tailed Hummingbird (left); Black-chinned Hummingbirds (right) breed in some parts of our area as well. If you see the males of either species in a perfect light, you’ll see a flash of diagnostic color from the gorget (the feathers at the throat)—a brilliant rose-red for Broad-tails and a deep purple for Black-chins. In a less-than-perfect light, the throats just look dark. (Females of these species can be very difficult to tell apart—I won’t even get started here.) Thanks to Wikimedia Commons for the free-use photos; photographers Factumquintus (left) and Mdf (right).
These fascinating creatures have spawned a number of “wives tales,” ranging from the harmless (e.g., hummingbirds will starve if I don’t keep my feeders full) to the truly bizarre (e.g., hummingbirds migrate on the backs of Canada Geese). Neither is true. Another “myth” arises around feeding them. Some people put out hummingbird feeders filled with sugar water to which red coloring has been added. (Many store-bought mixes do this.) True, hummers are attracted to the color red. But the artificial coloring is totally unnecessary. All you really need is a sugar water solution (1 part sugar to 4 parts water is commonly used) and a bit of red on the feeder itself—even just a red ribbon will do. A large part of hummers’ lives involves checking out red things. They’ll find it! Also, some folks worry about leaving feeders out in the fall, for fear that their presence will keep the hummers from migrating. Have no fear—hummers will head south when they need to. I generally leave our feeders out for 2 weeks past the last time I see or hear one in the area. Rather than harming them, you could actually offer a big help to a late-migrating (often first-year) hummer during a time that flowers and insects are becoming scarce.
The Broad-tail’s scientific name—genus and species—is Selasphorus platycercus. The genus name comes for the Greek for “flame bearer”—a reference to its iridescent gorget. The species name derives from the Greek for “broad tail” (platus = broad; kerkos = tail). The Black-chin’s is a bit odder: Archilocus alexandri. The genus honors the Greek poet, Archilocus. (The fellow who was naming some hummingbirds in the early 18th century named several genuses after classical artists. Go figure…) The species name honors M.M. Alexandre, a French medical doctor who collected Mexican birds in the mid-1800s. Their common name arises from the hum of their beating wings. A Broad-tail sounds like a cricket chirping as it flies by; a Black-chin produces a lower hum—more like a June bug (if you know that beetle). The Broad-tail also actually has a broader tail than many other species of hummingbird (although it’s very hard to see that unless you have the bird in your hand). And the Black-chin has a band of black feathers immediately under its chin. (Yes, birds have chins—directly below where the beak meets the head.) But this can be very difficult to see without perfect light.
In July in Colorado, the Broad-tails and Black-chins are often joined by 2 other species passing through—the very aggressive, gorgeous orange-red Rufous Hummingbird and the teeny, tiny Calliope Hummingbird (3” long!). Let’s save interesting information about those 2 species for another write-up. But add these 2 species to the mix of local breeding adults with their newly fledged kids and crazed zipping and zooming can erupt near any food source. Stand back and let the “hummingbird wars” of July begin!
You can find many more interesting tidbits about these amazing little jewels here.