Good Natured: The Trees Are Alive with Sharp-Dressed Men
I believe it was that little ol' band from Texas, ZZ Top, that noted, “Every girl crazy 'bout a sharp-dressed man."
As I recall, the 1980-something song explains how things like a clean shirt and new shoes, a silk suit and other accoutrements practically guarantee success with the ladies. But even though the song was written by, and for, Homo sapiens, it would appear many avian species have taken heed too. Want proof? Just head outside, and look up.
Right now the trees are alive with sharp-dressed men. Aptly named yellow warblers, their breasts streaked with reddish brown, are flitting about the newly leafed branches, feasting on insects while sporting their festive breeding plumage. Male scarlet tanagers are doing the same, decked out in brilliant, knock-your-socks off red set off by deep black wings and tail feathers.
Male Baltimore orioles, in orange and black, are also in the treetops but can be lured down to eye level with treats like grape jelly (please none with high-fructose corn syrup) and oranges sliced in half. And at the feeders, male rose-breasted grosbeaks and indigo buntings are gobbling seeds without fear of messing up their Sunday, er, breeding season best.
Without a doubt, the woods are alive with color right now. But what of those girl birds? Are they really going crazy?
Hmm, well, crazy might be a bit of an overstatement. But they certainly are paying attention.
In species that display sexual dichromatism--that is, males and females that are different colors--the bolder and brighter, the better, because those beautiful hues are more than just pretty. They also can indicate that a bird has consumed a diverse and nutrient-dense diet. And a male who is capable of finding food and keeping himself well nourished is likely to do the same for his mate and offspring. (My friends who are marriage counselors may disagree, but remember, we're talking birds here.)
That fitness extends to other aspects of reproduction as well. A fit male will be able to more effectively defend his territory against all sorts of trouble. His bright colors show others of his species that the space is already occupied and his general hardiness gives him the stamina he needs to shoo away other potential threats.
If you've ever encountered a male red-winged blackbird in defensive mode, you know what I mean. He'll flare those bright red patches as a means of warning trespassers, and follow it up with a dive and even a bump if the interloper doesn't take the hint.
His females (yes, he's working to defend more than one nest at a time, which certainly helps explain his diligence) benefit from those efforts by living in a territory that's well supplied with resources and also relatively safe from harm.
(I know what you're thinking. Male redwings don't just defend, they attack. But you know what? They will not fly toward eyes. As you're out and about and hear their familiar “conk-a-reee" song, try and spot the individual doing the singing. Then stare him down. I guarantee he will not bop you on the head.)
In some bird species, the brightly colored male will even pitch in and help build the nest. Take the male northern cardinal, for example. He might not do any actual construction, but he's more than willing to help with the heavy lifting, readily bringing his mate nesting material like twigs, bark, grass and moss so that she can make a custom-fitted abode for the offspring to come.
He jumps back into action once the eggs hatch. Whether they're his own offspring or those of a local brown-headed cowbird, Papa Cardinal delivers all manner of insects, spiders and other arthropods, stuffing juicy morsels into hungry maws from sunup to sundown.
(Papa Cowbird, all shiny and black with a brown head, is sharp looking in an understated way. He spends the spring and summer months mating with various female cowbirds, which then deposit their eggs in other birds' nests in a practice known as brood parasitism. Freed from the burdens of offspring-rearing, a single female cowbird can produce as many as 40 eggs over a breeding season.)
Let's see, where were we? Oh yes, those sharp-dressed men.
It's true, many bird species show us that clothes—I mean feathers—really do make the man. However not every species takes the sharp-dressed route.
Like the boys in ZZ Top, some male birds are decidedly more low-key in their approach to appearance. But, also like the Houston-based band, they can sing. Next week, we'll take a look at the role of song in avian courtship and breeding success.
Pam Otto is the outreach ambassador for the St. Charles Park District. She can be reached at 630-639-7960 or firstname.lastname@example.org.