Birdie Boy, Birdie Girl?

Heymatt:

How can you really tell that a bird is a male or a female?

-- Kay, the net

How can we really, really tell? Do I detect suspicion? Exasperation? Has someone been trying to trick you with this question? The first thing we did was send the research elves outside to flip some pigeons upside down and record what they find. That should keep them out of my hair long enough to come up with a real, real answer for you. I'm sure you won't be suspicious of me. Everybody knows that Amalgamated Alice L.L.C. offers the best information money can buy. Come to think of it, maybe that's why the Reader is free.

You might rightly be suspicious of any simple answer to this question. Don't know whether you're talking about hummingbirds or eagles, but a real answer depends on the species you're talking about. Some are easy. You can tell by plumage: the male is flashy, the female dull brown (ducks, common house sparrows and finches, blackbirds, peacocks). Or the male is flashier only during mating season (some herons and egrets). Or consider more obscure color variations (male yellow-breasted chats develop a black mouth lining at the beginning of the breeding season, which fades to match the female's mouth color by summer).

How about behaviors. Males of many species are much louder in breeding season (male mockingbirds sing at night, most male songbirds have a unique song in spring). If you spy two birds doing it, well, the female's on the bottom. One exception is swifts, which sometimes mate in midair. The ornithological version of the Mile High Club.

But say it's not mating season. And your parakeet just sits around doing nothing, saying nothing, and looking pretty much like all the other parakeets. How do you really, really tell if you've got a boy or a girl? Ahh, here come the elves -- very grubby -- definite resemblance to pooped-on statues. Maybe they can shed some light. According to the elf report, pigeons (and all other birds) only have one rear-end opening that serves multi-purposes. When birds do it, they match opening to opening. (Ornithologists call it the "cloacal kiss," but we can ignore that.) So it looks as if our final answer -- to be really sure -- you'll have to cut open the bird and poke around to locate testes or ovaries. The only weird exception is male ostriches and their cousins, some ducks, and a couple of other oddballs, which have rudimentary penises just inside their cloacal openings. A throwback to some distant reptilian ancestor, say the birdwatchers.

From the "Duh...Matthew, You Twit" Files

Hey, Matt: Actually, a better way to really, really know if a bird is male or female is by running a chromosome test. Birds have two sex chromosomes just like humans, except it turns out that while a male human has one X and one Y chromosome and a female human has two Xs, birds are the other way around. A male bird (cock) has two Z chromosomes ("homogametic"), while a female (hen) has one Z and one W chromosome ("heterogametic"). A veterinarian who handles birds can easily take a blood sample and have it analyzed. Much less invasive than checking the internal organs, although that works too. -- Susan Patch, P.B.

How could I miss that one? And avian forensics can help eliminate your parrot as a suspect in that big murder case, too. It'll be on CSI any week now.