How come parrots, etc., talk but chickens don’t?

SDStaff Colibri replies:

Chickens are perfectly capable of speaking, Damien, they just have stage fright. They don’t talk because they’re chicken.

Heh. Sorry, I just couldn’t help myself.

Moving right along. In most birds, calls and songs are innate — that is, there is no learning involved. A young bird raised in isolation will produce its species’ characteristic vocalizations without ever having heard them before. The ability to learn vocalizations, and therefore to imitate them, is limited to three groups of birds: the songbirds (or passerines), which make up about half of all birds; the parrots; and, rather surprisingly, the hummingbirds. Among the passerines there are mimics in many groups, such as the starlings (including the mynas), mimic-thrushes (including the well-known mockingbird), true thrushes, and lyrebirds.

Why exactly birds mimic sounds has long been a puzzle. Among parrots and perhaps other social species, mimicry of the call of the mate or of other members of the flock may help identify the members of the group and thus foster pair or group cohesion. When your pet parrot exclaims “Pretty bird!”, it’s probably because it views you as its mate, or at least another member of the flock.

But many birds mimic the calls of other species, and have been known to imitate such things as telephones, alarms, and chainsaws. Why? The best guess is that imitation is the easiest way to increase the repertoire of calls a given individual can make. And what’s so good about having a big repertoire? There are several possible benefits: (1) A big repertoire can indicate to a female that a male has been around awhile and thus is a good survivor, with enough experience to be a suitable mate. (2) The response of a female or rival to a particular song is likely to decline after long repetition. Constantly changing songs may help to maintain interest in the listener. In fact, it is often species that sing continuously for long periods like the mockingbird that have the largest repertoires. (3) Changing songs could interfere with a rival’s — or perhaps a predator’s — ability to track the singer’s wherabouts.

Given the fact that parrots and passerines have vocal learning and can be taught to talk, one wonders at what the capabilities of hummingbirds, which also have vocal learning, might be. Always at the forefront of ornithological research, I’ve decided my next project will be to teach a ruby-throat to say, “Hey, pal! How about re-filling this feeder pronto!” in a thick Brooklyn accent.

SDStaff Colibri, Straight Dope Science Advisory Board

Send questions to Cecil via cecil@straightdope.com.

STAFF REPORTS ARE WRITTEN BY THE STRAIGHT DOPE SCIENCE ADVISORY BOARD, CECIL’S ONLINE AUXILIARY. THOUGH THE SDSAB DOES ITS BEST, THESE COLUMNS ARE EDITED BY ED ZOTTI, NOT CECIL, SO ACCURACYWISE YOU’D BETTER KEEP YOUR FINGERS CROSSED.