why do mockingbirds have large repertoire?

I’ve been listening at the mockingbirds in my DC neighborhood. I counted what I thought were over a dozen song changes in rapid succession (at a certain point you lose track of what you’ve heard before, but I thought it was up to 18!).

My question: what’s the benefit of this? Are they accurately imitating other birds (i.e. other species find it “convincing”)? Is this a way of trying to dominate the airwaves to chase off birds that would compete for food? I can’t see how this helps with mating, unless they are poly-species sluts. :dubious:

Occasionally some closely related species may “adjust” their territorial calls when engaged in a conflict with each other, probably so the other individual will recognize the threat. But the mimicry of mockingbirds and other species is mainly directed at conspecifics, not individuals of other species.

There are several hypotheses regarding why males of some species have such extensive repertoires. One possibility is that singing variable songs is more likely to attract the attention of females, because they become habituated if the same song is repeated indefinitely. The easiest way to acquire new song types is to mimic other sounds in the environment. (And mimicry is not limited to other birds. Mimics have been known to imitate things like car alarms, cell phone rings, and chain saws.) It is also possible that having a large number of learned songs is an indicator of male quality. Since it takes time to acquire a large repertoire, this indicates that a male has survived for a long time and thus most likely is a superior competitor.

Thanks. Interesting. What about seasonal variation in song repertoires then?

Male mockingbirds are going to be singing mainly in the courtship season in the spring. Offhand, I would assume that the repertoire of each male will increase during the season as he hears and learns new songs, and that the repertoire of older males will be more extensive than younger ones. However, I have not tried to check to see if this has been confirmed through research.l

Want to see a real bird mimic check this out. Must be heard to be believed.

Maybe they are just bored with the same songs. A neighbor has multiple birds; one does both varities of home alarms, the back-up beeping of garbage trucks, and completely fools another neighbor lady with imitations of the woman’s baby crying. He (I guess) also does the local birds as well. Saturday morning you can’t shut him up as he goes through the whole repetoire.

Also, will someone please tell the one social-outcast birdhead in my neighbor’s backyard that, although the street lamps are indeed making it quite bright out, it is not in fact dawn at 3AM and he should save his dazzling vocal improvisation for the when the sun begins to rise, like all his friends do?
stupid dyschronic bird