Last night, I was walking with a friend, and I pointed out a Catbird that was mimicking a Blue Jay’s call. He was very surprised because he thought that the only bird that mimics other calls was the mockingbird.
Probably the world’s best bird call mimic is Australia’s Lyrebird. There is this fabulous video of one mimicking construction noises at the Adelaide zoo, which I think you would enjoy (hey, it’s Friday, treat yourself!).
He is literally superb! According to Wikipedia: “The lyrebird’s syrinx is the most complexly-muscled of the Passerines (songbirds), giving the lyrebird extraordinary ability, unmatched in vocal repertoire and mimicry.”
Attenborough also plays with these birds, showing how they can mimic tourist camera snaps: http://www.youtube.com/watch?v=VjE0Kdfos4Y
(No offense to my beloved Attenborough, but I actually think the first video is more impressive.)
Closer to home, the most familiar and adept bird call mimic is the Northern Mockingbird. In a study by Derrickson (1987), he found that a single male mockingbird can have over 400 unique songs in its repertoire!
But there are several other North American (and Australian) species that mimic. For example, other members of the mockingbird’s family (Mimidae) also incorporate snippets of other bird song into theirs: the grey catbird (here is a video), the sage thrasher, and the brown thrasher. Here’s a page that compares the three: http://www.math.sunysb.edu/~tony/birds/mimics.html
Blue Jays sometimes mimic hawk calls (like this enthusiastic guy).
And if you really start digging, you find that starlings, buntings, shrikes, tits, thrushes, larks, ravens, bowerbirds… *pant*pant* http://publishing.bl.uk/cd/bird-mimicry. In fact, according to a review by Hindmarsh (1986), 20% of Passerine birds mimic occasionally, and 5% are considered habitual mimics.
Perhaps this shouldn’t be so surprising, given that birds learn their songs by mimicking adults. But why do some birds mimic other birds (and non-avian sounds)? There must be some disadvantage in that it makes species specific recognition for mating purposes more difficult.
There is substantial evidence that habitual mimics don’t mimic to deceive (Hindmarsh 1986). It may, however, allow for the identification of individuals (i.e. every male has a unique repertoire) or it may allow for higher fitness of males with a larger memory (i.e. the capacity to remember and repeat more songs), which may in turn be related to other measures of fitness.
Or, as Hindmarsh suggests, it’s possible that Passerine song has no functional significance…but that’s not a very interesting hypothesis, is it?