Sunday, April 18, 2010

Robin poetry

I want to know what the birds are saying!

Robins make up their songs in a series of verses. most of the time i hear them sing about 4 to 6 phrases or tweets per verse. Robins usually know about a dozen or two different kinds of tweets. Often at the end of each verse they will sing a very high pitched 'hissely'. When analyzed with a computer, we find that robins sing about 50 different kinds of hisselys. Odd. I don't remember how they learn their tweets, either from each other or they make them up as they mature. Either way, each robin knows a distinct set of tweets.

What are they saying? How carefully are they composing? According to studies reported by Donald Kroodsma, in his book "the singing life of birds" many birds definitely are composing as they go. Either learning from each other, reacting to each other... The brown thrasher has been recorded to know about a 1000 different tweets, which it sings in very quick succession, improvising many on the spot. A Charlie Parker of birds.

http://www.thesinginglifeofbirds.com/

here's a Robin reciting poetry at Riverside Park in NYC.

video

The first step in decoding what this robin is saying is to count the number of tweets in each verse:

riverside robin sings
5
6
7
7
6
6
6
6
6

then you chart out his song:

5 _ _ _ _ _
6 _ _ _ _ _ _
7 _ _ _ _ _ _ _
7 _ _ _ _ _ _ _
6 _ _ _ _ _ _
6 _ _ _ _ _ _
6 _ _ _ _ _ _
6 _ _ _ _ _ _
6 _ _ _ _ _ _

then you start listening for tweets you recognize and fill them into the spaces. eventually you transcribe his song. Here is my transcription:

riverside robin:
\ \ ~ ~ '
\ \ ~ ~ w V (end of verse)

\ \ ~ ~ ~ w
\ ~ ~ ~ w V (end of verse

^ v ^ v _ .
^ v ^ w ~ w

^ v ^ v ^ v
^ v ^ v ^ v
^ v ^ v ^ .

Now of course this is as a human hears it. I hear a set poem. I don't know how robins hear it. I would like some day to record lots of robins and hear if they often make structures like this.

I suppose the test is to make up our own robin poems and see how other robins respond to them. Ongoing research!