Tuesday, April 17, 2012

Bird Song


I generally appreciate birdsong as I walk around campus. However, I always find myself grumpily thinking about strangling a bird and eating it for dinner when they wake me up too early in the morning. But regardless of my annoyance, I usually walk around Houston fairly amused by the chattering that goes above my head in the form of song. But to my human ears, it all sounds like chirp chirp chirp, if you know what I mean.

So it was to my great surprise when I found out that birdsong has actually changed depending on the environment. In fact, the sheer difference between the city and a forest leads birds to have a change in bird song, and consequently in signaling. This divergence was noted in an article that compared the songs of great tits within the city and the forest where it found that songs changed both in duration and also in frequencies. [1]. The great tits in noisy locations (city) sing at a higher minimum frequency, most likely to be heard over the ever-present lower frequency white noise of the city. Furthermore, these birds in the areas with greater sound pollution had a restricted range in their repertoire of songs and

This study implies that an environment changed by humans can potentially alter the communication of a wild bird like the great tits. This amount of change in the communicative aspect for wild birds domesticated within a city can affect breeding opportunities and change a species' drastically. So while my own ears might be hearing chirp chirp chirp, the population of birds in a city might actually slowly be changing their own birdsong to something a little less diverse than expected in the wild, which might even alter mating behaviors in the future.

[1] Slabbekoorn, H. & Peet, M. (2003). Birds Sing at a Higher Pitch in Urban Noise. Nature. 424, pg 267.

I am a Great Tit!
from http://robandmazza.blogspot.com/2011/05/chick-  factor.html

1 comment:

  1. Could, then, urbanization lead to speciation? If bird song is changing that much, and mating is affected, the populations might be technically isolated, right?

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