Monday, March 14, 2011

Yellowhammer alternating song types

The course of an old railway line between Knockentiber and Springside in Ayrshire provides some good scrubby habitat for Yellowhammers (Emberiza citrinella). While surveying the territorial males there last May, I heard one bird that was singing two song types which were alternated almost one after the other. Most of the birds in this area sing about eight strophes (or deliveries) per minute and stick to one song type for quite long periods, though occasionally dropping the final ‘cheese’ phrase. Listen to this excerpt of a recording below of this bird and you’ll see what I mean. The first strophe I’ve termed the ‘Fast High’ song type/strophe and the second, the ‘Slow Low’ song type/strophe.

The ‘Fast High’ strophe is around 1.84 seconds with the first phrase comprised of a rattle of 10-11 syllables spanning 4.22-6.76 kHz and lasting 1.07 secs. The second phrase – just a single element, and the familiar ‘cheese’ of the popular British mnemonic for this species – is around 4.85 kHz and lasting 0.68 secs.

The ‘Slow Low’ strophe is longer at around 2.11 seconds with usually 12 lower-pitched rattles spanning 3.07-5.04 kHz and lasting 1.37 secs. The 'cheese' phrase is also lower pitched at 4.4 kHz, lasting 0.55 sec.

Another element in the song that is quite difficult to detect in the field with the human ear (and while listening to playback of recordings) is the very short (0.04 secs) and high pitched (up to 8 kHz) element that immediately proceeds the rattle. It is visible on the sonogram but see if you can pick it out in the recording.


Kah-Wai Lin said...

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Kah Wai

jas said...

this is amazing stuff, Fraser. Why do you think they sing these different songs? To attract mates? Or as territorial aggression against different males?

Fraser Simpson said...

Hi Jas, yes probably both, though some studies have shown that paired male Yellowhammers sing more during the female's most fertile period, as as a form of mate guarding. Females may also prefer males with a larger repertoire of song types... they may prefer yellower males too.

Fraser Simpson said...
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