The Porlock Iberian Chiffchaff found by Andy Pym. There has been some initial concern that this bird at times has been singing like Chiffchaff. The notes below are what I've gleaned from the last couple of days. I don't pretend to have vast experience with this species so any comments either agreeing or disagreeing will be welcomed.
Firstly it looks good for one: It looks like it's got long pointed wings. The underparts are white with a wash of yellow on the throat and vent (some photos show this better than others). The supercilium has a yellow tinge in front the eye, it has a very pale bill base and no eye ring.
The sonogram of the calls look absolutely superb. They are absolutely spot on perfect for Iberian Chiffchaff starting at about 5kHz with a downward inflection. To be honest, you could almost stop here as this call is so text book perfect.
Iberian Chiffchaff is known to have two types of song, so don't be alarmed, as I and others have been, that it occasionally sounds like a Chiffchaff. This is supposedly called its conflict song because it is used during antagonistic interactions with other males. As there's a pair of Chiffchaffs nesting right next to this bird, it's hardly surprising that it's doing this. The Iberian Chiffchaff has been regularly flying down to the nest of the Chiffchaffs but it usually leaves quickly and closely followed by a Chiffchaff! Note that at all times the Chiffchaff sounding song is in short bursts unlike a collybita that can go on singing for ages. The sonograms of this song show that the frequency range is between 3-6.5 kHz, never reaching 7 or 8 kHz that collybita does.
The most distinctive song is the advertising song. This bird usually sings in two parts, rather than the classic three part song. This is supposedly normal, though I would prefer it if it did some upward inflecting 'wheeps' in the middle. Again, the frequency range is always 3-6.7 kHz and the spacing between notes is very short during the final 'rattle'.
Update: I've had another look through all my recordings, and have found the last recording and sonogram. Whilst this is not as good quality as the other recordings, it does clearly show the upward 'wheet' middle part of the classic three part Iberian Chiffchaff song. This is shown in the sonogram (labelled Part 2), and is audible on the recording. This is supposedly never shown by collybita, so as far as I'm concerned this nails it.
2 June 2012
After a failed attempt last year, I finally had a day out on Skomer. My camera nearly overheated! It's difficult to quite take it all in, but a brilliant day. The images look far, far better at a bigger size but for now this is all you get! Puffins, Guillemot and Razorbill. Technically, and boringly, photos on Skomer are a great challenge. Most of the birds are black and white for a start, which makes correct exposure difficult - getting blacks and whites right on the same image is fun. Also the birds are too close, something I'm not really used to - I'm much more at home with a gert big lens.