Well, that was a disappointing turnout given the apparent 'interest' in crossbills and the amount of crossbill sonagrams that are being posted on blogs etc. I don't think there is going to be a rush of contributions so well done to Dougie Preston and Stephen Menzie for being bold enough to have a go, and not a bad go at that, getting the species correct.
I guess people just don't want to appear "wrong" in public and perhaps this goes to demonstrate that identifying crossbills from sonagrams is just as difficult, possibly more so, than identifying them through a scope or images ? Or maybe my example was too difficult ? Well hey, it is a 'real life' snapshot of crossbill behaviour afterall !
Okay, there were two species, Common and Parrot Crossbill and of which there were 4 Common Crossbill individuals of the same 'type' (1A) and only one Parrot specimen. So a total of 5 Crossbills. Only the Parrot gave both a Fc and an Ec. Admittedly the actual numbers of birds was easier to ascertain from the recording which neither Stephen or Dougie had, though it can be seen on the sonagram.
So, here is my analysis ( all timings given are approx.):
1.0 secs = 2x Fc1 types. I call these "parroty" Fc1's as they are easily confused with Fc2. However, they much higher pitched than Fc2 Parrot and the descending element is much weaker ( thinner on the sonagram). Notice one individual is slightly lower pitched than the other, but still higher than Parrot.
1.3 secs = Bird "two" of Fc1. Continues through sonogram faintly.
1.4 secs = EcA Variant, bird "three". Fundamental has an initial down turn or upturned 'horn' appearance. The harmonics are slightly different from typical EcA.
1.6 secs = Bird "one" of Fc1.
1.9 secs = EcA variant, bird "four".
2.0 secs = Fc1, bird "one".
2.2 secs = EcA bird "four".
2.6 secs = EcA bird "four".
2.8 secs = EcA bird "three".
3.3 secs = EcD Parrot Crossbill. There is no coinciding Fc here ( sorry Dougie) it is a feature of the excitement call structure (though may be related to a fc?). Notice how the Parrot EcD is lower piched and of a considerably shorter duration than the Common Crossbill EcA ( which they can be confused with aurally).
3.8 secs = EcA bird "three" and "four" together.
3.95 secs = Fc2 Parrot Crossbill - same individual as 3.3 secs. Compare with Fc's at start of sonagram, notice the Parrot calls are lower in frequency ( I call it pitch cos I hear it) and are a much stronger in amplitude. This gives a "choop" rather than "cheep".
4.1 secs = EcA bird "three".
4.2 secs = Fc2 Parrot ( same bird as 3.95 secs).
The appearance of a seemingly extra component on the Parrot Fc's at 3.95 and 4.2 secs can be misleading and may in the past have led to examples of this call being classified as Fc3 Scottish ( all will become clearer soon !). It is a harmonic of the main trace in my opinion. Only large billed birds I have handled have given this call on release.
So well done lads, other than the Scotbill reference, you got the right answer ( though the working out may not agree with my own analysis).
Just shows what information you can get from a sonagram. And there are people that say Crossbill calls are baloney ! Their loss.......