Saturday, 26 March 2011

Toop, Toop, Choop, Choop !

No, I haven't lost my mind, but rather a short discussion of phonetic crossbill calls ! I get many references in emails describing crossbill calls in the field using phonetic descriptions. Most existing phonetic descriptions in the crossbill literature, other than those by Magnus and Sound Approach, are errant or misleading in my opinion, particularly for Loxia scotica. They also may not reflect the 'current' evidence either. Actual audio recordings are preferable, however the following may offer some clues in separating Parrot Crossbill from Scottish Crossbill in the field.

Parrot Crossbill

Flight Calls are a distinct "Choop" or "Chup", emphasis on the "oo" or "u". These can also sound 'flutey' (a term often wrongly used to describe Scottish flight calls) due to a pronounced harmonic that is often present ( and which can make them appear on sonagrams like published Scottish flight calls). Birds may also give a more subdued "tip, tip, tip" call when in 'cryptic' flight (similar to those given by Bullfinch). They sometimes give these on release after being captured and ringed. These can appear as single descending streaks on sonagrams.

Excitement calls are a lower pitched (than flight calls) 'cluck' reminscent of a Blackbird alarm call, or more closely a Jackdaw (and between the two in 'pitch' and timbre). Aurally, Parrot excitement calls sound very similar to Common Crossbill EcA ( or "British" ala Sound Approach) and it takes much experience to separate them by ear in the field. In such cases a look at the bill should help diagnosis, but not always it would appear !

Scottish Crossbill

Recent evidence that I have collected and matched with biometrics shows intermediate billed (Scottish) give a 'di-syllabic' flight call sounding as a "t-reep" or sometimes a 'lispy' "th-reep". This is much higher pitched than Parrot flight call and in fact can not be confused aurally with ANY commonly occuring Loxia in the UK ! NB. THESE CALLS ARE DIFFERENT FROM THOSE THAT HAVE BEEN PUBLISHED !

Scottish excitement calls are much more 'hollow' than Parrot Crossbill, and sound like a "tonk, tonk" or "tunk, tunk" - I think it sounds more stacatto (abbreviated) than Parrot and timbrally similar to wooden claves or woodblocks being struck (for any would be percussionists out there !). In the field it is VERY similar in tonal and timbral quality to Common Crossbill EcE or "glip" excitement call, especially if the harmonics are less pronounced ( which makes the call look very similar on a sonagram too !). This is a RARE call, by far my rarest recorded Crossbill Excitement call, suggesting this call, like the flight call, may be in a state of flux - time will tell.

One word of caution. Often people describe large-billed crossbills giving very 'deep calls'. In cases like this, assuming they are correct, they are describing Parrot Crossbills as both Scottish flight and excitement call are higher pitched than Parrot, and typically much more like those for Common Crossbill. It is worth reiterating that 90% of photos I am sent or see on the web of presumed 'Scottish Crossbills' are in fact actually Parrot Crossbills (in my experience) ! My advice: leave the camera at home, buy a mic and recorder, think about the above, and learn about the vocal dialects of the crossbills in your area.

3 comments:

Matt said...

I’ve continued to collect new recordings of Newfoundland Type 8, and they too appear to have changed their call. All the other Types here in the States however, appear to be quite stable (known recordings go back to late 1950′s). Perhaps each Type across the pond has a fair amount of variation and therefore perhaps some of the Types across the pond have been split too far. Lindsay any thought as to why the Scottish has changed it’s call? You have a new email?

cheers,
Matt Young

Matt said...

I agree, it's speculative for Groth to describe a Type 8 based on the two 4-second Pitocchelli recordings from Cape Bonavista. I just received another new batch of Newfoundland recordings.

Thanks for the comments Lindsay.

Matt

Loxia Fan said...

Hi Matt,

Good to hear from you ! Yes, email changed a while back - I can be contacted in my Profile on the right hand column via the Yahoo email address.

Regarding the splitting of calls I mentioned to you last year that Fc1 seems to have many variants and that in reality (practicality !)there appear to be predominantly "Fc1" and "Fc4" Common types in the UK - this was following discussions I had with Ron Summers last year when we were ringing crossbills, and we both seemed to agree on this. Here in NE Scotland we currently have a 'strain' of Crossbills that irrupted here last Summer that sound like Fc4 ("glips") but in actual fact are variants of "parakeet" 2B types eg. they are giving a Fc1. I caught a male in Jan who gave one type of this call on release, then was joined by his female and then sychronised his call to his mate, who gave the variant call.

Regarding Scottish changing its call I can only comment on the evidence that I have collected and can't account for the data of other researchers, though the calls I have been recording are different from the published ones. This includes the excitement call NOT just the flight calls ! I hope to combine my data set with that of Ron Summers and with Alan Knox and we will see what it all says - perhaps definition of "Scottish Crossbill" when relating bios to calls will be reviewed. Alan's stuff will give a historical perspective for the same study areas that I currently work, and these go back to the 70's.

The problem you have in claiming that percna (NF Crossbill for other readers)has also changed its call is that there is only one recording from Bonavista, by Groth in the 1980's ! IMO that would not be enough to claim the call for percna has 'shifted' eg. shifted from what: one bird ? !

I think we can only describe what we have currently and hypothesize from there. It would seem that Eurobills also have much variation, possibly shifts, in calls. Whether these are caused by hybridisation or sympatric 'pressures' we will have to see.