Thursday, 26 June 2008

My Heid is Splitting !

More Gollocks on Bird Forum HERE ( see in particular post #62). Now, it is not that I have a major problem with classifying Loxia scotica as a race of crossbill rather than a species. Rather, the problem is a race of what exactly - Common or Parrot, something which the poster just so happens to conveniently omit ! ? One, would assume the former but how do we know ? The fact that genetically all three are, to all intents and purposes, 'the same' offers no clues either. So, in sharing the same ancestry, which Common, Parrot and even our old friend Scottish clearly must do, when does a clinal form stop being merely a race and become a species in it's own right ? Yep, it's that old problem: it is our definition and understanding of what constitutes a 'species' that is problematic rather than the organisms themselves that just do 'what they do'. I do not profess to understand the mechanics of speciation - I have Ian Newton's fantastic book on Biogeographic Speciation but must confess I only read the Crossbill bits ( and, true to form, looked at the pictures).

There are now hints and murmurs as to splitting Winter Wrens so hopefully the troglodytes of Fair Isle and St. Kilda will deflect from the Crossbills. Who knows, maybe the bird guides from Heatherlea will run trips to these places to show clients 'species' that they themselves do not believe really are species ala what they apparently do with Scottish Crossbill - that is if they (the wrens) haven't all moved to the Lodgepole Pine plantations of Sutherland or hybridised with Hebridean Dunnocks by then (only regular reader to my rants will get this one) ! Maybe they can "work with the scientists on technology" to enable 'retrospective' identification of the vocalisations of the wrens (little hint: it exists already in the form of a microphone, recorder and a copy of Raven Lite-duh).

2 comments:

Alastair said...

Lindsay,
Please would you email me at birdsvc62@gmail.com I've got some crossbill pix I'd like your opinion on if you've got a moment. There's a link on my blog at http://whitbybirding.blogspot.com/
you might like to comment on what I've posted also?

Thanks

Alastair Forsyth

Loxia Fan said...

Had a quick lookie. Bird in photo no.1 is a curvirostra - 2cy. Bird in photo 2, male, is possibly the same as the one in photo 3 ? The juv in photo no.2 is a curvirostra.

Regarding the big-billed male I have seen curvirostra with really big mandibles several times. In photo no.3 the culmen for me is way to shallow for Parrot which is generally much steeper or downcurved - a feature of pine adapted crossbills ( some say 'pine selected', for me the terms are synonomous !). Also in photo No.3 the bird's bill is open and there may be a drop of water on the lower mandible exaggerating the gonys. Most likey an abberant big-billed curvirostra.

Hope this helps !

Lindsay