Scoring Scopoli's - A useful ID pointer and assessment of Irish birds to date
A recent thread on birdforum got me thinking about Scopoli's Shearwater again. The original poster provided two images for ID, with one suspected of being a Scopoli's (top here) and obviously so, and the other a Cory's in similar conditions. After years of watching both Scopoli's and Cory's in seawatching conditions (rather than from pelagics) I was of the opinion that Scopoli's often has an appearance of having a narrower, paler more broken leading edge to the hand between the carpal joint and the base of P10. So I decided to run an image survey of both Scopoli's and Cory's to try and assess this. (Fair use applies to all images used here). Scopoli's examples Cory's examples Quantification of these things can be difficult, but I attempted to apply a scoring system, between 0 and 3 to the primary lesser and median coverts, and the marginal coverts in terms of "thickness" (i.e how far dark feathering extended towards the median of great...