Dear Paul,
I bow to your superior knowledge and experience on this subject, but subjective colour perception can be problematic in the field. Certainly the nuances of various shades of orange (apricot ,orange, dull orange & ochre etc. ), the variability with lighting conditions and individual variation amongst individual birds can make subtleties of colour an unreliable field characteristic.
I'd value your opinion on several other aspects of these photos and their relative merits in the field.
The books I've looked have not been helpful on these matters (Thrushes-Clement and Hathway ,Advanced Bird ID Guide- Van Duivendijk and The Ripley Guide- Rasmussen and Anderton) , but perhaps I'm looking a the wrong texts and you might be in a better position to direct me to other books that might shed more light on the subject or share your personal experience on the questions relating to this 1st winter bird from Shek Kong.
Q1.Is the dark upper mandible helpful in the differentiation of Eye Browed from Brown headed in 1st winter plumage?
Q2.Is the scalloped undertail coverts helpful in the differentiation of Eye Browed from Brown headed in 1st winter plumage?
Q3.Can you sex the individual in Andy's images?
Q4.Duivendijk states that the 'pale underwing , underwing coverts are pale-brown-grey' are an important key feature of Eye browed Thrush.Would you agree that Brown breasted underwing coverts are
consistently darker?
Q5.I'm assuming that Black breasted (T. Dissimilis) and Izu Island Thrush (T. Celaenops) are pretty poorly described in 1st winter plumage ( and obviously might only occur with a wide stretch of the imagination), but do you know of any features which might help you exclude these species?
Many thanks your informed opinion.
With kind regards,
Eric
