some remarks to the 4cy type birds from previous posts (bumping it into a new post):
5028 and 5027 (same bird) apparently has only a p10 mirror, lacking a p9 mirror. its bill is fully alternate adult (no dark mark) - gonys spot looks red/red-orange and some
reddish hue seems to be present on upper mandible as well (not the first caspian with this trait but the first non-adult i saw).
5024 is how i'd expect a "typical" (if there is such) 4cy caspian should look, esp. shape and size of mirrors. ventral p10 tongue is about half the visible length of p10, this is about as far as in many adult michahellis but the rectangular 'cut' seems to be typical of caspian (while many caspians don't show such rectangular cut!)
5010, 5005 and 5004 has a shorter p10 tongue (less than half of visible p10)
5000, 5001 and 5002: now this one had me astonished most. either is it pretty retarded - with short p10 tongue, many dark underwing markings and a
full and broad tail band(!), plus there seems to be only a small p10 mirror, unfortunately not well visible, only in pic 5002. a similar pattern often is found in same aged michahellis (but p10 mirror usually differently shaped and ventral p10 tongue slightly shorter or absent) or - maybe in
eastern types of cachinnans??? such birds seem to occure in romania and central europe with a certain regularity, unfortunately we don't know their origin.
4995 and 4994 has a white shaft and pale 'borders' on both sides of it ( a feature i have not seen yet to this extent); p10 mirror is divided: rel long and without subterminal mark on outer web, smallish on inner web. p9 mirror small and round, restricted to outer web. pale iris.
- apropos pale iris - this caspian has been misidentified as argentatus recently, romanian black sea coast. it has a whitish-yellow iris:
http://www.birding.hu/img/39383-PEYHFS5 ... 4GQW34N0C3
