Views on likely hybrid
Posted: Sun Jan 15, 2017 1:08 pm
I volunteer with a UK gull-ringing group - despite birding for many years I have only in the past couple of years got interested in gulls, and volunteered with the group. Often we trap (cannon net) 'interesting' birds and I am always interested by the diversity of plumage and size even within a species - and also the discussion that ensues after the trapping.
One such case yesterday. See photos below. All agreed most likely a 1w/2cy hybrid Caspian x Herring - possibly a F2 or even F3. If the wing alone was found we felt sure it would be ID'd as Caspian, but the tail/rump and head streaking all point clearly to Herring. The bill is small and thin without much of a gonydeal angle. We did take metrics which I cannot recall, but it was at the smaller end of the range (female?).
Anyway I'd welcome any opinion and observations. As you can see it was colour-ringed (U5ZT) so hopefully it will be seen in future years and we can see what it grows up into!
Best regards
Mick
One such case yesterday. See photos below. All agreed most likely a 1w/2cy hybrid Caspian x Herring - possibly a F2 or even F3. If the wing alone was found we felt sure it would be ID'd as Caspian, but the tail/rump and head streaking all point clearly to Herring. The bill is small and thin without much of a gonydeal angle. We did take metrics which I cannot recall, but it was at the smaller end of the range (female?).
Anyway I'd welcome any opinion and observations. As you can see it was colour-ringed (U5ZT) so hopefully it will be seen in future years and we can see what it grows up into!
Best regards
Mick