Gull ID, putative Bonaparte's? - Italy, 2018/02/08
yesterday 8th February 2018 i saw a strange gull over the rubbish dump in Gorla Maggiore, Varese, Italy.
It was circling along with tens Black-headed gulls, CG and YLG. The difference of the underwing pattern was immediately visible, giving an overall pale appearence of the underparts of this bird.
When i decided to took some pics, the group of the gulls glided further, so i tried to make some "group photo", hoping that it was in them. Fortunately i got it.
It hadn't the typical pattern of the BHG with an evident black area of the inner primaries, but this area appeared white/greyish. You can compare different pattern from the photos below, where BG(?) and BHG are in the same light condition and in the same position. (Clarification: the dark underwings and underparts are affected by shades in all gulls in the photo). I immediately thought about a BONAPARTE'S GULL.
About size, i was too concentrated about the underwing pattern, so i didin't focus a lot this kind of difference. It seemed to be not so different from BHG, maybe a little bit smaller, but few cms, so i'm not completely sure. Anyway, we know there's sometimes few difference between a small BHG and a normal-size BG (you can find lot of images on the web).
Finally, the bird appeared as a 2cy, with dark tail band and some signs of immaturity on the upperparts.
Sorry for the poor pics, but the all white sky and distance were not the best for good photos.
I hope to know American birder's opinion.
Thanks in advance
P.s. In the photos the translations are: ('Comuni/Comune'-> Black-Headed Gulls, 'Gavina'->Common Gull, 'Bonaparte'->Bonaparte's Gull).
Last edited by Grus91 : Friday 9th February 2018 at 10:13.