In the early 2000's (and recently as well), we have scored about 2900 adults on new, fully grown primaries and about 6800 adults on old retained primaries. Time to present some data. A first regression analysis for the whole year should be something like:
(for more info, see: http://gull-research.org/lbbgoct/05cyoct.htm at tables & graph - scroll down. For every month, it may be fun to extract data for that particular month together with this year plot.)
Two days ago, Scheveningen harbour. It appeared to be a very quite morning, the gulls simply did not respond to the 40 kg fish left-overs I had spread out. Two LBBG flew by, more interested in the bread than the fish; including this adult LBBG, showing slightly short inner primaries.