Above three images, January 25th 2017

February 17th 2017

© A. R. Dean

The images above show a Yellow-legged Gull just into its 4th calendar year, which frequented Olton Mere, West Midlands, during January and February 2017. At rest, it looks very like an adult, including well-developed apical spots to outer primaries. However, there is a 'tell-tale' black mark in the centre of the tertials while the area of black near the gonys is evident (though even full adults can show a small black area towards bill tip - see this photo of a known 10cy individual). In flight, black streaks are evident on primary coverts and there is just a single mirror - on outermost primary.
As size and configuration (and favoured buoy for perching) were similar, it seems highly likely that the gull in the images above is the <same individual> - then in its 2W - which frequented the same site between November 2015 and March 2016 and again in July 2016, thus visiting now over a period of 16 months. This is another illustration of how individual YLGs become attached to a particular site.