We rely on colour ring resightings such as this to help us understand juvenile survival. Adult survival is relatively straight forward for us to calculate as the colour ringed birds return to Skokholm each year for the breeding season (over 90% of adults survived between the 2015 and 2016 breeding seasons). Perhaps the youngsters will also breed there one day (allowing us to improve our survival estimates) but many may select other colonies. So please keep the sightings coming in. If anyone fancies a really productive bit of birding, then track down your local Great Black-backs and check them for rings (even a count of birds which definitely didn't have rings would be interesting in a Pembrokeshire context).
W:099 at approximately 16 months old. If you get to see what the gulls are feeding on then this would be great to know too. (c) Pamela Marshall