VAGRANT SPECIES DIARY
Kelp gull, Cambridgeshire
GULLS ARE A POLARISING FORCE IN THE field of birding. For some observers the identification and taxonomic challenges posed are irresistible, leading to long hours spent down the local refuse tip or gull roost; to others the complexities of ageing and moult, whilst studying the gonydeal angle (the point where the bill turns upwards near the tip) and the numbers of mirrors and tongues on the diagnostic wingtip patterns are, well… you’re probably starting to see the problem already.
But recently many birders took a sudden interest in gulls because a rather special one had appeared at Grafham Water in Cambridgeshire. On 7 August 2022, a keen local birder recognised an odd ‘black-back’ with noticeably long pale blue-grey legs and a jet-black eye, the key features of the Cape gull. It’s an African subspecies of kelp gull, which is a mainly southern hemisphere species that has never occurred in the UK.
With a smattering of Western European records mostly from Iberia but with two also from Paris, it has long been predicted to make it here, though how many may have been overlooked remains anyone’s guess.
With more photos coming to light online, the bird’s key size and structural differences were confirmed when compared to the rather similar native lesser and greater blackbacked gulls. Large gulls like these take four years to reach sexual maturity and the tatty dark brown rather than black wings betrayed this kelp gull as a two-year-old youngster.
The gull tolerated the crowds at Grafham for a few days, whilst loafing with other gulls and sometimes allowing close range scrutiny as it feasted on dead fish along the dam.