Sunday Mirror (Northern Ireland)
African invader has us twitching
The sandy shoreline of Grafham Water is unlikely to inspire thoughts of the Sahara – even in searing temperatures under a blazing sun.
Yet for a few sweltering summer days earlier this month, the Cambridgeshire reservoir became the place to catch a glimpse of a bird straight from the coastal fringes of the planet’s biggest desert.
With its inky black eyes, legs the shade of polished jade and a golden bill, a cape gull straight out of Africa held court for a procession of thousands of twitchers from across Britain.
By rights, the sooty-backed seabird should have been languishing off the Atlantic coast of Morocco, but mysterious factors conspired to draw the bird to the edges of the Fens.
This was the first time a cape gull has been seen in Britain and writes the latest chapter of one of the most dynamic expansions of any bird in recent history.
To taxonomists, the cape gull is the African branch member of a super-species known as the kelp gull.
From the frigid wastes of Antarctica, along South America’s Pacific coastline as far north as Ecuador, across to
Australasia and then up the Atlantic shore of South Africa, kelp gulls flourish in a number of varieties.
Grafham’s individual was of the African subspecies vetula, a race that has spread from the Cape of Good Hope as far north as Europe in recent decades.
Hopes that this bird would wander to the UK have been strengthening of late after one was spotted at Paris Zoo, followed by others in Portugal.
Increased knowledge of bird identification – ably supported by the recent publication of the excellent Princeton University Press guide: Gulls of Europe, North Africa and the Middle East – is helping birdwatchers to be well prepared when confronted by vagrant species.
The book goes into great detail highlighting the key field pointers of an adult cape gull, with its black upper parts, heavy bill, dark eye and green legs, which contrast markedly with the pink legs of our native great black-backed gull.