MORE than 1,200 avid birdwatchers, some from as far afield as France and Lithuania, descended on Rainham Marshes last week – to catch sight of just one bird.

It may not look much but spotters were all in a flap over this adult male slaty-backed gull – a first-time visitor to the UK.

The wayward wanderer set up nest at the wildlife site and nearby Rainham landfill – a long way from its native Russian Far East and Japan.

It was first seen by ornithologist and managing editor of Birdwatch magazine, Dominic Mitchell, last Thursday (January 13).

Further sightings followed on Friday, and as word spread hundreds of fans turned up on Saturday from across the country and the continent.

They formed one of the biggest groups of ‘twitchers’ in the UK in recent years

The gull a huge 27-inches long, normally migrates along the Pacific coast in the winter months.

The gull’s first appearance in the UK is believed to be related to the increasing navigability of the North West Passage linked to the melting of the Polar ice cap.

If the bird had become lost, it could have followed open water and joined up with other gulls such as the Herring Gull before arriving in the North Sea.

Richard Fassnidge, site manager of the landfill, owned by Veolia Environmental Services, said: “Landfill sites are an unexpected source of biodiversity and we have seen many species at Rainham including Caspian, Iceland and Glaucous Gulls.

“My site team reported that Saturday was amazing – the slaty-backed gull resulted in the perimeter of the adjacent RSPB site becoming a virtual tourist destination!”