Birdwatchers from all over Britain who gathered in Grimsby to catch sight of a rare American robin were horrified to see it eaten by a passing sparrowhawk.

They were still setting up their cameras when the predator swooped down from a row of drab factories and warehouses on an industrial estate.

The young bird, from the southern US, "didn't really live to enjoy her moment of fame," a twitcher told the Guardian.

The robin's vivid red breast made it an obvious candidate for a lunch date.

"It was a terrible moment," Graham Appleton, of the British Trust for Ornithology, which had spread news of the bird's arrival, told the newspaper.

Long-distance travels

But the trust's migration watch organiser Dawn Balmer was more philosophical.

"Most of these rare visitors eventually succumb anyway to cold weather or a lack of food, if not predation," she told the paper.

The robin, whose scientific name Turdus migratorius derives from its long-distance travels within America, was probably blown across the Atlantic after being "caught up in a jetstream", Mr Appleton added.

A member of the thrush family, with oily-black wings and tail, the American robin is as big as a British blackbird.