Gretna

Hurricane Isaac sidestepped New Orleans on Wednesday, sending the worst of its howling wind and heavy rain into a cluster of rural fishing villages that had few defenses against the slow-moving storm that could bring days of unending rain. Isaac arrived exactly seven years after Hurricane Katrina and passed slightly to the west of New [...]

No one knows why they do it. Yet each fall, thousands of starlings dance in the twilight above Gretna, Scotland. The birds gather in magical shape-shifting flocks called murmurations, having migrated in the millions from Russia and Scandinavia to escape winter’s bite. Scientists aren’t sure how they do it, either. Even complex algorithmic models haven’t yet explained the starlings’ acrobatics, which rely on the tiny bird’s quicksilver reaction time of under 100 milliseconds to avoid aerial collisions—and predators—in the giant flock. Despite their show of force in the dusky sky, starlings have declined significantly in the UK in recent years, perhaps because of a drop in nesting sites. The birds still roost in several of Britain’s rural pastures, however, settling down to sleep (and chatter) after the evening’s ballet.

Sonia van Gilder Cooke is a reporter in TIME’s London Bureau. Follow her on Twitter at @svangildercooke.