No one knows why they do it, yet each fall, thousands of starlings dance in the twilight above England and Scotland. The birds gather in shape-shifting flocks called murmurations, having migrated in the millions from Russia and Scandinavia to escape winter's frigid bite. Scientists aren't sure how they do it, either.
The starlings' murmurations are manifestations of swarm intelligence, which in different contexts is practised by schools of fish, swarms of bees, and colonies of ants. As far as I am aware, even complex algorithmic models haven't yet explained the starlings' aerobatics, which rely on the tiny birds' quicksilver reaction time of under 100 milliseconds, to avoid aerial collisions - and predators - in the giant flock. Despite their tour de force in the dusky sky, starlings have declined significantly in the UK in recent years, perhaps because of a decline in suitable nesting sites. The birds still roost in several of Britain's rural pastures, however, settling down to sleep, (and chatter), after their evening ballet.