Here, each spring and autumn, the skies come to life with the swirling displays of hundreds of thousands of starlings — an event known locally as “sort bol,” or “black sun” — as the birds pass through on their seasonal migrations.
Later, I extended the reach of my photographic investigation to include Rome, England, the Netherlands, Ireland and Catalonia, a region in northeastern Spain.
There is no single definitive explanation for why starlings murmurate, though most scientists theorize that the behavior helps protect the birds from predators. (Another possible explanation is that murmurations can help the starlings keep warm in the evening by recruiting larger roosts.) Moving in tandem as a single large entity both confuses predators and lowers the risk for each individual bird, a phenomenon called the “dilution effect.”
Most of the dramatic performances I witnessed occurred when one or more falcons or hawks were attacking the starling flocks.