Scandinavian starlings are known to winter in Southern Europe, however not all of them. When some fly as far south as Rome, or Athens, a decent number of tens and hundreds of thousands have fallen in love with Brighton Pier, and stay there throughout the entire winter.
Virtually, every night a plethora of plain dark-colored birds gather at the seaside and perform their gorgeous pre-roosting twirling dance oversea. And why do they do that, instead of going to sleep straight ahead? There is a thought that grouping together keeps starlings safe from predators such as falcons since it's hard to target one bird out of hypnotized flock of thousands. The birds also might gather to exchange information about good feeding areas as well as to keep warm at night.
Scientists are trying to find other explanations, but it seems to be inexplicable. And what are all those explanations needed for? It's beautiful, even without any scholarly remarks.
You may watch the spectacle at sunset all along the pier, starting from the last days of October through to the first days of March. Afterwards, the birds set off on their trip back home to Scandinavia.