Starlings and their Murmurations
If you haven't seen before, starling flocks (murmurations) are quite a spectacle.
Hundreds or thousands of birds collect together before roosting for the night. It is unclear exactly why starlings flock like this. It has been suggested that larger numbers of birds mean warmer roosts during the winter months. The murmuration can be seen from a long distance off and so can attract other birds to join. It has also been thought that a flock provides safety from predation, as it is harder to single out individual birds to predate upon.
As the murmuration is such an interesting biological phenomenon, it has been used as a model system for science and research. The flocks display many interesting properties: