SACRAMENTO - When a flock of birds flutter their wings and take flight, creating beautiful pictures in the sky, it causes people to stop and stare.
Originally from Europe, the 8-inch, glossy black bird called the starling is the most often the bird responsible for the show-stopping display.
The starling is a very social bird that travels in flocks of hundreds to tens of thousands. It's a defense mechanism against birds of prey. The flocks create a dance in the sky, quickly shifting formation and expanding and contracting shapes.
When one starling changes speed or direction, they all follow simultaneously. The movement is called murmurations. Peregrine Fund Researcher Grainger Hunt said their doesn't seem to be one leader.
The flock tends to be more active just before sundown between autumn and spring.