It’s a mesmerizing sight: Thousands of birds move in unison through the evening sky, whirling and swooping as if performing a highly synchronized ballet.

When they finally descend to their treetop roost, the beating of their iridescent wings creates such a rush of sound that the noise earned the phenomenon its unusual name: a murmuration of starlings.

The term is unique to European, or common starlings, one of the world’s most abundant—and adaptable—birds. Native to the United Kingdom as well as Europe, starlings have become invasive species throughout the U.S., Australia, New Zealand, Fiji, South Africa, and many other countries where, over centuries, they were introduced either by accident or