(Radio Iowa) – One of the sure signs of spring, Iowans are seeing huge congregations of birds filling the morning and evening skies, giant clouds of feathered creatures that often take several minutes to pass. Steve Dinsmore, a central Iowa ornithologist and bird watcher, says it’s typical during this time of the year to spot birds migrating in tremendously large numbers over Iowa. Those large undulating flocks are called a “murmuration” and may include tens of thousands of birds stretching over several miles.

Dinsmore, a professor of Natural Resource Ecology and Management at Iowa State University, says birds of a feather do flock together to avoid predators, plus, it offers information to the collective about good foraging or feeding sites. He says the murmurations are most likely starlings, blackbirds, redwing blackbirds or common grackles.