Fascinating Flocks

One wintry day, I watch a small murmuration of starlings swoop up with a whoosh to my bare apple tree en masse, then fly to the ground. These birds are an introduced species from Europe, where they form leaderless, massive flocks in the hundreds of thousands,
sweeping the sky, shifting on a dime and changing shapes in an instant. Onlookers are stunned, observing this aerial display.

Starlings amass for protection against predators, such as the peregrine falcon. As their field of vision does not allow for forward or backward sight, each one relies on the birds immediately adjacent, following shifts in an instant.

During migration season, we have the opportunity to watch various species feed and depart. Our colorful springtime nesting and breeding barn swallows travel south in the winter, during the day, in disorganized and unwieldy groups.

Killdeer gather in much larger groups to forage intently for weight gain on their move south. In the breeding season, they are in mated pairs, with few others in their territory. And, of course, some of our Canadian geese depart in V formations, creating their haunting calls as they soar.

Here in Massachusetts, we have a yearly winter phenomenon in Lawrence, an old mill town bordering the Merrimack River. I have read about large numbers of American and fish crows gathering to roost for the night after foraging, sometimes from as far as 50 miles away. They gather for protection, warmth, and perhaps communication about feeding opportunities. This is their wintering area as they migrate from the north.

First, they arrive in small groups at staging trees near the river. At dusk, they form a stream just above the water, traveling to roost for the night. Even though there are large numbers of birds, they are difficult to find.

For several years, my late partner and I went to Lawrence at dusk, to no avail. One year, we watched a few crows moving in the same direction and headed over to a small parking lot next to a group of stores. There we had the serendipitous opportunity to meet a couple who had been researching this event for years, taking careful notes on locations and numbers. They graciously suggested we follow them in our car, as every night the staging is in a different place, probably to foil predators. To make matters more difficult, they also change the roost area.

After searching the vicinity, we followed them to a parking lot where thousands of crows appeared, creating a deafening cacophony. They perched for a while and flew off, vocalizing loudly. I was so glad that persistence in this quest finally paid off my head tilting upward as the sky turned black. The din still remains unforgettable. Our researchers have counted 14,000 crows tonight!

We have been graced with a spectacular event so close to home. Nature is all around us: our towns, cities, and suburbs. If we choose to be aware, we can be rewarded with unexpected and satisfying sights and sounds. As citizen scientists, direct observation also makes us experts on what we experience.