IF YOU'VE SEEN ONE, you won’t soon forget it. Thousands of birds moving in undulating clouds, changing shape from moment to moment. Noisy and chaotic yet seemingly orchestrated, but how? You might have felt like the show was just for you—an ethereal rehearsal of a discordant philharmonic performed over a farm field for an audience of one. No two are the same, each one evoking wonder at forces of nature beyond our ken. Such are the murmurations of starlings.
Wildlife photographer and videographer Nick Dunlop lives for these experiences. For years, he has chronicled starling murmurations in his home state of California, preferring to work alone and keep his filming locations secret. He has a particular interest in the interplay between starlings and birds of prey, particularly peregrine falcons, who incite starling flocks to perform spectacular aerial maneuvers. Nick has kindly granted me permission to publish one of his photos and link to his video, “Starling-Falcon Dance,” which won an international competition in 2017 and was displayed at the Smithsonian Museum of Natural History in D.C. Watch this stunning example of what Nick calls “the rhythms of nature”.
Take a look at Nick Dunlop’s award-winning video, “The Starling-Falcon Dance,” and then return to continue reading about starling murmurations. If you’re on a laptop or desktop computer, we suggest you view it in full-screen mode. The video runs just under three minutes.
Starling murmurations occur in many parts of the country, including here on Cape Ann. As the cool temps of September give way to the first nips of fall, our local starlings are restless and beginning to form small flocks. Murmuration season is just around the corner. That such a commonplace bird—an invasive species no less—could be part of something so awe inspiring has puzzled nature lovers and scientists for centuries.
To begin to understand this phenomenon, we first need to know a little bit about starlings. The European starling (Sturnus vulgaris) is a raucous, aggressive, and gregarious bird a bit smaller than a robin with dark plumage that varies based on the age of a bird and the time of the year. During breeding season, adults sport light speckles amid purple and greenish hues, and a glossy, almost iridescent, sheen. If they weren’t regarded as pests, we’d probably be more impressed with their beauty.
Starlings were first successfully introduced to the U.S. in 1890 by a misguided literati who thought it would be a good idea to have every bird mentioned in the collective works of Shakespeare reside in the U.S. Owing to a single reference to starlings in Henry IV, Part I, he released 60 birds in Central Park. One hundred thirty years later, starling numbers have grown to over 200 million birds and their range has expanded throughout North America.
It’s not entirely clear how the collective noun “murmuration” as applied to starlings found its way into common usage. Frank Heppner, professor emeritus of biological sciences at the University of Rhode Island, has studied the flocking behavior of birds, including starlings, for his entire career, and he told me ornithologists didn’t use the term until recently. They simply referred to these events as “flocking behavior,” and specifically “cluster flocking” in the case of starlings vs. the “line formations” exhibited by ducks and geese.
The term “murmuration” may have some basis in literature, along with other colorful terms like “murder of crows” and “parliament of owls,” but that doesn’t explain its recent emergence. In 1968, the late James Lipton published a book, An Exaltation of Larks, in which many of these terms were first brought to popular attention. From that time forward, these collective nouns were popularized in crossword puzzles, Trivial Pursuit, “Jeopardy!”, and other late 20th century parlor games.
Murmuration is a particularly ill-suited label for starlings. “When I think of the verb ‘to murmur’,” Dr. Heppner said, “I think ‘to speak softly.’ Well that’s the last thing these birds do!” Very true. Starlings are capable of a wide and varied range of vocalizations. According to The Sibley Guide to Birds, individual starlings make the following sounds: “harsh rattling; thin, slurred whistles; a mushy, gurgling, hissing chatter with high, sliding whistles.” Multiply that by a few thousand birds in a flock, and you have an unholy racket.
Starlings are also mimics, not only of other birds but of many other sounds as well—from car alarms to barking dogs. And . . . they can talk! Yep, just like parrots. I spent 90 minutes I’ll never get back on YouTube watching videos of starlings holding forth in verse and song. My favorite: a tamed starling whistles Mozart ("Eine Kleine Natchmuzik"), then modulates to whistling “Dixie.”
So far you might think these birds sound pretty charming, so why are they considered an invasive species? “In general, invasive species don’t benefit the biomes they invade,” Dr. Heppner said, “so, their impact is mostly negative.” When starlings showed up on this side of the pond, they immediately began out-competing native bluebirds and woodpeckers for nesting sites (they are all cavity nesters). In addition, according to a report from the USDA, starlings cause hundreds of millions of dollars in crop damage (mainly to fruit trees) each year and may spread infectious diseases to humans and livestock. A flock of starlings was also responsible for the 1960 crash of an airplane at Logan Airport that killed 62 passengers. So, they have quite a rap sheet.
Starlings are invasive, but they are also an incredibly successful species, and they’re here to stay. I consider their flocking behavior a gift from an otherwise unlikely source. The most commonly asked question about murmurations is how the birds coordinate their flight without running into one another. Until the late 1980s, only biologists were interested in this question, but with progress in the field of computer modeling, other scientists—mathematicians, aeronautical engineers, physicists, computer scientists—started getting involved. In fact, early computer simulations based mostly on starling flocks made possible the realistic animations first used in Hollywood by Tim Burton in his 1992 film, Batman Returns.
More recently, use of stereoscopic cameras and 3D computer modeling have enabled researchers to identify rules of interaction among flocking starlings. They’ve discovered that the navigational choices of each individual bird are based on an awareness of its seven closest neighbors. There is no central organizing force, only the aggregation of hundreds, if not thousands, of these small groups adhering to the cues of their closest flying partners. The murmuration itself is an emergent property of smaller clusters of behavior.
Why they do this is a harder question. In a Darwinian sense, what is the selective advantage of engaging in such ostentatious group behavior? If these flocking patterns were mainly useful as a way to thwart predation, why would the birds engage in similar patterns for 20 or 30 minutes before roosting each evening? Such behavior would to seem to waste energy and attract predators. And that's one reason Dr. Heppner doesn’t believe predators have a significant impact on flocks as a whole. Another theory is that the birds use flocking as a way to assess population numbers and flock density, which may in turn regulate clutch sizes. There are still plenty of unknowns to investigate.
Over the next few months, keep an eye out for starlings, especially above the open fields along Southern Ave, Route 133, and Route 1A where they like to feed. If you have the good fortune to see a murmuration, the “hows” and “whys” of it will be quickly eclipsed by the primal rush of exhilaration you’ll feel from “what” you’re seeing. Nick Dunlop told me the birds always know he’s there. In that sense, you won’t be just watching; you’ll be a part of the show.