FLIGHT PATTERNS

Thousands of birds turn as one in a vast, surging, rippling, rolling dance across the sky — a ballet choreographed by nature. A murmuration.

“Murmuration” is a word usually heard in relation to starlings. In their case, the word not only describes the mesmerizing dusk-hours event we may be lucky enough to witness, but also serves as a collective noun: A murmuration of starlings is akin to an exaltation of larks, a wisdom of owls, a murder of crows, a piteousness of doves or a cloud of yellow-headed blackbirds. But the word can also apply to any large mass of birds moving like some quivering, dark cloud across heaven. The behavior is considered a flock approach to safety: You’re less likely to be eaten if you’re one of thousands. The term comes from the Latin word murmuratio, which means murmuring or grumbling. Certainly, the low, continuous sounds emanating from thousands of birds moving in chorus against the dusk could be considered a murmuring.

The sounds of a murmuration of yellow-headed blackbirds, however, might have a different quality. According to my Audubon field guide, these blackbirds’ males “may have the worst song of any North American bird.” A hoarse, harsh scraping sound, it is frequently described as “a rusty farm gate opening.”
 

Voice aside, male yellow-headed blackbirds are quite dapper, with their yellow heads and breasts and white patches at the bend in their jet-black wings. In any case, they seem to have no problem attracting females, forming breeding partnerships simultaneously with more than one. Because their natural habit is marshland, an environment rich in food, these guys have it made. A male may help the first of his mates in gathering food, but he leaves the others to fend for themselves in territory where that is doable. (At least 90 percent of bird species are monogamous, most likely because less-rich habitats require two parents to successfully raise the young.) While there are animals and birds that prey on yellow-headed blackbirds’ eggs, this species is essentially secure throughout most of its breeding and wintering range — Canadian prairies south through Arizona and Mexico — the prime threats being disappearing wetlands and pesticides in farm fields that provide winter forage.

The mystery in the murmuration is how that many birds manage to move in unison, all turning in the same waves and swirls, the same moment, the whole of the flock seeming to be a single organism, its flow the product of one mind, one determination, one sense of sky. In fact, the synchronization is accomplished via the ability of each bird to pay attention to its immediately surrounding six or seven neighbors — moving as they move, turning, rising, descending as those birds do.

Does this knowledge interfere with the wonder of the murmuration, or enhance it? The gigantic flock explodes out of the earth. It bends and folds across the sky like some colossal scarf of the gods. A ballet? Maybe. An act of life? Absolutely.