Language is an instrument of great precision and poignancy — our best tool for telling each other what the world is and what we are, for conveying the blueness of blue and the wonder of being alive. But it is also a thing of great pliancy and creativity — a living reminder that how we name things changes what we see, changes the seer. (This, of course, is why we have poetry.) It is the birthplace of the imagination and forever its plaything: I remember my unabashed delight when a naturalist friend first introduced me to the various terms for groups of birds — from “a deceit of lapwings” to “a pitying of turtledoves,” and could there be a notion more charming than “an ostentation of peacocks”?

Some of these collective nouns, often called company terms, are based on observable characteristics of the species — “a fall of woodcock” references the bewildering air dance of the courting birds, “a watch of nightingales” pays homage to the nocturnal wakefulness of Earth’s most musical bird, and “a gaggle of geese” turns their migratory cries into delicious onomatopoeia. Some stem from myths and folk beliefs about birds dating back centuries, to a time when Satan was realer than gravity in the human mind, Kepler’s mother could be tried for witchcraft, and superstition was the primary sensemaking tool for causality — an organizing principle for life, reflected in language: “a murder of crows” alludes to various superstitions about crows as emissaries of death, believed capable of killing their own kind in punishment for transgression; “a parliament of owls” draws on ancient Greek mythology, in which an owl accompanies Athena — the goddess of wisdom and reason, representing freedom and democracy across the Western world.

A great many of these company terms originate in one of the first books printed in English after the invention of the Gutenberg Press: the Boke of Seynt Albans [Book of Saint Albans], also known as The Book of Hawking, Hunting, and Blasing of Arms. Anonymously published in 1486 and written largely in verse, it was lauded as the work of “a gentleman of excellent gifts” — until it was discovered that the author was a woman named Juliana Barnes.

Like Sor Juana two centuries later, Juliana had suffered some great unnamed heartbreak that led her to retreat to a cloister, where she immersed herself in study — convents were often the only way women could access books in an era when formal education was entirely closed to them. Like Montaigne, she became a prolific diarist. Having refined herself as a writer on these private pages, she began writing for the public — an act of tremendous courage and confidence for a woman in the fifteenth century to begin with, and doubly so given she chose to write about masculine endeavors: hunting, fishing, hawking.

Tucked into the middle of her book is a long list of company terms under the heading “THE COMPAYNYS OF BEESTYS AND FOWLYS.” Discernible through the confounding Old English, through the bastarda blackletter script barely legible to modern eyes, are the charming “exaltation of larks” (Exaltyng of Larkis), “murmuration of starlings” (Murmuration of Stares), “watch of nightingales” (Wache of Nyghtingalis), “sedge of herons” (Sege of heronnys), “gaggle of geese” (Gagle of gees), and “unkindness of ravens” (unkyndenes of Ravenes), all still in use today.

Half a millennium after Juliana Barnes died an unknown nun in an English convent on a planet without clocks, calculus, or democracy that thought itself the center of the universe, the English painter and children’s book illustrator Brian Wildsmith (January 22, 1930–August 31, 2016) brought to life the loveliest of these company terms in the 1967 gem Birds by Brian Wildsmith (public library).

Not all of these terms have remained the same across space and time — different eras and different regions have devised their own strange and wondrous lexicon for the same bird groupings. Juliana Barnes’s “sedge of herons” gave way to the “siege of herons” more popular today, shifting focus from the silent silhouettes of these dignified birds rising from the edge of the pond like tall grass to the inelegant and rather violent-sounding vocalizations they make during flight; in Wildsmith’s painted aviary owls are not a “parliament” but a “stare,” the term now brinking on the obsolete, having peaked in use the year before the book was published.

Emerging from these changing terms is a testament to Toni Morrison’s insistence that language is best understood “partly as a system, partly as a living thing” — evidence that language is but a microcosm of life, subject to its own evolutionary forces of adaptation to context akin to those that transformed the dinosaurs into birds. Lest we forget, words too face the peril of extinction.

Complement with the fascinating science of the owl sensorium and some stunning centuries-old illustrations of birds of paradise — which, if they moved in groups, deserve the company term “constellation” — then revisit the story of how the clouds, those eternal companions of the birds, got their names.