This is a description of a thing of noble beauty, the sort of creature you might find on a family crest, a bird to inspire religious metaphors. And in fact it has: For most of history there was no distinction between (scruffy) pigeons and (iconic) doves. That bird that brought Noah, while on the ark, the first sign of dry land? If you go back to the Hebrew, the word for that bird actually translates to “of the pigeon type.” But at some point people began thinking of doves and pigeons differently. They are all in the same family—it’s just that somewhere along the line certain species arbitrarily acquired the common name “dove,” while others got called “pigeon.” Some got both: Columba palumbus has been called both a “ring dove” and a “wood pigeon.” In her book Superdove, Courtney Humphries suggests that it was Shakespeare that solidified the division between pigeons and doves. In Shakespeare’s work, pigeons always play a functional role, while the parts for doves are consistently symbolic. The dove is “equated with peace, modesty, patience, love and other noble ideals.” The pigeon usually just shows up on a dinner plate. The dove is metaphoric, the pigeon is mundane. And this division has stuck, Humphries writes: “We never talk of pigeons of peace or dove droppings on statues. ‘Dove’ is a pleasant enough title to grace chocolate bars and soap, while ‘pigeon’ has no marketing appeal.” Imagine if John the Baptist had said he saw the Holy Spirit descending to Jesus “like a pigeon.”
But if you are interested in getting past the marketing appeal, past the flash and dazzle of meanings we’ve imposed upon nature, and instead simply seeing nature, the pigeon is a great place to start. Has any other creature lived so closely with us, while so successfully avoiding the romantic varnish of human imagination?
As I read on, still seeking the solution to the mystery of the ugly feet but pleasantly diverted, I saw what I always see when confronted with the reality of the living world: Unvarnished nature is far more wondrous than our romantic artifice.
FAMILY VALUES
If you start watching pigeons, one of the first things you’ll notice is that you never see a chick. Like some mythical beast, these birds reveal themselves to humans only after reaching maturity. There are two good reasons for this: First, pigeons are good at hiding their nests; and second, the young birds—called squabs—stay in the nest until they lose the obvious indicators of youth.
They are able to do this because mother and father pigeon work together to provide for their young. This equality in parenting extends to milk production: Both males and females secrete a cheesy yellow milk into the crop, a food-storage pouch partway down the throat. I had thought that milk belonged exclusively to mammals; it’s our defining characteristic, so important that we are named for it—“mammal” comes from the Latin mamma, meaning breast. Pigeons are more closely related to dinosaurs than mammals. Like breast milk, pigeon milk contains antibodies and immune-system regulators. Like breast milk, it is stimulated by the hormone prolactin; in fact, scientists discovered prolactin while studying pigeons. Despite the similarities, mammal milk isn’t a relative of pigeon milk. Instead, it is an example of convergent evolution: a strikingly similar trait that arose independently in different branches of the tree of life.
As milk scientist Katie Hinde has written on her blog, Mammels Suck: “The production of milk independently arose after the divergence of avian and mammalian lineages over 300 million years ago. However, these milks seemingly serve the same function: body-nourishing, bacteria-inoculating, immune-programming substances produced by parents specifically to support offspring development.”
Milk, in other words, is so useful that evolution created it twice.
Pigeon milk has much more protein, and much less sugar and fat, than human milk. On this diet, young pigeons often double their weight in a single day. The squabs stick their heads into their parents’ mouths, thrust vigorously, and suck up a regurgitated meal. They do this for two months, after which they are relatively mature. Many other bird species leave the nest after just two or three weeks.
There are a few characteristics that distinguish a juvenile pigeon. You can look for an oversized beak—it takes them a while to grow into it—or for a pinkish-gray blob of skin where the beak meets the head; this cere turns white as they mature. But the most salient clue is the color of the eyes: Juveniles have brown eyes, whereas adult pigeons have shockingly bright, reddish-orange eyes, another of those extraordinary details I’d never noticed until I started looking for it.
The other reason you’re unlikely to see young pigeons is that the nests are hidden. Pigeons were originally cliff-dwelling birds, seeking out caves in rock faces. In cities, they do much the same: The perfect pigeon-nesting location might be an abandoned apartment halfway up an old building, or a new one; workers often find pigeon nests in partially completed towers. They like to squeeze into cavelike sanctuaries protected from the weather and predators, with a flat floor to keep eggs from rolling away.
Though pigeons masterfully hide their homes, they are terrible at building them. Often, a nest consists of no more than a few twigs haphazardly arranged on a flat surface. “Most pigeons surely do not qualify as master architects,” Johnston wrote. Unlike the birds that do qualify for this title—the swallows and Baya weavers, which suspend their nests from undersurfaces—pigeons that nest on narrow ledges sometimes send eggs plummeting to the pavement below.
Pigeon nests build up over time, because the birds return to the same spot. With each laying, the parents add a few twigs, but the bulk of each nest seems to consist mostly of the birds themselves. And this, if crop milk hasn’t already induced nausea, is where it gets gross. The young back up to the edge of the nest and poop off the side, building up a rim of guano. A healthy pair of pigeons can lay six times a year—two eggs each time—and after few years, all those pooping pigeons can solidify a nest into a heavy plinth. Johnston found one nest that weighed four and a half pounds and contained several crushed eggs and two “mummified young.” He characterized such structures as “monumental in size and longevity.” We humans have the pyramids, the Arc de Triomphe, and Mount Rushmore; pigeons have piles of sticks and dead babies encased in poop. These pigeon monuments may harbor mite and insect populations, but also discourage the worst ectoparasites, like fleas, Johnston wrote. My notes on Johnston’s nest findings end with an editorial annotation: “glahaahg.”
AN EXPEDITION TO PIGEON HABITAT
It’s counterintuitive, but the more repellant tidbits I gathered about pigeons, the more closely I wanted to look. For one thing, I wanted to examine their feet. I’d found so little on mangled feet in the scientific literature that I began to wonder if I was exaggerating the problem. I also wanted to inspect the birds afresh, so that I might see the colors and patterns and behaviors that I had been so astonished to discover. And so, on an Easter Sunday, while many kids were dyeing eggs and eating chocolate, I took my two-year-old daughter on a pigeon expedition. When I had told my plan to my wife, Beth, she blanched. Where exactly, she wanted to know, did I plan on going? “Will you please be sure to keep our daughter away from human feces and needles?” she asked.
It was a reasonable request: Pigeons prefer dense urban settings, and they congregate in open spaces. It’s exactly the same environment favored by the mentally ill, drug addicts, and homeless people. I suspect that some of the disgust we feel for pigeons is associative. We’ve grafted our feelings about human outcasts onto these birds because they share the same spaces and hang around waiting for handouts. Perhaps we’d feel differently about pigeons if we were better at dealing with our own species.
Josephine, however, was delighted to be setting out on the expedition. As we waited for the morning train, I plumbed her knowledge of pigeons.
They are, she told me, “white.”
Okay, any other colors? “Black.”
“What do they do?”
“Fly.” She demonstrated, one pudgy hand flapping a diagonal line from her chest to over her head. That pretty much exhausted her comprehension.
When we emerged at the San Francisco Embarcadero, Josephine got out of her stroller and ran the blocks to the waterfront, past the street artists and knickknack sellers setting up their booths. She’d promised to alert me when she saw her first bird, but she toddled past one bobbing along the concrete, and then another. Finally I knelt and wrapped an arm around her to halt her momentum. Still, she looked past the birds. I extended one arm at her eye level and pointed them out: two healthy-looking creatures strutting between an empty coffee cup and a sheet of newspaper. She drew in a breath, as if we’d spotted a condor.
“What do you see?” I asked, alert for her first, unsullied impressions.
“Pigeons” was her less-than-satisfactory response. What did I expect from a two-year-old? An inspiring quote? An original biological observation? She leaned against my restraining arm, her warm body straining toward movement.
I made one last stab: “What colors?”
“Black and white,” she said matter-of-factly, then added, “and green.”
And there it was: The iridescence of their neck feathers shone green on top, and purple on the undersides of their necks. I’d never registered the greenness of pigeons, and interestingly, none of the formal descriptions I’d read had noted it either. And yet Jo, in her first few seconds of work as a young naturalist, had made this discovery effortlessly. Of course, she wasn’t the first; when I went back to the library I found other descriptions that did mention green. The material of the neck feathers works as a crude mirror, and tiny barbs align in such a way as to cast shimmering light that shifts with movement. Pigeon necks look even more fabulous to pigeons: They see in a broader spectrum of light than people, so in addition to the colors we perceive, pigeons see two additional colors in the ultraviolet wavelengths that we, poor limited beings that we are, will never comprehend.
When Josephine said pigeons were black and white, I assumed she meant black and a color much lighter than black whose name she had forgotten (i.e., gray). But some of the pigeons in the plaza that morning were also splashed with white. When white “doves” are released—such as at a wedding or a grand opening—they are almost always actually king pigeons, a breed with white plumage. These white birds find their way into feral groups, splattering white paint on feathers across the clan for generations.
Beyond iridescence, pigeons have just three feather pigments: black, white, and rusty brown. These are combined in three main wing patterns: bar, which is the classic pigeon look, with an armband on each wing; spread, which is essentially all black; and check, in which black and white form a crazy quilt on the wings. Much more rare are the reds, which are really a hue of light brown. These mix together in infinite combinations.
The Importance of Absurd Pigeons
Pigeon colors are important because the human fascination with the genetic determinants of pigeon plumage underpins the entirety of modern biology. It wouldn’t be too much of a stretch to say that pigeons are responsible for our understanding of evolution—the master theory that governs the modern understanding of life.
Breeders have refined pigeon genetics to preposterous extremes. In her pigeon book, Humphries dreamed up instructions for visualizing some of these fancy show breeds: “Pouter: Squeeze the pigeon from its lower half like toothpaste, until its body is skinny and its breast puffs up. Then pull its legs until they are twice as long as normal pigeon legs. Stand upright. . . . Fantail: Affix a large turkey tail to the back of a pigeon. Because the tail will be too heavy, give the bird an enormous breast to compensate and move its head onto its back.” Another breed, Modenas, are, according to her whimsy, “voluptuous bird pillows.”
The point is that humans have figured out how to mold this species into just about anything. The genetic rules that govern pigeons are complex, but pigeon breeders developed folk knowledge that comprehended recessive characteristics, sex-linked attributes, trait suppression, and other principles long before the time of Gregor Mendel or Charles Darwin. Much of Darwin’s theory of evolution, in fact, comes from observing the techniques of pigeon breeders. Most of the first chapter of On the Origin of Species is about pigeons. His editor actually suggested he chuck the rest and focus on the birds: “Everyone is interested in pigeons,” he told Darwin. It makes a better Hollywood story to say that Darwin’s revelations came as epiphanies in strange lands, but he really made most of his discoveries at home. On the Beagle he made some acute observations of finches, but it wasn’t until Darwin made a close examination of the utterly unexotic pigeons of England that he was able to articulate a detailed mechanism explaining how evolution worked. In a very real way, the folk knowledge of pigeon fanciers is the foundation of our understanding of biology.
How High-Class Birds Became Low-Class Sky Rats
Josephine zigzagged through Justin Herman Plaza honing her curb-walking skills and pointing occasionally to a pigeon. I chased after her, bouncing the stroller down steps, then back up again when she circled around. A beautifully ugly fountain—a knot of ragged concrete pipes that are almost always dry—dominates the plaza. Unshaven, smudge-faced men napped on the grass. It’s stark, but it’s surrounded on all sides by postcard-perfect scenery. Along the street stand rows of palm trees, interrupted by the clock tower of the San Francisco Ferry Building. Beyond lies the bay, and on that day dozens of white sailboats ironed the water’s chop. Justin Herman Plaza is a working-class retort (or un-working-class, more properly) to the upper-class waterfront. And of course, that makes it pigeon habitat. Perhaps a dozen loafed atop the pockmarked fountain.
There are people who love pigeons for their association with the downtrodden. The rapper Vast Aire, who casts himself as a pigeon in one of his songs, explained the affinity: “They are at the bottom of the food chain, but they still survive, they still make it.”
Many of the people who regularly feed and cultivate relationships with pigeons are themselves on the fringes of society. They are disconnected from other people due to poverty, limited language skills, or mental illness, but they form deep emotional connections with the birds.
Before pigeons were symbols of poverty, they were gentrified. They were spread around the world by aristocrats. Before we started designing architectural features to repel pigeons, the upper class built nesting places in their houses to invite them in. The French colonial governor of Quebec, Samuel de Champlain, brought pigeons to the New World and had the workmen include a roost in his home. Every city pigeon now scrounging for crumbs is a descendant of these birds cultivated by the gentry.
How does one fall from a position as a symbol of affluence to a symbol of indigence? I suspect that the pigeon’s status is inversely related to its biological success. That is, pigeons could not very well serve as a marker of nobility once they became, well, common. Aristocracy demands exclusivity.
If there weren’t such an abundance of wild pigeons, they might have maintained their social position, because no one was ever able to truly industrialize pigeon farming. Unlike the mass-production-ready chicken, pigeons spend a lot of time nurturing their offspring—the parents nurse the young squabs for three months. That’s why pigeons on the plate retained their exclusivity: They never became a commoner’s meal.
As Europeans spread across North America they left behind a trail of pigeons. By putting up statues and courthouses and laying out public plazas, they created the habitat pigeons needed to multiply. When it became commonplace, the species turned into a humble bird of the people.
We’re left with an incoherent double standard: We despise the bird in its impoverished feral state, but savor it on the menu. Most restaurateurs do their best to help us keep these two versions of the bird separate. However, there is one upscale poultry shop in Amsterdam called Pieter van Meel Groothandel in Wild en Gevogelte that makes pâté from the wild pigeons of the city. One of the shop’s owners, Thomas van Meel, confirmed via e-mail that he makes “game pâté” from urban pigeons, but only after screening the birds for disease. Imagine a world in which we
saw pigeons not as objects of disgust, but as a sustainable local food source.
Close Encounters of the Bird Kind
As pigeons were making their descent from bird of the aristocracy to bird of poverty, the native American passenger pigeon was going extinct. The paved habitat that allowed pigeons to spread was replacing the forest habitat that had supported passenger pigeons. We traded a bird of the trees for a bird of the city.
Feral pigeons truly are the people’s bird in that they depend on us, and in a sense, they belong to us. Humans are an essential element in most ecosystems that support pigeons. There are a few wild places, like the coastal cliffs of Sardinia, where populations of pigeons remain, but even those birds forage for seeds from farms. In places abandoned by humans, like the Scottish island of St. Kilda, the pigeons have gone extinct. To idealistic naturalists of the old school, who only value nature when the human touch is undetectable, this dependency makes pigeons uninteresting at best. The original pigeon sin is that they allied themselves with humans as we tried to improve upon Eden. They thrive in our litter-strewn wake. We see our own scrappy, invasive nature reflected in pigeons, and it horrifies us.
Or maybe not. There’s a simpler way to explain the revulsion pigeons provoke than claiming we see our reflection in their beady red eyes. Maybe what really horrifies us about pigeons is that they truly can be fecking disgusting.
Unseen City Page 3