A friend of mine was recently traveling through Arizona, and while waiting out a flight delay at the Tucson airport, she wandered over to a tiny park jammed in between the rental car office and pickup garage. It had picnic tables, benches, small arbors, and even a water feature—so she did what any self-respecting birder would: looked for birds. If anything, she expected those most ubiquitous of urban birds: House Sparrows (the park was, after all, surrounded by concrete and jet noise). What she found was something else entirely: two Yellow-rumped Warblers foraging in a flowering bush, and, much to her surprise, a pair of Verdins busily constructing a nest in one of this mini-park’s little trees. She spent a fair bit of time enjoying their company, amazed at their ability to find succor in this rather depleted habitat.
It’s a story I’ve heard (and experienced) many times. Different species and different locations to be sure, but the theme is always the same: birds making a living in the unlikeliest of places, on the margins between the natural and constructed worlds. Peregrine Falcons are prime examples, able to thrive in the heart of the urban jungle, substituting skyscrapers for cliff ledges and making off with whatever prey presents itself (pigeons are favorite targets, and the falcons’ preference for these birds makes them very popular with city dwellers). Red-tailed Hawks have likewise found a place among humans—in some cases, attaining celebrity status (New York City’s Pale Male being perhaps the most famous). Ducks and geese are exceptionally good at making the most of the smallest of ponds. And gulls, pigeons, House Sparrows, Crows, and Starlings have all discovered the bounty offered by the detritus of our daily lives. But there are other, less obvious stories: Yellow-breasted Chats—Cardinal-sized warblers, highly secretive—show up in postage-stamp city parks; the flowered walkways outside New York’s American Museum of Natural History hosted a Rufous Hummingbird through one winter; and I know of an Ovenbird—a shy warbler of the forest floor—that spent part of the year in and around a city convenience store’s meager lawn.
These are somewhat extreme examples, but they are no means the only ones. Far from natural, many places we think of as ideal for birds are islands of habitat surrounded by harsh and inhospitable terrain. Arguably the most famous of these is Central Park, 843 acres of green set in Manhattan’s concrete core. To say that the park is good for birds is a gross understatement: on a normal day, it’s fantastic; during migration, it’s extraordinary. Warblers, orioles, blackbirds, tanagers, vireos—a host of species descend upon the park to feast on its bounty and shelter in its sylvan grounds. Birding here, it’s easy to get caught up in the extravaganza without questioning why it takes place. Take a look at a map of the city, though, and the reason is obvious: it’s one of the last, best naturescapes left in this vast metropolis. To birds exhausted by the trials of migration, Central Park offers sustenance and safety, a verdant oasis in an otherwise alien land—a margin, but on a grander scale.
Grandest of all margins, though, is the one that marks the boundary between earth and ocean. Here along the coast, where the land slips into the surf, are birds who push the notion of survival to the extreme. As a group, shorebirds undergo some of the longest migratory journeys—and longest non-stop flights—in the world. Most travel tens of thousands of miles each way, and sometimes stay aloft for days at a stretch—a feat that pushes endurance far beyond the reasonable; in addition to nearly doubling their weight before setting out, some birds, like Red Knots, Bar-tailed Godwits, and Sanderlings, digest muscle tissue and internal organs to carry them the distance. Those who break their journeys to rest and refuel (and some don’t) do so on beaches up and down the coast. For other birds, the beach represents migration’s end: American Oystercatchers, Least Terns, and Piping Plovers are among those who make their homes on the shore, nesting in depressions they dig out of the sand. But whether they pass through or settle down, these birds share something crucial: Beachfront property isn’t a luxury for them, it’s a necessity. And yet this narrow, vital edge is under constant siege, imperiling all who rely on it. The birds who survive here exist at a confluence of conflicts: the shifting balance between land and sea; development against conservation; political will versus ecological reality; and human want versus avian need. For now, they still persist—but they’re forced to do so on an ever-shrinking landscape, each vanishing piece taking with it another chance for the birds.
The capacity to exist on the margins, to find food and shelter on the edges of our lives, is a testament to birds’ knack for survival. But they can be pushed only so far. Every species has a breaking point past which it can no longer recover, a threshold that, once crossed, leads to a finality frightening to contemplate. Without care, sooner or later these margins may become too small to support the birds that depend on them, leading them down the path traveled by the Passenger Pigeon, Carolina Parakeet, Eskimo Curlew, Labrador Duck, and many others. Still, all is not yet lost. Birds can adapt, given adequate time to do so and enough open space to call home. But ultimately it’s up to us. Their fate is in our hands, and we must ask ourselves if we can find it in our hearts to make room for them, encourage their recovery, and champion their survival. A world rich with birds awaits us, if we only have the courage to create it and the wisdom to understand why.