Bruges has swans. Amsterdam has grey herons. Berlin has goshawks. Venice — not to mention every other European city — has feral pigeons in droves. And Paris has the house sparrow, a petite and exceptionally social bird famously well-suited to life in the big city.

To refer to the sparrow’s presence in Paris as ubiquitous would be an understatement. After all, this is the birthplace of the Little Sparrow herself, the legendary chanteuse Edith Giovanna Gassion. Piaf, a slang term for “sparrow” in French, was bestowed upon the diminutive singer as a nom de scène in the 1930s. Obviously, it stuck.

Simply, the house sparrow — passer domesticus — is everywhere in France's capital city yet, much like in London and several major urban areas across continental Europe including Hamburg and Prague, the bird’s numbers have been in rapid decline for well over a decade. As reported in 2006 by the Independent, in Paris alone, where house sparrows play an iconic “part of the identity of the city” and are known to be particularly tame, an estimated 200,000 birds — roughly 1 in 10 of the total population — had simply vanished within a 17-year time span.

At the time, French ornithologists were baffled. No single reason for the birds’ disappearance was offered but many possibilities were considered: air pollution, radio waves from cellphones and other mobile devices, an uptick in cat ownership among Parisians, the increased presence of “country” birds vying for valuable food sources and desirable nesting spots.

“Is it a question of some form of disease or diseases? Or are their habitats being eroded? We hope to try to answer these questions," Frédéric Baroteaux, an avian researcher with the Muséum d'Histoire Naturelle, remarked.

Sparrow In Paris In Paris, sparrows have long thrived on baguette-based hands-outs and neglected, nest-ready old buildings. The latter, it would seem, are becoming increasingly rare. (Photo: Petit Louis/flickr)

Ten years later, as the Parisian house sparrow population continues to plummet, it would seem that a definitive “why” has never been reached. But as CityLab’s Feargus O’Sullivan reports, the French media believes it has ID’d a top suspect: gentrification.

You see, true to their name, house sparrows like to nest in the exterior crevices and cavities of houses. But not just any old houses. Parisian house sparrows prefer run-down, shabby, Miss Havisham-y houses with ample nooks, crannies and extraneous ornamentation. The birds have a preference for historic structures that aren’t necessarily abandoned but could very well be falling apart. As for sleek, modernist structures? Non merci.

While many inner-city Parisian neighborhoods were once rife with such buildings, they’re quickly disappearing. Well, not disappearing entirely but being spruced-up and renovated by a new wave of homeowners, all anxious to sweep away the cobwebs and convert long-neglected garrets — primo house sparrow territory — into chic micro-apartments.

While there’s certainly nothing disagreeable with patching up windows and providing a neglected old apartment house with some long-overdue TLC, it’s been speculated that as upwardly mobile young Parisians begin to populate previously less desirable pockets of the city, longtime residents of the avian variety are being displaced — habitat loss by way of gentrification, essentially.

This headline published in free French daily newspaper 20 Minutes says it all:

“Paris: The number of sparrows, victims of gentrification, in accelerated fall”

Sparrows on the Seine While the decline of house sparrows throughout Paris is alarming, it's nothing like in London where the birds have all but disappeared completely. (Photo: ParisSharing/flickr)

Noting that the Parisian house sparrow population has dropped by more than 50 percent since 2010, 20 Minutes explains that the birds have become most notably scarce in the “quickly gentrifying, multicultural” 11th arrondissement, a densely populated neighborhood likened to New York City’s East Village in terms of “scale and sensibility” by the New York Times. Although popular with students and young professionals, the Times notes that the neighborhood remains “a little grittier and shabbier, less moneyed and touristy than other parts of town.” Translation: more house sparrow-friendly.

Across the Seine in the southwest of Paris, a dramatic reduction in house sparrows has also been noted in the previously sleepy working-class 15th arrondissement, now the most populous arrondissement in the city.

20 Minutes expounds on this “prime cause:”

… according to experts, sparrows could be especially victims of gentrification of the capital, which affected once popular districts like the 11th.

Indeed, 'the sparrow nests in a hole (...) he likes a bit dilapidated buildings, so when you renovate an old building, it removes habitat,' explains [president of the Ornithological Centre Ile-de-France] Frédéric Malher.

Over at CityLab, O’Sullivan notes that gentrification is an “entirely new culprit.” However, it was indeed hinted at a decade ago in the Independent: "…tightened building regulations, along with better maintenance, may have closed up the cracks in which they used to nest," wrote the paper.

sparrow grafitti in Paris While Paris does not recognize an official city bird, the common house sparrow - le moineau - fits the bills for all intents and purposes. (Photo: JeanneMenjoulet&Cie;/flickr)

Despite the headlines in French newspapers, O’Sullivan isn’t fully convinced that new money moving into inner-city neighborhoods can alone take the blame for Paris’ mysteriously disappearing house sparrows. Rather, their decline can be contributed to a number of things as previously hypothesized: air pollution, disappearing food sources and, last but not least, Marie, Berlioz, and Toulouse.

But although refurbishment has patched up some Parisian buildings, it has not obliterated eaves or guttering, and sparrows also nest in trees, on street lamps and illuminated billboards, among other sites. It’s more likely that new development of buildings with smooth-sided, eave-less walls and roofs is in part to blame, though even that alone could scarcely have a huge effect in the historic fabric of inner Paris. It’s probably safe to say that an epidemic of fixed-gear bikes and organic bakeries are not murdering the fluffy, defenseless birds of the French capital.

This all said, house sparrows are far from vanishing completely from Paris. Native Parisians and French ornithologists may have taken notice of the birds' decline but to others, particularly Londoners, Paris remains a veritable house sparrow paradise. Having previously written about their alarming — and never quite understood — exit from London in the 1990s, writer Michael McCarthy visited Paris in 2014 and was delighted to find the busy little birds flittering about pretty much everywhere.

He writes for the Independent:

For they greeted me the moment I walked out of Montparnasse station (I had come for a day trip from a Normandy holiday). I heard them cheeping as soon as I walked into the square outside (you always hear them first) and then saw three of them, as I set out on a systematic search of five likely locales. The first such was the Luxembourg Gardens, the lovely park not far from the Sorbonne; in a little patch of flower beds surrounded by bay hedges, near the Orangerie, I found a colony of about 30.

The next target was the Jardin des Plantes, Paris’s botanic garden, and I heard and saw them the moment I entered: they were hopping around people having picnics, hoping for crumbs. After that I tried the square in front of Notre Dame cathedral, packed with tourists, which I imagined would be sparrow-free, but to my surprise there were more than 100: you could hardly avoid them.

Then, on a hunch, I made for the pint-sized, charming park on the pointed end of the Île de La Cité in the middle of the Seine, which is called Le square du Vert Galant, and to my delight, they were there as well; and finally I went to the Tuileries, the long formal gardens between the Louvre and the Champs Elysees, and found a healthy colony by the café.

Parisians lamenting the absence of house sparrows in their own neighborhoods should no doubt grab a day-old baguette tout de suite and follow McCarthy's lead. And those who have recently purchased fixer-uppers in newly trendy neighborhoods and are about to embark on extensive home renovations, perhaps it would be wise to retain just a touch of decrepitude and dinginess.

Piaf would be most grateful.

Matt Hickman ( @mattyhick ) writes about design, architecture and the intersection between the natural world and the built environment.