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  • More glass equals more bird fatalities


    Humans celebrate birds—bird-watching is now more popular than golf and even gardening—but North American buildings may kill close to a billion each year.

     

    PLANS BY TELUS TO TRANSFORM Victoria’s downtown with “an iconic architectural landmark” featuring a massive, 11-storey high wall of glass on lower Douglas Street are generating a robust conversation about environmentally sustainable development.

    On the face of it, the planners set out admirable objectives: the structure is to bolster biodiversity with “lush tree canopies,” “pollinator eco-systems,” and a slew of other concepts from the green mission statement word hoard—low carbon compliance, rainwater harvesting, carbon sequestration, deep operational carbon emission control, renewable power generation through solar panels and so on.

    Of course, it’s not the only new building coming to Victoria. There’s been discussion about plans for a dramatic 20-storey flatiron structure at Fort and Blanshard which, as envisioned, would need a variance to exceed height restrictions by six metres. 

    I’m all for imaginative iconic architecture. I’m certainly not obsessive about preserving stodgy, pervasive colonial symbols that emulate and evoke historic connections to Victoria’s unsavoury past as the seat of power for imposing systematic, anti-democratic, cultural oppression. But some aspects of the proposed projects do give pause. 

     

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    Can the planned Telus Ocean be bird-friendly?

     

    There’s that enthusiastically endorsed “wall of glass,” for one thing. Architects have been mesmerized by the aesthetic possibilities of transparency and reflective cladding surfaces for half a century now, ever since a revolution in the properties of building envelope materials made immense glass towers a reality. Our embrace of glass is understandable: it’s beauty, however, poses profound problems for birds. 

    Many years ago, in a distant city, I’d walk silent streets in the predawn gloom, passing among the nondescript brick walkups and grimy business low-rise business fronts until I crested a slight rise. Suddenly before me, on the other side of the deep river valley that bisected that city—just as the earliest birds greeted the world with their dawn chorus—I’d see the recently arisen, luminous, 40-storey pillars of glass that comprised the urban core. 

    I loved the sound of the early birds calling from gardens and from the forested parklands of the valley and I loved the stunning visual impact in that first sight of the city erupting from the still-dark northern horizon. 

    Stacked against the black heavens, those skyscrapers rising above the commercial district at their base never failed to make me pause in their eerie glow and to stare at the stark, unpardonable beauty of that manufactured landscape. Some towers were suffused with a warm, golden incandescence; some glittered with internal light as hard as diamonds; yet others were pillars of pale emerald or a faint aquamarine. Red warning lights blinked above them. Neon signs splashed colour. Traffic lights blipped through their endless cycles of amber, red, green. Headlights from the occasional taxi jittered through the windy canyons of steel, glass and concrete.

    I always felt a bit special at the sight, as though I’d been allowed in for a private, personal viewing of some vast kinetic art installation. 

    Never once did it cross my mind that I was also looking at a gigantic, mindless killing machine that threatened the existence of my other source of beauty in that moment—the untutored, spontaneous symphony of wild birdsong.

     

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    A hawk colliding with a building. Photograph by Deborah Allen

     

    But a killing machine that built urban landscape was and still remains. An annihilation machine, ruthlessly efficient, entirely heedless, constructed for our convenience at the immense expense of the feathered species that we celebrate as spiritual envoys from nature and as symbols of freedom unfettered by, as the poet once put it, “the surly bonds of earth.”   

    The billions of windows in millions of residential buildings in Canada and the United States, the display glass of commercial buildings, the aesthetically-pleasing glass towers whose possibilities inspire architectural imaginations, are estimated by some scientists to kill close to a billion birds a year. Attracted into the urban landscape by the habitation glow that encompasses every human settlement in developed economies, birds in flight collide with glass that’s invisible to them. The meeting is almost always fatal.

     

    Bird-friendly design not top of mind in Victoria

    “Unlike humans, birds cannot perceive images reflected in glass as reflections and will fly into windows that appear to be trees or sky,” observes a report for the Fatal Light Awareness Program (FLAP) in Toronto, a city-wide initiative which has been grappling with the problem.

    “Clear glass also poses a danger as birds have no natural ability to perceive clear glass as a solid object. Birds will strike clear glass while attempting to reach habitat and sky seen through corridors, windows positioned opposite each other in a room, ground floor lobbies, glass balconies or glass corners. The impact of striking a reflective or clear window in full flight often results in death.

    “Experiments suggest that bird collisions with windows are indiscriminate. They can occur anywhere, at any time, day or night, year-round, across urban and rural landscapes, affecting migratory, resident, young, old, large, small, male and female birds.”

     

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    Flat glass panels are especially dangerous for birds. Photograph by John McHugh, Creative Commons via Wikimedia Commons

     

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    FLAP hosts an annual dead bird layout to raise awareness about the dangers birds face in our built environment. Photo by Leighton Jones

     

    The concerned municipal planners and building envelope experts in Toronto point out in the report that the amount of glass in a building is the single strongest predictor of how dangerous it is to birds. As changes in production and construction techniques facilitated the greater use of glass, they note, cities have become ever-more dangerous for birds to navigate.

    “Today it is now common to see buildings with the appearance of complete glass exteriors. The increase of curtain wall and window wall glazing, as well as picture windows on private homes, has in turn increased the incidence of bird collisions. Today, the vast majority of Toronto’s new mid-to-high rise buildings contain more than 60 percent glass.”

    Developers of the Telus Ocean building appear to have committed from the outset to active exploration of mitigation strategies ranging from glass cladding modified to make it visible to birds, to the use of screens, latticework and louvres.

    Glass adjacent to vegetation is to be treated with elements that are visible only to birds, says a revised design submitted to the City late last year.

    And exterior and interior plantings are to be given “careful consideration” regarding location to reduce both the appeal of interior spaces to birds and possible confusion about available perches for birds in flight.  There are also plans to reduce nighttime illumination that might prove hazardous to migrating birds.

    Although mitigation strategies like those outlined in the Telus Ocean application are both commendable and welcomed by environmentalists concerned about urban bird strikes, the overall magnitude of the problem remains immense.

    One concerned group, the Victoria Bird Strike Initiative wrote last November to regional municipalities urging them to pass bylaws mandating design to mitigate bird strikes as a required part of the application process for new buildings. The letter claimed North America has lost almost one-third of its bird population since 1970.

    Erin Dlabola, a former employee of the University of Victoria who said over a hundred dead birds had been found around only a few buildings on the campus, asked regional governments to get proactive about mandating design features that can substantially reduce fatal bird collisions.

    “When bird-friendly design is incorporated at the planning stage, it can be cost neutral, and complement other design goals like energy efficiency,” wrote Dlabola and co-campaigner Willow English. “In addition, there are ways to make existing buildings safer for birds using visual markers and other products and techniques.”

    “Those [municipalities] who responded were mostly positive,” Dlabola says. “A few municipalities we heard back from already had plans to implement bird-friendly design guidelines in upcoming community plans and or bylaws and it was good to see there was already awareness on this issue.

    “Next we would like to see bird-friendly guidelines mandated by municipalities because it is the most effective solution based on guidelines that have been implemented in other cities.”

    English said that in the City of Victoria, however, “the current wording of the design guidelines is not stringent enough to ensure that new buildings are bird friendly.

    “Of particular concern is the text encouraging large areas of transparent glass at ground level, and only asking for bird collisions to be considered on higher storeys. Most bird collisions occur within the first four storeys of a building, making this area the most important for bird-friendly design.”  

    Ploughing through the City’s design plan guidelines, official community plans and other documents, however, doesn’t yield much in the way of easily discernible or rigorously expressed policy vision about what needs to be done to assertively address the problem.

    Search city websites in Toronto, Calgary, Ottawa or Vancouver and the issue is clearly top-of-the-mind for urban planners and developers alike. Search Victoria’s documents and bird-friendly design prescriptions are extraordinarily difficult to find—that’s a clear statement of priorities in itself.

    Indeed, do a web search for urban bicycle policy in Victoria and you are inundated with hits. Do the same thing for bird-friendly design, nothing, at least not in the first five search pages—another statement of priorities that seems odd in a city that often bills itself as one of the greenest in Canada.  

     

    And yet, we love birds more than ever

    Let’s extend that mind-boggling billion bird collision fatalities a bit. 

    The highest estimate would mean that since the turn of this century, in Canada and the US alone, about 20 billion birds have perished crashing into the entirely passive threat of windows they can’t see. To that colossal number, you can add another 10 billion killed by domestic and feral cats. Then there are the 3.5 billion birds killed by high tension electrical wires, the 1.5 billion killed by pesticides and rodent poisons and the 1.2 billion killed by cars. Add it all up and so far this century you get 36.5 billion birds killed by unwitting and unintentional human activity. More than half of those fatalities are caused by windows.

    Other numbers suggest that quite contrary to the dolorous reality of human-caused bird fatalities, most of us—ironically—appear to love the birds we destroy by the billion. 

    Business and market statistics show that since the pandemic began, householders trapped at home by lockdowns have turned to the winged wildlife just outside their death-dealing windows for personal solace. 

    Even before the pandemic, wild bird products comprised a $20 billion a year sector of the entangled Canadian and US economies. Since COVID’s arrival, sales of birdseed, birdhouses and feeders have leaped. Add the spending of bird watchers and their activities and one study estimates it exceeds $80 billion a year. 

    There are 57.2 million birdwatchers in the US and another 7.5 million in Canada. Recreational surveys by various government and marketing agencies report that we now spend more time at birding than most other recreational activities.

    Canadians, for example, spent an average of 133 days a year watching, monitoring, feeding, filming or photographing birds compared to an average of 70 days we spent gardening.  

     

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    Bird-watching is more popular than golf these days

     

    When you start to crunch the numbers, it becomes a mystery why so many municipal governments and developers invest so much effort obsessing over golf courses when the real public need on the basis of interest alone, is for bird sanctuaries and for more undomesticated parkland that provides habitat for the birds that people are so eager to watch.

    Think about it. There are about 64 million birders in Canada and the US. That’s almost three times the number of golfers (24 million) in both countries. It’s almost three times the number of the total attendance for every National Hockey League team. It’s three times the total attendance of the National Basketball Association and almost four times the total attendance of the National Football League. And 17 million more people watch birds each year than attend theatrical performances in both countries.

    Bird watchers spend big money on their pastime. One economic study of birders in the US, before the pandemic, reported they spent $15 billion just travelling to birdwatching sites and spent another $26 billion on equipment.

    The 57,000 birdwatchers who visit the famous sanctuary at Point Pelee, Ontario, spend an average of $549—just to watch the migratory birds that will later perish crashing into the towers of Toronto flying north, and Detroit flying south. 

     

    Out of sight, out of mind

    In the face of our appreciation of the aesthetic, spiritual and economic value of birds, one wonders why we don’t put a great deal more effort into rendering the urban landscapes that attract them less lethal.

    As far as I can determine, no diligent data-obsessive researcher has yet actually counted the number of glass windows or how many hectares of glass wall are created by our architectural fetish for cladding commercial high rise towers, up-market condominiums and apartment blocks in transparent and reflective materials.

    As noted above, the amount of glass in a building is the strongest predictor of how dangerous it is to birds. So not knowing how much glass there actually is remains a curious absence. 

    About 56 percent of bird fatalities from collisions involve commercial glass—lower buildings are far more dangerous than skyscrapers simply because most birds do most of their flying close to the ground. The other 44 percent die colliding with residential glass. 

    A simple, anecdotal check with window cleaners online suggests that the average home of 192 square metres has about 25 windows, (although about 25 percent of British Columbians live in larger houses with considerably more glass). Calculated another way, construction guidelines generally aim for a window or glass door in every room on the building’s external perimeter. The glass should be equal to at least 10 percent of the floor area of the room at a minimum. Most of us prefer more natural daylight and therefore more glass. 

    In the Capital Region, according to census data, there were 172,559 private dwellings reported in 2016. A simple extrapolation from that—acknowledging that this is a conservative guesstimate because it doesn’t account for cladding and windows on commercial office, institutional and residential towers—projects at least 4.4 million windows across the near 700 square kilometres of Greater Victoria.

    Every one of those windows is a potential death trap for flying birds. Few are the householders who haven’t heard the thump of a bird colliding with a window, patio or other door. Sometimes we are left with the sad disposal of a dead bird, often we just hear the noise and never find the feathered corpse. We like to reassure ourselves that the bird survived the collision and flew away, but researchers at the American Bird Conservancy say that’s unlikely.

     

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    A too common occurrence near buildings, though often hidden in the bushes

     

    “Birds suffer internal hemorrhages, concussions  or damage to their bills, wings eyes or skulls,” they observe. “While they may be able to fly away temporarily, birds with even moderate injuries are much more vulnerable to predators and other environmental dangers.”

    The reason we aren’t presented with a constant litter of dead and dying birds, the researchers point out, is because they usually strike the glass at high speed, bounce off and land some distance away, often obscured by plants or other objects. And scavengers like rats, raccoons, crows and house cats will quickly carry off dead and injured birds.

    In fact, the scientists say, smart scavengers may actually check several times a day at a window where there are frequent bird strikes. 

    Out of sight, out of mind, so we remain largely oblivious to the magnitude of the carnage, which Oklahoma State University researcher Scott Loss has characterized as “death by a million nicks.”  

    All of which gives me pause whenever I read of striking architectural plans which feature more vast walls of glass surrounded by both external vegetation at the perimeter, rooftop gardens designed to attract pollinating insects and plants inside glass atriums.

    What’s the environmental ethic of designing structures that are aesthetically appealing to humans but may be lethal to the birds they attract? 

     

    What to do?

    This isn’t to scapegoat architects or developers or householders, city planners or municipal politicians, it’s just to say we all need to start thinking differently about how we modify our urban environments. 

    There are indeed ways to substantially reduce bird kill from window collisions but they demand that we rethink the balance between our aesthetic demands and the impact of those demands upon avian wildlife.

    Windows with clear glass are invisible to birds while reflective glass creates illusions of vegetation and sky into which birds will seek to fly at high speed. Changing the type and use of glass, angling windows to reduce reflection, minimizing the appearance of space as a pass-through, all work in different degrees and applications. So collaboratively designing buildings to mitigate risk should, in my opinion at any rate, be at or near the top of the agenda when municipal governments discuss development proposals.

    At the University of British Columbia, where an estimated 10,000 birds a year crash into windows and glass panels—a campus survey of just 45 buildings tabulated collisions averaging from 45 to 72 a day—researchers developed a strategy for mitigating bird fatalities.

    Among the solutions: increasing the visibility of new glass by acid-etching it with patterns; using ultraviolet patterned glass which birds can see; retrofitting existing glass with transparent film that’s invisible to us but visible to birds. Some are temporary and inexpensive, some permanent.

     

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    UBC bookstores bird-friendly windows

     

    At UBC’s bookstore, for example, a large expanse of external windows is etched with the sentences from the favourite books of professors. The windows still allow light into the building and patrons can see out, but the dense pattern of text creates both an artistic feature appropriate to the building and a wall of visual noise that provide highly visible cues to approaching birds.

    The university’s forward-thinking Green Action Building Plan, adopted by the board of governors in 2018, incorporates a requirement for all new structures on the campus to have 100 percent compliance with bird-friendly design elements by 2025.  

    Some of the fixes are low tech and low cost. Researchers at UBC and elsewhere report that, reducing vegetation near windows seems to reduce bird collisions with glass. So does certain structural angling of windows to reduce reflections that create an illusion of three-dimensional space. Both high-rise and low-rise buildings reduce bird collisions when they reduce or eliminate light emission at night from interior illumination.

    Meanwhile, there remains a great deal we still don’t know about the phenomenon: 

    Interior illumination is associated with birds that migrate at night flying into the glass of commercial buildings at fatally high speeds—but is this also true for the many more residential buildings? There’s little data. 

    Residential buildings outnumber skyscrapers—perhaps by a factor of almost 6,000 to one—so rethinking suburbia is as important a challenge as trying to reduce bird kill in downtown cores. And rural residences may be even more of a threat than suburban ones simply because they intrude more into bird habitats.

    Faced with choices between increased vertical density and broader urban sprawl, it seems clear that local municipal planners who talk a great deal about sustainability and biodiversity should, like their colleagues in other major Canadian cities, be engaging the public in a far broader, more vigorous conversation about what it means for the birds that surround us and bring so much pleasure and value into our lives.

    For more information see flap.org and UBC’s bird-friendly design guide.

    Stephen Hume has spent half a century as a journalist writing about Western Canada, the Far North, BC and the Island. 

     


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