For the Birds

As Alameda embarks on a construction boom, the city is exploring ways to protect birds from flying into glass buildings.


Up to a billion birds die each year nationwide from flying into buildings.

Photos by Dave Strauss

Ever heard the sickening thud of a bird flying into a window? If so, you are far from alone. According to a 2014 study by the Smithsonian Conservation Biology Institute and the U.S. Fish and Wildlife Service, building collisions may kill up to one billion birds nationwide each year.

The problem is that birds see the world differently from humans and are not adapted to know what glass is. Trees and sky reflected in panes of glass appear to birds to be habitat, as do trees and sky that are visible through glass windows on the other side of a building. Even a bird’s reflection can lead to a strike, especially in the case of male hummingbirds, which chase territorial challengers at breakneck speed.

But now the Alameda City Council is taking steps to address this avian tragedy: In April, the council voted to ask city staffers to provide standards for bird-safe buildings for the council to consider at a future meeting.

Only a handful of diehard birders were in the room when the council finally got to vote, in the wee hours of April 19 on the bird-safe buildings directive, but billions of birds that live here year-round, or follow the Pacific Flyway annually as part of their migration, stand to benefit from the council’s decision. It aims to establish bird-safe planning standards for new building construction and replacement facades. And bird advocates praised the move, which they deemed urgent given the thousands of housing units that are teed up to be developed, as part of Alameda’s planning pipeline.


A dazed brown creeper recovers from running into a window.

“It’s important to get ahead of the development cycle,” said Golden Gate Audubon Society Executive Director Cindy Margulis, in an interview. A year ago, her group started a program to train architects to use bird-safe techniques for buildings, she said. “What we found was that the architects told us, ‘Hey, this is really cheap to do; this is not an expensive fix,’” she said. “So it’s just something they need to know very early in the planning stage so they can factor it in. They were like, ‘This is cool because I would rather have my building not kill things!’”

Margulis noted that bird-safe measures often have environmental and economic benefits: For instance, the use of fritting—ceramic patterns on glass that birds can see but that don’t prevent people from looking through windows—reduces heat gain and decreases cooling costs, while deterring bird strikes. In recent years, Golden Gate Audubon Society worked with officials in San Francisco, Oakland, and Richmond to pass legislation that included bird-safe building standards, tree-care schedules, and bird-friendly light positioning.

But now the group has developed an even greater understanding of what triggers bird strikes, thanks to a new report based on five years of strike data from the California Academy of Sciences’ new three-story building in San Francisco. The need for the report, which is one of the first to focus on flyways on the West Coast, was triggered in spring 2008, when museum staffers moved into CAS’ new building in Golden Gate Park and began noticing that the building’s glass exterior posed a major, and often fatal, collision threat for birds.

The resulting report, which was published in 2016, found that “actively migrating birds may not be major contributors to collisions,” and that “male and young birds were significantly overrepresented [in bird-strike casualties] relative to their abundance in the habitat.”

The good news is that these bird deaths can often be prevented with simple, cost-effective mitigation measures. These include replacing large panes of glass with smaller panes, installing retractable shades on the outside of windows, and using fritted glass.

But it’s not just windows that kill birds. Lighting can get in the way of a bird’s ability to navigate by the stars during migration. Lighted buildings and towers can draw birds off course and result in exhaustion, injury, or death. The excessive use of interior and exterior lighting interferes with birds’ sleeping patterns.

Margulis notes that Alameda is a really important place to pass bird safety legislation. “There is such important birdlife in the city,” she said, noting the presence of a colony of endangered least terns at Alameda Point, the Elsie Roemer Bird Sanctuary at Shore Line Drive and Broadway Street, and the San Francisco Bay, which is an important migratory corridor for species from around the world. “Basically, you have Alameda sitting in the middle of the bay,” she said.

So could Alameda’s actions start a national trend? Alameda resident Patricia Gannon, who showed up at City Hall in April to urge the council to support a bird-safe ordinance, certainly hopes so. As Gannon stated recently, in an email to the council, passing bird-safe building legislation “could encourage neighboring cities to do likewise.”


Published online on June 7, 2017 at 8:00 a.m.