A laminate of dots has been applied to many of the windows at the newly constructed L.L. Bean headquarters in Freeport. The dots help minimize bird collisions into the windows. Gregory Rec/Staff Photographer

Andrea Imperato felt lucky to be renting a North Berwick home that’s situated beside 60 acres of open hayfields with abundant wildlife. Then the danger to bird life became apparent.

The expansive view led birds to the windows, where bluebirds pecked or scratched at the reflection. In June, Imperato found a dead Eastern bluebird lying on the ground beside a window. She called the Center for Wildlife and was directed to Maine Audubon’s BirdSafe team, where she learned how frequently birds die from window strikes. The experience, she said, was horrific.

“At the door that leads out to the yard, there is a big glass panel,” Imperato said. “What I noticed last year was the bluebirds in particular would come up to the window and see their reflection and scratch at it. I’d see a little bird pecking at himself. There would be all tiny blood marks. It was a little guy trying to protect his brood. The one that dropped was at one of the front windows. It must have bumped itself and dropped.”

Bird strikes on windows cause an estimated 365 million avian fatalities a year, making it a leading cause of bird mortality, according to the U.S. Fish and Wildlife Service. The reflection of skies or trees on the windows is the primary cause of bird strikes. Maine Audubon has been tracking bird strikes against windows the past several years, and has asked the public to email photos of bird strikes to birdstrike@Maineaudubon.org.

Only a handful of buildings in Maine feature bird-safe glass, but advocates are hopeful that each new example of such buildings will help spread awareness. Most recently, L.L. Bean and two colleges made the choice to make windows safer for birds.

This summer, L.L. Bean added an outside window treatment from Canadian-based Feather Friendly that put sheets of dots on the outside of the windows, a method that helps break up the reflection. Even simple window screens can do the job of alerting birds to the barrier. But the glass used in most buildings reflects the horizon, causing birds to mistake windows without screens for a flyway in the distance.


Construction on L.L. Bean’s new headquarters started in 2019, and the company considered adding bird-safe technology from the start, said Jason Sulham, L.L. Bean’s manager of public affairs. This summer, the adhesive strips with dots were added at a cost of just over $60,000, Sulham said.

Cole Hutchison raises a lift to apply a laminate of dots on the windows of the new L.L. Bean headquarters in Freeport on Aug. 5. The dots help minimize bird collisions into the windows. Gregory Rec/Staff Photographer

“With insight from Maine Audubon, the American Bird Conservancy, and Portland Society for Architecture, we selected a post-construction dot or frit application that was based on effectiveness,” Sulham said. “We recognized that witnessing bird strikes would be an unpleasant and even traumatic experience for employees, especially at a workplace that values wildlife conservation. The health and wellbeing of our employees was therefore a significant factor in our desire to utilize bird safe technology.”

Saddleback ski area in Rangeley is building a mid-mountain lodge with a bird-friendly design. The low-lying building will serve as a rest stop with a restaurant halfway down the mountain. Window screens that can be removed in winter – when birds are not migrating – were incorporated into the design. 

At the College of the Atlantic in Bar Harbor, the $10-million, 30,000-squarefoot Davis Center for Human Ecology was built last year with a triple-pane glass from Germany that is nearly imperceptible to humans but obvious to birds. The specialty glass added an additional $97,000, said Darron Collins, the college’s president.

Collins said cost savings were needed to stay on budget, but the college eliminated a stairwell and other features instead of giving up the bird-safe glass. A campus-wide plan created seven years ago mandates all new buildings on campus use the specialty glass.

“I’ve given more than a 100 individual tours in the building. It is one of the most exciting things they talk about,” Collins said. “The whole idea is borrowed from the orb-weaving spider. They use UV-reflective silk in their web so that birds don’t fly through the construction. It’s a great example of biomimicry in construction. It just amazes people.”


Five years ago, the University of New England introduced one of the first buildings in Maine with bird-safe glass when the design of the university’s new 60,000-square-foot student center was changed to add the protective glass at an additional cost of $200,000. 

Residential buildings with bird-safe glass seem to be rare, according to the Portland Society of Architecture, given that the cost can be as much as 18 to 20 percent more according to experts.  

“I would say it’s not common, but mostly because folks don’t know enough; assume options are too expensive; and assume the applications may mar the aesthetics. Homeowners definitely apply decals,” said Addy Smith-Reiman, the society’s executive director.

The decals are offered online by companies such as Window Alert and Bird’s Eye View. To cover a single window costs about $8 to $12.

Maine Audubon, in collaboration with the Portland Society for Architecture and the University of Southern Maine, launched the BirdSafe Maine program to inspire more bird-safe buildings. In the past two years, Maine Audubon has conducted a study in Portland’s Old Port during the spring and fall migration to determine how many bird strikes occur in the city, which is along a major migratory route. 

Maine Audubon had campers decorate this window and door glass at one of the buildings at its Gilsland Farm sanctuary in Falmouth. The artwork helps to minimize bird collisions into the glass. Gregory Rec/Staff Photographer

The data shows there were more dead birds in the early morning around buildings with a higher percentage of glass, said Nick Lund, Maine Audubon’s director of the BirdSafe program.


Based on the study’s data, Lund estimated roughly 40,000 birds collide with windows in Portland each year.

“This is part of a large, growing understanding of bird strikes around the country,” Lund said. “What we found in Portland matches what we expected. But it has taken longer for the issue to work its way up to the building and design process. It is not an issue taught in architectural schools. This is an emerging issue.”

To encourage more bird-safe buildings, Maine Audubon has started adding different kinds of bird-safe windows or window treatments at its Gilsland Farm headquarters to provide a place where people can come see the options. The nonprofit showcases the use of Feather Friendly dotted stickers, two other kinds of ultraviolet strips on windows, and even paintings on windows done by summer campers.

“When Gilsland Farm was built in the 1970s, (minimizing bird strikes on windows) wasn’t a widely accepted problem. The headquarters was a cutting-edge green technology. But this was not on the list,” Lund said.

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