Just after dawn in mid-May, Nick Lund and three volunteers gather in downtown Portland to start a different kind of birdwatch in the city.
Peering under windows, the team isn't looking for live birds, they're looking for dead ones.
Lund, an advocacy and outreach manager for Maine Audubon, said volunteers walk a two-mile loop daily during spring and fall migration to take an accounting of birds that have crashed into the glass windows of the city's buildings.
"Birds don't know what windows are, and they see the reflection of the sky or the reflection of habitat, which looks like safety to them, and they fly in and collide," Lund said.
The "BirdSafe Maine" monitoring effort started in 2020 in an attempt to quantify the toll Portland's buildings were taking on birds during the spring and fall migrations.
The American Bird Conservancy estimates building strikes kill more than one billion birds every year in the United States. Collisions with windows is a leading threat to birds, after feral cats and habitat loss, according to a recent state report.
The total number of bird deaths from building strikes in Maine is unknown. Data from the BirdSafe Maine program shows more than 1,000 dead or stunned birds — mostly migrating warblers and sparrows — have been recorded in Portland alone.
Lund said the true number is likely much higher, since volunteers only monitor certain buildings, some strikes go unrecorded, or Portland's resident gull population eat fallen birds before they can be counted.
"It's a sad problem to see when these birds are migrating from thousands of miles away, crossing oceans and coming all this way, to then die against a window," Lund said. "It just feels really wrong. Trying to reduce that number is what we're after."
There are, however, straightforward solutions that make buildings safer.
Lund pointed out an alley off Commercial Street, which used to be one of the worst kill zones for birds in the entire city.
Migrating birds arriving in Portland would rest in a stand of tall trees adjacent to the high glass windows of the MEMIC workers compensation insurance company. When birds took flight, some went headlong into the building.
"There were volunteers who had really difficult emotional days where birds were raining down on them from this really nondescript alley," Lund said.
Then two years ago, MEMIC installed bird-safe window decals on the windows seeing the most strikes. The film features small, closely clustered dots that break up the reflection and lets birds know they can't fly through.
Lund said the adjustment made a huge difference.
"We haven't found a single dead bird down here since they installed that stuff, which is amazing. Even more effective than we expected it to be," he said.
At the time, MEMIC spokesperson Lily Hanstein said installing the decals was a challenging decision, but ultimately the right choice.
"Our employees are passionate about animals and hearing a bird hit the window while you are working isn’t a great feeling," she added. "It’s been heartwarming to see the level of appreciation from the birding community and we are thrilled to see that it is making a difference for the bird population.”
Chris Maher, a biology professor at University of Southern Maine helped start the BirdSafe Maine group with Maine Audubon and the Portland Society for Architecture, and says bird-friendly preventative measure really work.
Maher said BirdSafe wanted to make sure it was collecting good data to make its case for better protections across the city.
According to the group's findings, just eight buildings in Portland accounted for nearly 70% of the documented strikes.
"Because we have been so systematic about it, we could see very clearly which were the most problematic buildings," Maher said.
Armed with that information, the group encouraged building owners to help prevent strikes.
Then in 2024, Portland's city council passed the first building regulations in New England aimed at protecting birds. Under the rules, most new buildings or additions of more than 10,000 feet have to include bird-safe features.
A year later, the Maine Department of Administrative and Financial Services released guidelines to implement bird-safe designs in new public buildings.
The Portland waterfront building that houses Wex, a payment processing company, was one of the city's most dangerous buildings for birds until the company installed film on some of its glass windows. L.L. Bean's new headquarters in Freeport was designed to be bird-safe and so was the Crewe Center for the Arts at the University of Southern Maine.
Maher said retrofitting existing glass can wind up being expensive, so it's cheaper in the long run to design buildings with birds in mind.
Maher said although big buildings with lots of glass get the most attention, collisions with people's home windows kills and injures more birds overall.
But even in those cases there are things people can do to make their homes or apartments safer, Maher said. Options include adding temporary decals, parachute cord, tempura paint or even big screens to the outside of windows.
Cities across the U.S. and Canada are adding new regulations to make buildings safer, Maher added.
"You just have to give the birds something to cue in on, because, and again, birds are very visual animals. It takes up a big chunk of their brain, so they have to be able to see where that something's there," Maher said.
In Portland, Lund and the volunteers didn't have any casualties to report on their morning tour. Regardless, bird-building collisions are a major problem, Lund said.
And protecting birds from collisions is even more important now as species experience steep population declines. The Cornell Lab of Ornithology estimates that 3 billion breeding adult birds were lost across North America in the last 50 years, about a quarter of the total population.
Portland might be a small piece of that national puzzle, but it's an important one, Lund said.
"We are seeing the benefits in the city of Portland, for sure," Lund added.
"I mean, we saved hundreds of birds just at the buildings that we've treated and at new buildings going up, but the more that we can get architects to utilize bird-safe glass and become familiar with the techniques and the products, the more birds we're going to save around the country."
