For the Birds: Bluebirds, windows and houses

Photo by Chris Bosak An eastern bluebird gets a drink from a birdbath in New England, February 2020.

I’ve been getting quite a few emails about bluebirds lately. I see that as a good sign about the rebounding eastern bluebird population.

Cornell Lab of Ornithology’s, my go-to website for information about North American birds, says the eastern bluebird is a species of “low concern.” The site reads, “Eastern Bluebird populations fell in the early twentieth century as aggressive introduced species such as European Starlings and House Sparrows made available nest holes increasingly difficult for bluebirds to hold on to. In the 1960s and 1970s, establishment of bluebird trails and other nest-box campaigns alleviated much of this competition, especially after people began using nest boxes designed to keep out the larger European Starling. Eastern Bluebird numbers have been recovering since.”

Jim and Eleanore of Keene wrote to say that they have nesting bluebirds for the first time in the 50 years they have been at their home.

“They are nesting in a house in my flower/vegetable garden,” Eleanore wrote. “From day one Mr. bluebird has been pecking on our kitchen window, all day long!”

I received a similar email from another reader relaying that a bluebird was doing the same thing at their house.

Like most birds that peck on windows and mirrors, they are likely trying to chase the “other” bird away. Birds are territorial during nesting season and will not tolerate other birds of the same species poking around. Robins and cardinals are also notorious window attackers.

To prevent this from happening (perhaps anyway), try placing stickers on the outside of the window to break up the reflection. You can also try to dangle something in front of the window or put a planted flower on the outside windowsill. Anything to break up the reflection. This, of course, is also effective in preventing bird strikes.

Last year, Jim and Eleanore sent me a charming story about a baby robin that they cared for last summer until the mother bird was able to take over. The story is a fun read and is now on my website,, if you care to check it out.

Another question came in from Renee who inquired about how far bluebird boxes should be from each other. She also has tree swallows competing for the houses and wondered if that impacted the distance.

I checked out information from the North American Bluebird Society and it suggested that eastern bluebird houses should be at least 100 yards apart. That’s an entire football field (minus the end zones) so quite a bit of space is needed to attract more than one bluebird pair. However, the distance shrinks substantially when tree swallows are around and the goal is to have a bluebird pair and tree swallows pairs together.

“When paired, boxes should be mounted 5 to 15 feet apart. This provides nesting sites for both species and helps to prevent competition between them. Different species of native birds usually do not mind nesting close to each other,” the NABS site reads.

I am hopeful that the abundance of emails about bluebirds means that the species is doing so well that more and more people are seeing them because there are that many more bluebirds around. I know I hosted my first bluebirds at my backyard feeder a few years ago. What a thrill that was to see them daily in the backyard.

I hope more people feel that joy in the years to come.

1 thought on “For the Birds: Bluebirds, windows and houses

  1. An exciting read. The number of bluebirds in our neighborhood has been increasing noticeably over the last few years. Currently, two of our five birdhouses have bluebirds in various nesting phases. At one house they are about to fledge at the other the female is still sitting on the eggs. Our biggest challenge has been protecting them from rat snakes and aggressive English sparrows.

    Liked by 1 person

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