We have had Eastern Bluebirds nesting in a nest box in our front yard in Concord for several years now. In 2025, I came back from vacation in early July and discovered that Northern House Wrens had built a stick-nest on top of the pine needle-bluebird nest. The bluebirds had already had at least one brood fledge. I watched for a few days as the bluebirds tried to reclaim their nest and kick out the female wren who appeared to be sitting on eggs. The wrens stayed put with the male wren protecting his new territory. Eventually, the bluebirds gave up. Our house also has several House Finch nests on it, and I noticed the bluebirds hanging around a finch nest but didn’t give it too much thought since I know they are cavity nesters.   

On August 2, my son Jacob observed a bluebird sitting on the House Finch nest which is on top of a second floor AC unit, so I decided more careful observation was in order. The next morning, I sat out for an hour to watch the nest. I saw the female bluebird sitting on the nest, bringing food, and removing a fecal sac. I also saw the male bring food. I couldn’t see the babies since it is so high up, but it appears that the bluebirds did indeed take over an open House Finch nest.  

The male bluebird bringing food to the nest. Photo by Alison Rhodes.

Alison Rhodes took this photo on 8-2-2025, confirming an Eastern Bluebird using an open-cup nest in Concord, NH.

Editor’s Note: Eastern Bluebirds are famous for nesting in tree cavities and nest boxes. According to Birds of the World, Eastern Bluebirds use open-cup nesting sites only on rare occasions. This is most likely to occur in longleaf pine trees, an endangered southeastern tree. There was also a reference to an occurrence in Bermuda in the late 1800s when bluebirds were “unusually abundant,” so they “forsook” cavity nests and began to use open-cup nests. 

Reference

Gowaty, P. and J. Plissner. 2020. Eastern Bluebird (Sialia sialis), version 1.0. In Birds of the World (A. F. Poole, ed.). Cornell Lab of Ornithology, Ithaca, NY. 

Enjoy this field note? Check out other field notes from Fall 2025!

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Want even more? Visit our “From the Field” page.