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NestWatchers Document Rare Use Of Nest Boxes By House Finches

Photo © Ethan Heinold

by Robyn Bailey, NestWatch Project Leader

House Finches are one of the most common birds found nesting on and around human habitations from southern Canada extending all the way to southern Mexico. Their abundance and adaptability when nesting near people has made them one of the best-studied birds in North America, and yet they are still capable of surprising us.

People have been placing nest structures to attract House Finches since at least 1908 (Bergtold 1913), so they have nested alongside us for more than a century. Because the House Finch was originally native to western North America, its colonization of the east from the 1940s through the 1980s (by both introduction and natural range expansion) caused some easterners concern that they would compete for nest boxes and natural cavities (Jackson et al. 1986).

An Unexpected Family

An Unexpected Family

In 2022, House Finches raised two successful broods of five inside one of Lee's bluebird boxes. The entrance hole diameter of this box is 1 1/2".

So far, this dire prediction has not come to pass. In fact, when House Finches nest in an enclosed nest box, it is rare enough to stand out—only a few NestWatchers have reported this. It is similarly rare among those who recorded for the Cornell Lab of Ornithology’s historical North American Nest Record Card Program. The House Finch is not an obligate cavity-nester like woodpeckers, Purple Martins, and Wood Ducks. They can choose to make a cup nest in vegetation or on human-made buildings, or even in the old nests of other birds. Because they do not require a cavity, their occurrence in nest boxes is a novelty rather than the norm.

Lee’s California Finches

In 2014 and 2015, Lee Pauser witnessed House Finches making a total of 12 nests inside American Kestrel and Barn Owl nest boxes on his California trails. Lee monitors hundreds of nest boxes every summer, but this struck him as unusual. Because these boxes are for larger-bodied birds and the nests were near the entrance, Lee hypothesized that the finches must like a lot of light.

A Spacious Choice

A Spacious Choice

In 2014, House Finches made a nest inside one of Lee Pauser's Barn Owl nest boxes. They did so again the next year, and also tried out one of his American Kestrel nest boxes as well.

That theory came into question on April 12, 2022 when he found his very first House Finch nest inside a bluebird box. This nest contained five eggs which eventually hatched and fledged. A second brood was attempted, and it was also successful. For those counting, this brings Lee’s total to 14 nests inside nest boxes. This surely is a localized breeding behavior, perhaps something that his local finches have learned from one another? Given the many thousands of NestWatchers monitoring bluebird boxes, if finches were using them with any regularity, this would show up in the data; however, it remains a rarely-reported event.

Igniting A Passion

Igniting A Passion

Ethan's observations started in 2018, when a House Finch used this traditional songbird nest box mounted under his home's eaves. Monitoring their nests helped ignite his passion for assisting these birds.

Meanwhile In Colorado

In 2018, NestWatcher Ethan Heinold noticed a House Finch using a traditional nest box mounted under the eaves of his home. This nest was successful, and the box even sheltered the finch family through a late spring snowstorm that year. Ethan found it curious that they chose to use the fully enclosed nest box, despite there being a more open nest shelf nearby.

Ethan’s interest in the little birds was piqued years ago when he noticed House Finches inspecting porches, gutters, and eaves around the neighborhood for suitable nesting sites. As he put it, “Once I noticed this, I wondered if I could build them a place to nest. My first design attracted a pair, and they built a nest so I kept experimenting.” His original designs were more open, and were attractive to the finches; however, the local Woodhouse’s Scrub-Jays were clever enough to figure out their purpose and raid the boxes. After trying three other styles, he has recently settled on a style he calls the “eavebox,” which resembles a nest box with a triangular opening mounted face down. The bottom-facing entrance has been effective at stopping scrub-jays from entering, and allows the finches a quiet crevice in which to nest.

Underneath The Eaves

Underneath The Eaves

This custom-made nest box was built by Ethan after he noticed predators finding the House Finch nests in his former boxes. With its bottom entrance, this one is resistant to curious jays.

How lucky are Ethan’s local finches to have their own personal builder who iteratively creates ever-improving nest boxes for them? Perhaps other NestWatchers will want to follow suit and experiment with this fairly simple design mounted on their own homes. Ethan notes that there are not many House Sparrows in his neighborhood, so he has not yet witnessed any competition for the eavebox. If you decide to use a nest structure like this, we welcome you to tell us about your experience!

Flexible Finches

Other NestWatchers have documented House Finches using nest shelves and shallow cavities intentionally provided for birds (see gallery below). The House Finch’s flexibility in nest site choice means that it hasn’t become a serious competitor for nest boxes in North America.

  • A House Finch nest sits on a wooden nest shelf
    Photo by Margaret Vitalis

Because at least some House Finches use nest boxes, caution is warranted among those who manage against invasive species. The female House Finch and her young are occasionally confused with House Sparrows, a non-native species in North America that many nest box stewards manage against. They can be told apart by differences in egg coloration and pattern, as well as nest shape. Males of these species are also very distinct from each other, as is their song. Because the House Finch is protected under the Migratory Bird Treaty Act, people who manage House Sparrows in boxes should take care to review these differences in the downloadable image provided below.

Is It A House Finch Or A House Sparrow?

Is It A House Finch Or A House Sparrow?

Click image to enlarge.

Have House Finches nested in your nest boxes, or do they stick to ledges, eaves, and vegetation? Regardless of the substrate, consider reporting the nesting data to NestWatch. Learn more about how to enter data in our FAQs.


References:

  • Bergtold, W.H. 1913. A study of the House Finch. The Auk 30(1):40–73.
  • Jackson, J.A., B.J. Schardien Jackson, and M.F. Hodges, Jr. 1986. First breeding of the House Finch in Mississippi. The Mississippi Kite 16(1):10–12.

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4 responses to “NestWatchers Document Rare Use Of Nest Boxes By House Finches”

  1. Mary Wood says:

    Hi,
    I live on Cape Cod and have a Lot of House Finches, which I Adore.
    I have two blue bird boxes up, and have been lucky enough to attract them.
    The blue jays keep wiping out the bluebird nestlings.
    I had a pair of Carolina wrens successfully raise three chicks in my garage; as we leave the door open for them. It saves them from the jays.
    If I attach a bluebird box to the house, will the Finches perhaps nest in it?
    What else can I do to protect the Bluebirds.? Best

  2. James Hill says:

    I wrote a paper on this in 1988: Hill, J. R. 1988. The eastern House Finch nesting in Purple Martin houses and gourds. American Birds 42:36-38.

    A pair successfully nested in a 24-compartment, aluminum Purple Martin House in Pennsylvania.

    • Robyn Bailey says:

      Hi James,
      Thanks for sharing this reference! I didn’t find this one in my search, probably because I wasn’t thinking about gourds or Purple Martin housing, and used key words like ‘nest box’ and ‘birdhouse.’ That is an interesting paper, and I wish I had seen it sooner. I can tell you that in my search of our photo records and comments about nest sites, none appeared to be in Purple Martin housing.
      All the best, Robyn Bailey

  3. Chrisula Stone says:

    What an interesting phenomenon! It must have been a real surprise to find finches in the owl and kestrel boxes!

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Cornell Lab of Ornithology

Cornell Lab of Ornithology