Last summer NestWatcher Melissa Sherwood surprised us with the first ever report of a Dark-eyed Junco nesting in an enclosed nest box. Juncos are typically open-cup nesting birds that build nests on the ground. Well, we had another surprise this summer! Cornell Lab member Denise Hamilton of Napa Valley, California, discovered our second report of a junco in a nest box! Notice that this nest is much larger, filling the space of the nest box. Below, Denise relays the details:
My husband, David, and I have become known as “the birders” at our church, so it isn’t surprising when someone asks us a bird question or shows us a picture of a bird to identify it. However, I was surprised this time when my friends Laura and Tom Schmiegel asked me on May 21, 2017, “What is this bird nesting in our box?” It was a dark, tiny picture on a phone, but I could clearly make out that it was a Dark-eyed Junco! I told them that juncos don’t nest in boxes and asked if we could come over to verify and take a picture or two. Of course, an hour or two later, the birds had fledged and we missed them!
We started looking online and only came up with one confirmed nesting in a box—that of the NestWatch project in April 2016. I quickly got in contact with biologist Robyn Bailey of NestWatch, and we emailed back and forth about whether or not it was really juncos nesting in the box. Luckily our friends were willing to give me their box so I could remove the nest. Getting the nest out of a decorative bird box wasn’t easy, but it proved that it was indeed a junco nest (sadly, it held an almost fully-feathered nestling that had died). I truly find it amazing that after finding no records of juncos nesting in boxes, that in the time span of two years, NestWatch now has two! I just wish it would have happened in my yard!
Denise raises the interesting question of whether we are witnessing a trend. It’s difficult to know if juncos have been nesting in old woodpecker holes and other cavities, unseen by humans, for thousands of years. But we do feel cautiously confident that nesting in birdhouses is a relatively new expression of this behavior. One lucky NestWatcher named John Barber witnessed Dark-eyed Juncos nesting in an open-fronted nest box (2009), and then a different pair nesting on top of it (2016). John knows that it was not the same pair because the birds were individually marked with leg bands.
These three nest boxes have a few things in common: they are shallow and wide, and located in residential areas. Discoveries such as these raise the question, is there a “Dark-eyed Junco nest box” in our future?