by Robyn Bailey, NestWatch Project Leader
As frigid temperatures grip the northern states and a nor’easter threatens the east coast, most of us are probably not out checking nest boxes. However, participants in the southern states know that it’s just about the start of the nesting season. From my snow-covered office in upstate New York, I was astonished to see that two NestWatchers have already reported an Eastern Bluebird nest with eggs as of January 27, 2022.
One of the clutches was initiated some time between January 18–21 in a northeastern Florida retirement community. According to Faith Jones, the Florida Bluebird Society board member who submitted this nest, “These are the earliest eggs in our records.” Faith explained via email that, “We started monitoring in January as we know there was an active nest in Panama City, Florida, in late January 2019. This is the first year we are trying to report with the NestWatch app as we monitor, and [we] are using an endoscopic camera so we do not have to open all the boxes to view activity.”
Another early nest was reported from Texas with a first egg date of January 22. NestWatcher Larry Streib reports this nest box also hosted an Eastern Bluebird’s nest in January of 2021, but that one failed due to the record-setting winter storm that slammed Texas that winter. Could it be the same female, trying her luck again as an early bird?
January nests are remarkable because Eastern Bluebirds are one of the most popular species reported to NestWatch, and yet nests with first egg dates in January make up about 0.01–0.02% of all Eastern Bluebird nests with known first egg dates (this range represents some uncertainty around nests which were difficult to verify).
But why would bluebirds, or other year-round songbird species, nest so early when the chances of succeeding are small? Faith hinted at an answer: “We had warm weather in early January, but it has turned cold (by Florida standards).” Birds do use temperature, but also day length, as a cue for when to start breeding. Recall that after the winter solstice (the shortest day of the year)—December 21 in the Northern Hemisphere—the days start gradually getting longer. This subtle increase in the amount of daylight is enough to trigger some birds to respond hormonally. Coupled with unseasonably warm temperatures, we might see some birds behaving as if spring were already here. But for most of us, if we see birds entering our nest boxes this time of year, it is more likely they are roosting in there to conserve heat. Statistically it is very unlikely that they’d be nesting this month. But some January nests do succeed, and we’re keeping our fingers crossed for Faith and Larry that their bluebirds’ risk pays off.