Published: 06/14/2022

Just before dusk on 6 June at Hilton Pond Center we were preparing to close down banding operations for the night when we watched two white-gorgetted Ruby-throated Hummingbirds (RTHU) enter a passive Dawkins-style trap baited with a sugar water feeder. (This cylindrical plastic mesh device is amazingly effective as hummers fly in through an open door but forget how to get back out.) We knew the two weren't adult males--which would have red gorgets--and surmised both were adult females.

 When we reached in to secure the first bird we could tell from feather condition and configuration she was indeed an adult, but the second bird truly surprised us. Although she, too, was a female, her bright yellow gape told us she was a recently fledged youngster--what we call a "hummerling." 

So why was this particular hummerling such a surprise? Well, in 39 years of banding ruby-throats at Hilton Pond, 6 June is the THIRD EARLIEST date for a young Ruby-throated Hummingbird--and not by much. Our earliest fledgling male was on 4 June 2005, and our earliest female fledgling on 5 June 2008.

 In a typical year, we don't even start seeing good numbers of immature hummers-of-the-year until late June; in fact, since 1984 we've caught just 49 RTHU fledglings before 1 July--a little less than 1% of all 6,005 hatch-year ruby-throats banded. If more youngsters appear in the next week or so it may mean the species has gotten off to a particularly good start in 2022. (Perhaps weather conditions in late April this year were conducive to survival of eggs and hatchlings.)

Incidentally, with hummers already fledging in early June it's a good thing those Trumpet Creeper vines around the Center have started to bloom, providing a rich nectar source for free-flying youngsters.

But now we have a problem: No longer this spring can we look out the window of our old farmhouse and assume every white-throated hummingbird is female. Some will be, of course, but from now on many RTHU at Hilton Pond Center could be female-mimicking white-throated young males that have not yet started to acquire those tell-tale red gorget feathers sported by adult male Ruby-throated Hummingbirds.

 —Dr. Bill Hilton Jr., executive director, Hilton Pond Center for Piedmont Natural History

Original post: AUSPCIOUS HAPPENINGS: #76,000 . . . AND A HUMMERLING