A Tale of Two Hummingbirds?
By Nate • March 6, 2012 • 10 commentsOver-wintering hummingbirds have been a staple of birding in the southeast United States for the last 30 years or so, and in my state of North Carolina, it seems that a dozen or so are reported over the course of nearly every winter. At first glance, the idea of hummingbirds in the winter seems to be an odd one. There are few birds in North America so obviously tropical, so necessarily tied to flowers and sunshine and balmy summer afternoons on the back porch with some sort of gin-based mixed drink, but these winter residents are generally not our breeding birds, the dainty Ruby-throated Hummingbirds. These birds are the bulky Selasphorus, nearly all Rufous Hummingbirds. Feisty, tough as nails, and apparently of the opinion that even the worst Carolina winter is nothing compared to those summers in Rocky Mountain meadows.
This has been a particularly good year for over-wintering hummingbirds in the state, and my little town of Chapel Hill (Go Heels!) has hosted not one, but two Rufous Hummingbirds this winter at two sites not more than half a mile apart. Despite the fact that the two birds look nothing alike, this has obviously led to speculation that the birds in question may, in fact, be the exact same individual who, over the course of two months, is all grows up.
Is that a reasonable hypothesis? I’m no expert on Rufous Hummingbird molt, but the original bird, one of those subadults that invites confusion with the ridiculously similar Allen’s Hummingbird, was rough looking. And according to St. Pyle (patron saint of bird banders), Rufies go through a complete molt between their hatch year and second year, a time that corresponds to the period where the birds in question were in Chapel Hill*.
*if I’m wrong someone please set me straight.
So is it possible that our bird went from this…
November 2011
…to this?
February 2012
This little red stunner was discovered at the Coker Arboretum on the campus of the University of North Carolina. Remarkably, and bizarre for a vagrant hummer, it was attending a huge stand of exotic, ornamental, honeysuckles rather than a feeder, lending an air of legitimacy that the feeder-bound hummers sometimes lack. It just feels wild, and at the very least, I didn’t have to make that awkward call to the homeowner for permission to stake it out.
This second bird, present since the end of February, was a no-doubter Rufous, but still a young bird without the iridescent gorget. It shows little concern for those coming to see it, the benefit of camping out in a high traffic area on a college campus, and with a little time offers some really amazing looks.
Here’s the kicker though. The first bird was banded at the feeder, so this second bird, if it is, in fact, the first bird (still follow?) should have a tiny metal band around one of those tiny little legs. And unfortunately, despite the remarkably fine show this individual has been putting on, no photos have surfaced that can conclusively show that the birds are the same.
I’m certainly willing to entertain the possibility, but for my money, and having seen both of them, I see no reason to think we aren’t so lucky here in Carolina to have enjoyed two separate and unequal Rufous Hummingbirds this winter.
I toss the question to the hummingbird experts out there. Is this plumage transition a legitimate one?
Tags: hummingbirds, rufous hummingbird
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Nice pictures and a story, I have pictures of an albino humming bird, I will gladly share them with you, just not sure how to attach to here or Twitter
Could it be that the prevalence of feeders has encouraged some hummingbirds to change their winter quarters? Over here in the UK we now have a regular winter population of Blackcaps which originate from Germany and come here instead of going south for the winter (which our summer resident breeding Blackcaps still do)
I think you’re missing the bigger question here, Nate: How did you get such gorgeous photos?
Those are such great photos and at such similar angles, you could imagine doing some basic morphometrics. Using Photoshop, I find that the Feb bird’s bill is 7.3 times eye width, while the Nov bird’s bill is only 6.15 times. There are also subtle differences in bill curvature and depth at the base, and eye position. The Nov bird seems to have a generally larger eye with less space between eye and forehead. These comparisons support the idea that they are different individuals, but of course the slightly different photo angles and my own measurement error might be throwing things off.
As someone who also saw both birds, I’ll throw out an additional thought: the homeowners in this case felt their bird became MUCH more wary and skittish (essentially unapproachable) after it went through the banding process, but the arboretum bird, as you so indicated, seemed largely unfazed by human traffic.
(BTW, there was even a 3rd Chapel Hill hummer this summer, but I don’t believe the homeowners wanted to draw attention to it.)
aaack! correction: I meant “this winter” of course; not “this summer”
Difficult question in spite of the amazing pictures. They both might be the same bird. On the first picture, you can see four green iridescent feathers on the lower back to the right of the folded wing that form an almost perfect diamond/square shape. And on the second picture, I think I can see a similar configuration of shiny feathers, albeit more subtle (feather wear? angle to camera?). However, I have no idea how common such patterns are on hummers and how likely it is that two separate hummers would show such a configuration of shiny feathers.
If there are two, I kindly request to send one over as a vagrant to Germany. Here’s my backyard’s adress …
Hi Nate,
So many thanks for visiting our backyard last November and sharing your extensive knowledge about our young male rufous, the one in your first photo above. We named him Hummfree. From four feeders in our yard, he fed regularly each day from November through Feb. 2 (3:00 PM last seen).
As soon as I saw the early photos of the Coker Arboretum imposter, I knew he was not Hummfree.
Next year when Hummfree returns,though, he’ll be harder to recognize, even for me. But no matter. At that time, we’ll welcome him and you back to our yard.
Sharon Kirk, foster mom
Chapel Hill
Weight: 3.65g
Susan banded Hummfree (Rufus in the first photo above) on Jan. 12, 2012. These are the measurements I jotted down:
Wing length: 38.44mm
Tail length: 28mm (notched tail feather second from end indentifies a Rufus hummingbird)
Bill: 17.52mm (bill is smooth indicating he was hatched early last summer)
Number of gorget feathers: 11
@Dawn- Great! Feel free to leave the link here.
@Alan- That’s certainly a theory. Because so many of them are banded we know that many birds return year after year, and you’d have to think that without feeders those birds wouldn’t have made it so long.
@Mike – Luck and good light.
@Allen- Fantastic! Thanks for the information!
@Rob- One in south Durham was reported to eBird too.
@Jochen- Interesting thoughts. Having had limited experience with Rufous Hummers, I can’t say either.
@Sharon- Thanks! And thanks for being such a gracious host!