Mystery Bird: Least Flycatcher, Empidonax minimus

Well, the genus seems relatively clear, based on the silhouette and general plumage features, but I'm not going to be able to go beyond that with any confidence.

Based on the date and location, and with a little help from the ongoing effects of anthropogenic climate change to shift this guy's range a bit north since my Sibley's range maps were printed, I guess I'll go with the one whose specific epithet corresponds with my degree of certainty.

While eyering, lighter colored lower mandible, and black smudge below the second wingbar leads me to think this is a ruby crowned kinglet.

Is this what David would describe as a "greenish mosquito king"? I still haven't found a decent book for identifying this very difficult group of birds without hearing them, is there one?

LOL John, surely you don't think this a Jamaican Vireo (modestus)!

Ken, I know the black smudge to be a key mark below the second wingbar on a Ruby-crowned Kinglet- is the eye ring complete or broken? If broken, then you're on track... however I would expect the bill to be a uniformly dark color and not bicolor, unless this is a Winter characteristic of which I am ignorant...

I'm about to run off to teach Chaucer, but I wanted to say to David. Do you mean by "broken" that there's a sort of upper brow either covering or disrupting the white eye ring? It looks sort of like there's a brow shadow, but not really a break. But I may be misunderstanding.

But now, sir, let me see what shall I sayn?

I mean that the eyering is broken at 12 o'clock and at 6 o'clock...

I'm not convinced that it's a Kinglet. The eye ring isn't broken, and the bill is much broader than I'd expect from a Kinglet, and also I wouldn't expect the mandible to be pale like that.

I agree with John's ID, assuming I'm interpreting his clue as to the specific epithet correctly. The location is the only thorn in this ID though; according to Sibley Texas is just in the migration range, and according to Nat Geo the winter range doesn't quite make it up to TX (though it could be expanding northward, or this could simply be a vagrant).

The primaries appear to be fairly short, though with their terminus behind the twig it's difficult to say conclusively. Also the bold eye ring, short bill (with pale mandible), and the overall color all lead me to lean toward this ID despite the problems with range. But yeah, difficult genus so my confidence in this ID isn't exactly high.

On a related note, this is my first time posting here though I'm a somewhat frequent lurker and fairly new to birding; how long should we typically wait before outright stating an answer?

Ken, I feel a major mea culpa coming on here ....

I go and tell everyone about that secondary bar, and that I don't know of any other bird that has it,

And Grrl immediately finds another bird that shows it. (Well done, actually.)

Just checked Sibley -- he shows flycatchers with that mark as well, only he doesn't bother to mention it. And I checked my handful of Empy photos -- yep, it's there. Ah, well...

In a poor attempt at defense -- it doesn't show up in Vireos, at least. Thick-billed appears to have a dark base to the secondary edges, but doesn't show a distinct edge to them. The rest look like any edging extends the whole length of the feather.

Brian -- for birds this hard, probably doesn't hurt to call it right away. Otherwise ... I'm sure Grrl will correct me if I mess this up, but the rule of thumb I usually use is that if I'm dead certain, I'll wait for others (at least for a day). If I'm not really sure, sometimes putting a name out there is a good way to get some discussion going.

In any case, I'm sure you and John got this one to genus, but I would probably go for a different species. I'm thinking about Hammond's -- I know it's out of range, but so is any Empy right now.
It seems to me that the bill is maybe a bit darker below than a Least would show and the primary extension seems a bit long for a Least. Also, Least molts after fall migration, Hammond's before. Which should mean that Hammond's is more worn by this time than Least is.

Having said all this, I wouldn't report this bird as more than Empy sp. without either measurements or tape recordings.

So John, until I get home to see this for myself, I assume you think this may be a Pacific-slope Flycatcher, Empidonax difficilis? (olive color, wingbars, eyering, bicolor bill)

In fact there are records of this (or it could have been a Cordilleran, occidentalis) at Anahuac in 1996, Galveston in 2001, and Brazos Bend in 2001...

Paul,

Ken and Brian describe the lower mandible as "lighter colored" or "pale" and I understood one of the distinguishing marks on a Hammond's to be a darker lower mandible?

generally, i hope that paul, david and adrian will help others to make the ID for the first 24 hours after the image has been published, then it's fair game for them. beginning and intermediate birders can name the bird at any time, but i hope they check back since paul, david and adrian will be there, making useful comments that will help you if your original ID was not correct.

David -- the lower mandible definitely shows some orangey color. Compared to, say, a kinglet's bill, or that of a phoebe, it's definitely not a 'dark' bill.

In the context of what we expect from an Empy? Well, it doesn't look as bright as a Willow or an Acadian. Since we're only looking at the side of the bill, there's definitely some room for interpretation here. And I think John's referring to a different species. His certainty regarding the ID, not a description of the bird itself.

Mostly because this bird seems to be entirely white or gray underneath. Any yellow is limited to the very rear of the flanks, in the shadow of the primaries. And E. difficilis (or occidentalis) should show some yellow on the throat and belly at just about any point in the year.

Of course, when it comes to these guys (especially out of range/season), anyone who's really definite about an ID is probably wrong. (Except maybe for Buff-breasted)

Oh, and thanks, Grrl, for pronouncing our comments 'useful'.

paul: i love reading your discussions. you all are helping me refine my own birding skills, too.

I think the upright posture eliminates both the vireos and the Kinglets. It shows all the aspects of a Flycatcher of that group known as Empy's. (very difficult to pin down from a photo).

LOL Paul, I was giving John the benefit of the doubt which means he mas a "minimal" confidence in his ID!

But it does sound to me that the orange lower mandible with white or gray underneath (and olive upperparts, white eye ring, white/light wingbars) fits his choice and eliminates Hammond's because of the bill, eliminates Pacific-slope and Cordilleran because of the lack of yellow on the throat/belly as you indicated, and if you can see the throat/belly then I assume both Yellow-bellied and Acadian would also be eliminated because of the lack of yellow below (and you could therefore count/discount Hammond's again if the breast was dark)... the length of tail might include or eliminate Willow or Alder which would also show more brown above than olive... if this is John's ID I am troubled by your description that it's bill looks too long because of all of the empis, this is the smallest with the smallest bill- but I do remember a prior discussion suggesting we don't look at the size but how large it makes the head look...

Ahh, my first impression is as I think where we were going, but I am not that experienced with empis so let's try the "sweet" approach!

Cornell always stresses habitat, song, and then range before narrowing down to species⦠I donât think we have enough information on habitat, certainly we canât hear it, so we can start with range- I donât see any problem for the Least as it is recorded by the Houston Audubon Society as quite common in both the Spring and Fall migrations, as are the Acadian and Yellow-bellied, followed by the "occasional" Alder which is in turn more plentiful than the Willow⦠as âcircumgulfâ migrants (i.e. hugging the coast), both the Yellow-bellied and Least are more plentiful in the Fall return migration than in the Springâ¦

my new (!) Peterson Advanced Birding chapter on empis quite clearly states to use âa large dose of cautionâ with empis outside their range- the Hammondâs is well outside range and although the difficilis/occidentalis records were verified by call and not just sight (with reference to a record of a Pacific-slope making it to southern Louisiana) they are possible but a bit of a stretchâ¦

it also states what not to look for and includes not considering yellowness on the belly because they all can show this, not to consider the pale lores, not to consider the pale outer webs on the outermost tail feathers, or if sighted in the field, not to consider wing and tail action- at most they may be minor supporting charactersâ¦

therefore I believe our list of possibles can really only include Acadian, Yellow-bellied, Alder, Willow, and last but not least Least

My immediate gut feeling upon seeing this photo was that it looks exactly like one of the signature birds in my summer woods, along with the red-eyed vireos and ovenbirds.

So, I'm going to go out on a limb here and say, "Chebek...Chebek."

Of the five I have, what we should be considering includes the pattern of the lower mandible (apparently, if seen from directly above or below, we would get the number one field mark based upon width, but we can't estimate that here), primary extension, overall proportions, and then plumage considerations...

Lower mandible: the Acadian has the largest bill with the lower mandible almost always entirely pinkish-yellow; the Yellow-bellied has a bill large compared to it's size with the lower mandible entirely orange-yellow; the Alder/Willow complex have heavy bills with the lower mandible usually entirely yellowish pink sometimes with a dusky tip; and the Least looks small-billed with the lower mandible mostly or entirely orange-yellow sometimes with an ill-defined dusky tip... I think this favors either the Yellow-bellied or the Least

Primary extension (and overall shape/proportions): the Acadian has the longest primary extension of any empi and the tail often looks wide; the Yellow-bellied has medium prmary exetnsion and appears large-headed and short-tailed; the Alders/Willows have long primary extensions with moderate length but broad-looking tails; and the Least usually has short primary extensions and has a round large-looking head... again, I think this rules out Acadian, Alder, and Willow

Key Plumage: because they moult in late Winter, characteristic Yellow-bellied coloring is faded by now with yellow tones subdued and appearing grayish-white below but with a distinctive grayish-yellow throat and greenish wash to the sides of the breast; with the Least also appearing very worn, drab above and very pale below, but having a whitish throat contrasting with darker face...

so my vote is for... John!

LOL lectric lady, the second syllable of the short and snappy che-beck being a little higher-pitched and more emphatic!

I don't think we'd hear a che-bunk, a peet-sah (if you're ever in the DC area, try Vace's in Cleveland Park for the best anywhere!), or a three-syllabled fee-bee-oh or fitz-be-yew!

As Adrian has mentioned, it definitely does not appear to be a kinglet or vireo. It looks like its from the Flycatcher family. Most ruby-crowned kinglets have a hint of bright yellow on their outer primaries and outer edges of tail feathers. Also, this bird appears to be larger than a kinglet and like most said, the eye ring isn't broken. This bird shows more of an olive green shade than gray which eliminates the possibilities. With the two whitish wingbars clearly visible and the thin white eye ring as described by Cornell's Lab of Ornithology, I have it between a Willow Flycatcher and Alder Flycatcher. The picture is from Texas so a Willow Flycatcher would be the most obvious choice because of its wide distribution through Texas as shown on Cornell's Lab of Ornithology site. But to support my answer, I believe its a Willow Flycatcher because Alder's tend to have darker colored legs and feet at times and this bird's feet appear slate gray.

Katie~

I am having trouble making out the feet. Is it a foot, or a bump on the twig of the tree? I'm also curious why you eliminate the Least? It could be in Texas at that time too.

As an aside, pictures can be so valuable. Imagine being in the field, trying like crazy to keep the %&*# flycatcher in the binoculars and being able to say, "the bird's feet appear to be slate gray."

I consider myself very lucky to find the whole bird for a nanosecond.

Hi Katie,

I think if you were to take a closer look at the primary extensions- how far the primaries extend past the secondaries (in the photo above I think we can estimate accurately by simply following the edge of the outer primary and see that it probably ends just as it is masked by the branch) you would perhaps notice that both the Willow and Alder Flycatchers have greater extensions than the Least (note also the dark legs on the attached Willow- I'm not sure leg color in empis is a valid mark to use)- they also give the impression in the Least that the secondaries are "stacked up"...

Willow Flycatcher

Alder Flycatcher

Least Flycatcher

Okay, David, you've convinced me -- probably Least. The question of range and whether it can be used to exclude any species in this case interests me. By everything we can see, Least doesn't winter in Texas, with Houston quite a ways from the closest normal winter range in NE Mexico. (Actually, Hammond's winters in the same area). Given that the photo was taken in January, either the range maps are pretty out-of-date (possible) or this is a notable record. So: I guess the question is, for this particular combination of species, which is more likely, an out-of-season late stayer, or an out-of-range and -season vagrant. More generally, although I think we have a handle on likelihoods of many species showing up in weird places, do we really have a good feel for species occurring at weird times?

Katie, you are one adventurous birder. I wouldn't even make an attempt at a Traill's without a recording. (For those really new to the sport, Traill's is the name for Willow and Alder before there was a Willow and an Alder).

Even with voices, they can be tricky. Here in Illinois we get breeding Willows, and Alders well into June. There have been suggestions of breeding Alders very close to my house, but the one definitively reported was later shown to be Willow. I ran into a similar situation last year -- I swear the first day they were giving Alder calls, the next they were plainly Willow. With practice the simple call notes are more useful, if you can hear them.

Here is what I hear outside my bedroom window on early morning summer dawns:

Fee-be? Fee-be!
Chebek..chebek..chebek
Fee-be? Fee-be!
Hey! Here am I! Look up! In this tree!
Teecher, Teecher, Teecher
Fee-be? Fee-Be!
No! Here! In this tree! Look up!
Chebek..chebek..chebek
Fee-be? Fee-be!
Teecher, Teecher, Teecher

Not that I am complaining.

What do you hear at your house?

@ Adrian, way back up there- sorry, I missed your comment earlier! Absolutely yes! A "lord of the gnats" (Empidonax) but I would probably have taken it a little further and referenced one of my favorite novels by William Golding- "I should have thought that a pack of British boys would have been able to put up a better show than that."

Hey Paul,

This is what the Peterson Advanced Guide says about range:

"records of Empidonax should never be accepted on the basis of sightings alone, regardless of how many or how skilled the observers... tape recordings of the song would be ideal, but vagrants do not often sing. Photographs taken from the field rarely show enough detail for certain identification (although when Greg Lasley found the first Hammond's Flycatcher for eastern Texas he took more than sixty close-up photos)... generally with a nonsinging empid, your only chance of confirming the record would be to have the bird mist-netted for careful measurement and photography in the hand"

of cuurse, earlier in the chaper it is written:

"if you reach the stage at which youfeel you can name eevery Empid yu see in the field, you are probably deluding yourself!"

I guess what steers me to accept the possibility of Least (as opposed to something like Hammond's) is that we do know it migrates through Houston in the Spring and Fall, specifically hugs the coast (as opposed to traveling trans-gulf), and that immatures leave considerably later than adults and makeup most of the Fall migration numbers, the only real difference between immatures and adults being buff wingbars and "buffy" tertial edgings (do we have that here?), and so the possibility of it overwintering does not seem too far-fetched- in support, records for February of 2008 when the temperatures reached as much as 20 degrees above normal, showed Least Flycatchers, Rose-breasted Grosbeaks, and Broad-winged Hawks still in south Texas, and Least Flycatchers in Nacogdoches in January of 2004, 140 miles NNE of Houston...

Sorry I'm a bit slow in commenting, but the glitch is back. OK so we agree it's an Empidonax, now does the grey (gray) on the nape and sides of the neck have any significance here? Does it eliminate any of the species mentioned so far? As the primary projection is partly hidden by the branch and tail length is also difficult to judge from this angle. What I'm getting at is how do we identify an out-of range/ out of season Empy without a) voice b) size comparison and c) in-hand measurements.
I agree it is most probably Least, but I can't rule out Acadian or Willow on the view we have here. What winter records are there for any of these species in Texas? And when does return migration start through there?
I think this ramble means I don't know what it is really!!

Adrian, I think we can rule out Acadian or Willow on the length of the bill. Certainly Acadian -- they're one of the longest billed Empys. David pointed out February records for Least Flycatchers in South Texas and a January record in SW Louisiana, so I suppose that's possible.

I think the passing references to possible anomalies due to climate chnage cannot be overlooked.

According to the 2009 Audubon Birds and Climate Change- Ecological Disruption in Motion:

"Analysis of four decades of Christmas Bird Count observations reveal that birds seen in North America during the first weeks of winter have moved dramatically northwardâtoward colder latitudesâover the past four decades. Significant northward movement occurred among 58% of the observed speciesâ177 of 305. More than 60 moved in excess of 100 miles north, while the average distance moved by all studied speciesâincluding those that did not reflect the trendâwas 35 miles northward. There was also movement inland, from warmer coastal states into areas not long accustomed to winter temperatures suitable for their new arrivals."

Thanks David! Didn't catch the primaries!