[Marcel Gauthier]

Hello BF folks

For those of you they are familiar with Juvie Yellow-rumped Warbler, let's take a look at this one.. Check the tail under part color : black. I never see it before. or maybe I missed the ID.

More picture at http://www.notason.com/annexe/id18.htm

[prairiemerlin]

At first glance, I thought this was a Cape May Warbler. However, I think you are right; this is a Yellow-rumped Warber. The yellow side patch is apparent in the second photo, and the facial pattern is wrong for Cape May. Also, the bill is too heavy for a Cape May.

What I find interesting about this bird is that it has a yellowish throat. This makes it look like the "Audubons" sub-species. It doesn't seem to be a pure Audubon's, so it probably is an intergrade between the Audubon's and the Myrtle subspecies. That may explain why it looked odd to you.

[Thayeri]

It is a Yellow-rumped Warbler of the Myrtle Race. I agree with Brown Creeper on the yellow shoulders eliminating the potential confusion species of fall Cape May, and would add the tail spot would be much too short. I don't see a need however to hypothesize an intergrade with Audubon's that far east, the throat is not yellow, and Myrtle can have some buffy in the throat, particularly in the malar region of a fall adult male, where it is strongest in the photo. I think the unusual undertail / coverts appearance is a combination of perhaps somewhat shorter than average tail spots, and the unusual gap in the undertail coverts indicating that molting undertail covert feathers have not been replaced yet. Which makes the coverts look too short, and the tail projection too long.

Beyond that, it gets a bit tricky. Definitely not a first fall female -- not brown enough. The breast streaking is tricky, thin streaks would make me lean towards fall adult female or first fall male, but the streaking right down the middle of the breast is best for fall adult male. The extent of gray still remaining in the head and wing coverts, as well as the black lores and buffy in throat tip the scales, and make my vote for fall adult male Yellow-rumped that is still molting.

[Marcel Gauthier]

I got a private message suggesting a Kirtland's Warbler Juvie. The undertail color fit perfectly.

or maybe, an hybrid KIWA & YRWA??

[Thayeri]

Originally Posted by Marcel Gauthier

I got a private message suggesting a Kirtland's Warbler Juvie. The undertail color fit perfectly.

or maybe, an hybrid KIWA & YRWA??

In addition to being a very rare and endangered species that doesn't breed in Canada, Kirtlands has strongly yellow underparts except for the undertail coverts, in all plumages.

[Marcel Gauthier]

So... we got a YRWA with a uncommon undertail/covert black part... That's a ''primer' for me.

Thanks folks for comments.

[phlebas]

Hi Marcel! Looks like I got a similar bird in my area. I saw about four of them in the trees near a river and I wondered what they were. Then I saw this thread. I was fooled by the tail pattern too, and the broken eye ring. Ah well.

[Thayeri]

Hello Phlebas, your bird is indeed similar, but different enough to nicely illustrate the differences between molting fall Yellow-rumped, and molting fall Cape May Warbler, which is what you have. The amount of yellow in the underparts disqualifies Yellow-rumped, and the extensive streaking right through the ventral region is a good field mark for Cape May. Notice also that the streaking extends up the yellow throat to close to the eye, too far up for Yellow-rumped. Interesting that your bird's undertail has the exact same thing going on, with the missing molting feathers in the middle of the undertail coverts creating a gap like the Yellow-rumped, with that causing the coverts to look shorter, the tail projection longer, and the gap between coverts and tail spots to look artificially long. When you look closely you can see the difference between species here as well, as the coverts are washed yellow with "your" bird (likely exaggerated by the greenish light filtering through leaves), and the spots are distinctly longer as a percentage of the tail than in Marcel's bird, which is what you would expect in both cases.

[phlebas]

Interesting! Thank you Thayeri, your info is greatly appreciated. So much to learn about these little birds...

[Motmot]

I´m glad to say I fully agree with Thayeri on these birds.

[JANJ]

Spot on Thayeri, "Myrtle".
Obvious undertail covert loss revealing much of undertail base.
Age? confused here. If you look at the two pic. in Warblers (Dunn/Garrett) of the fall adult male and 1st fall male you will spot the diferences in median covert pattern between the two. On the fall ad. each covert are fully dark centered, while in the 1st fall individual there is a thin dark shaft streak surrounded by white. Not sure if this is a reliable character for Yellow-rumped. Tail tip shape seems unreliable in this species, but they look truncate and also primaries looks black! Isn´t there a moult contrast in this pic, the same bird.http://www.notason.com/annexe/2805ec80.jpg, or is it just the light?
http://collections.ic.gc.ca/warblers/ID/mywaid.htm
http://www.westol.com/~banding/Sprin...ril2ndHalf.htm
JanJ

[Thayeri]

Originally Posted by Motmot

I´m glad to say I fully agree with Thayeri on these birds.

LOL! Have you noticed, Motmot, that we almost always do agree on the birds with photos this good? It is the more marginal photos that require a good bit of interpretation, that seem to lead to enjoyable discussions...

And speaking of discussions, hello JanJ! Yes, this bird does appear to have some conflicting characteristics from an aging perspective. As I indicated above, I don't like the thinness of the breast streaks for adult fall male -- but at the same time, the streaking right down the center of the breast is better for adult than first fall male (or adult female). So, I went with the extent of the gray in the upperparts (a first fall male should be browner, as an adult male would be when molting is complete), as well as the black lores and partially buffy throat to say 4-1 characteristics for adult over hatch year, most likely an adult. If the second photo is the same bird, as appears likely, I would still strongly tilt towards adult, because even though there is more brown visible -- it should be there and getting stronger for a molting adult, but not that amount of gray for a first fall male.

The wing coverts are an interesting area, thanks for pointing out the particulars! Yep, the thin streaks look better for first fall. However, while I didn't mention it above, I thought that the bold whiteness of the wing bars was another argument for adult, as a first fall male should have more of a brown wash to them, and be lower contrast. They do a look a bit browner in the second photo side view, but then again, that is supposed to be happen as an adult male goes to fall plumage.

Conflicting evidence, and as Dunn and Garrett say, not all fall adult males can be separated from first fall males, and fall adult females overlap with first fall males as well... fun with fall warblers!

[Motmot]

Originally Posted by JANJ

Spot on Thayeri, "Myrtle".
Obvious undertail covert loss revealing much of undertail base.
Age? confused here. If you look at the two pic. in Warblers (Dunn/Garrett) of the fall adult male and 1st fall male you will spot the diferences in median covert pattern between the two. On the fall ad. each covert are fully dark centered, while in the 1st fall individual there is a thin dark shaft streak surrounded by white. Not sure if this is a reliable character for Yellow-rumped. Tail tip shape seems unreliable in this species, but they look truncate and also primaries looks black! Isn´t there a moult contrast in this pic, the same bird.http://www.notason.com/annexe/2805ec80.jpg, or is it just the light?
http://collections.ic.gc.ca/warblers/ID/mywaid.htm
http://www.westol.com/~banding/Sprin...ril2ndHalf.htm
JanJ

Hi JANJ. First prebasic moult on this species includes all median and usually all greater coverts. I don´t think the difference you mention is anything but individual variation. All the coverts we see on those pics are adult like. Primary coverts look very dark and with nice whitish margins (adult looking) and primaries are blackish. I guess it´s an adult but it could be a 1st year, a young bird with its flight feathers still looking very fresh. Rectrices shape, as you mention, aren´t easy to use for ageing this species, lots of overlap.
Saludos
Eduardo

[Marcel Gauthier]

Yop. The 3 photos at http://www.notason.com/annexe/id18.htm represent the same bird.

[Motmot]

[quote=Thayeri]LOL! Have you noticed, Motmot, that we almost always do agree on the birds with photos this good? It is the more marginal photos that require a good bit of interpretation, that seem to lead to enjoyable discussions...

Yessss! These good pics are easier to id to species level. Now comes age, sex etc to get in trouble again ha ha!

[JANJ]

[quote=Motmot]Hi JANJ. First prebasic moult on this species includes all median and usually all greater coverts. I don´t think the difference you mention is anything but individual variation. All the coverts we see on those pics are adult like. Primary coverts look very dark and with nice whitish margins (adult looking) and primaries are blackish. I guess it´s an adult but it could be a 1st year, a young bird with its flight feathers still looking very fresh. Rectrices shape, as you mention, aren´t easy to use for ageing this species, lots of overlap.
Saludos
Eduardo[/QUOTE


Yes Eduardo, your right, I have noticed all that.
JanJ