Yellow warbler foraging with unknown warbler - Indianapolis (1 Viewer)

[ThrottleItOut]

Sorry for the photo quality - taken through double pane glass in the rain. Photo was taken today (July 8).

I'm confident that the bird in the third photo is a yellow warbler. The other bird however appears to also be a yellow warble except for the distinct black cap. I observed both birds foraging for insects together for some time, the cap appears to be a distinct part of the plumage, not an unusual photo artifact. Closest I can come up with is a Wilson's, but the body shape seems wrong and the location is wrong for this time of year. Any thoughts?

EDIT: Maybe it is a yellow warbler but with some sort of tree sap/mud/etc? Only other thing I can think of is that it hybridized with another warbler, but that seems improbable.

 

[KenM]

An odd looking bird indeed, with a symmetrical black/dark crown stripe where there should be yellow.
Agree, in all other departments it shouts Yellow Warbler which I’m sure it is…as nothing else matches, as to why….I don’t have a clue, and imo there would be no hybridisation, as there’s nothing else that might fit, apart from Yellow Warbler. 😮

Cheers

 

[njlarsen]

The first image seems to show a strange angle on an ovenbird.
Niels

 

[Butty]

ovenbird

Underparts entirely wrong, no malar stripe, etc.

 

[AveryBartels]

I think the theory of wet plumage/sap etc. is the most likely to explain the apparent dark cap. In the second image you can see that the crown is "wetted down" with something. Otherwise, it looks fine for a Yellow Warbler.

 

[ThrottleItOut]

Thanks everybody. I think it was just something dark on the feathers, as I saw what was likely the same pair of birds the next day (I live in a pretty urban area so warblers aren't a very common sight in my back yard). See additional photos from the next day - definitely yellow warblers.