Probable Townsend’s Warbler hybrid, High Island – images and video

Probably the most interesting bird we saw in Texas was a Dendroica hybrid at Boy Scout Wood on 20th and 21st April; it had already been present for one or two days, and was provoking considerable debate. It showed very well at times, though, and when it got to within a few feet at Prothonotary Pond, Suzanne was stealthy enough to take the following video:

I also managed to get some images, albeit a bit ropey at high ISO settings. I’ve done some basic noise reduction to combat this, but not made any other adjustments.

At first sight, it appears pretty similar to a Townsend’s Warbler (a Pacific coast species that we’ve seen in British Colombia previously), but there are a few things wrong:

• most significantly, there is nowhere near enough yellow on the breast and upper breast for Townsend’s – just a hint of a lemon wash below the black throat
• there is a hint of a yellow wash around the vent, which should be clean white on Townsend’s
• the mantle is not particularly well streaked on the olive green ground colour
• the undertail doesn’t show any black streaking, as male Townsend’s should
• perhaps a bit more subjectively, the black mask is also rather diffuse, showing a small yellow ‘hole’ towards the back of the ear coverts.

It’s not a million miles from Black-throated Green Warbler, either, but:

• the black face mask is wrong
• the hint of black streaking on the mantle shouldn’t be there

So, when we left, I think the debate was leaning towards a Townsend’s x Black-throated Green Warbler, having previously considered Townsend’s x Hermit. The former combo is known to occur in British Columbia (see brief details and a pretty similar image >here<), so it’s definitely within the realms of possibility.

If anyone has anything further to add to the ID, please leave a comment!