Mystery Bird: Prothonotary Warbler, Protonotaria citrea

I'll try a wild guess: Prothonotary Warbler. The fluffy white undertail coverts, short tail with white outer feathers, the dark wings, and the bright yellow on the underside all suggest this. The chestnut on the breast is, I hope, a result of shadowing.

I don't think Prothonotary warbler is a wild guess at all.

I remember being startled at how brilliantly colored the bird was--the guides don't do it justice. I remember the brilliant, deep yellow being washed with rust/orange, the one time I saw a singing male Prothonotary warbler in Northern Ohio (Crane Creek State Park/Ottawa NWR).

The short tail and orange chest and south Texas say Tropical Parula to me.

I can't quite see Tropical Parula -- the yellow on the undersides appears to continue below the legs, and the thighs are yellow -- both marks against either Parula. Certainly worth checking, though.