Last Monday morning in Pisté again the cibers opened late and then my server in the US went down, so yet again I found myself wandering through town until the cyber-world got itself together. On a power line beside a dirt road I saw the flycatcher shown below:
To birders in western North America this looks a lot like their Western Kingbird. However, that species' tail is squared and has white outer tail-feathers, while this one's tail is forked and lacks the white tail-feathers. Western Kingbirds don't occur in the Yucatan.
In most of Mexico this common power-line-sitter would be quickly identifiable as the Tropical Kingbird. However, Along the Gulf Coast and here in the Yucatán there's a look-alike species, the Couch's Kingbird, of which Howell in A Guide to The Birds of Mexico and Northern Central America writes that it is "Rarely distinguishable in the field from Tropical Kingbird except by voice."
Three winters ago at San Juan Hacienda near Telchac Pueblo not far from the Gulf Coast both species were common and their calls really were different and easy to distinguish, and I never could separate the two species just by appearance. Unfortunately, the bird in Pisté wasn't saying a word last Monday.
Some authors lump the two forms under the Tropical Kingbird, so at least in that broad sense we can accurately say that in the picture is shown a Tropical Kingbird, TYRANNUS MELANCHOLICUS -- though it may be subspecies couchii.
Tropical Kingbirds are distributed from Mexico to central Argentina, but couchii occurs only from southern Texas along the Gulf Coast to northern Guatemala, including the Yucatán.