Sao Francisco Black Tyrant

The Sao Francisco black tyrant is 16 to 16.5 cm (6.3 to 6.5 in) long. One female weighed 20.5 g (0.72 oz). Adult males are almost entirely shiny black. Their wings have a wide white band at the base of the primaries that is conspicuous in flight but usually hidden when perched. Adult females have a mostly brownish gray head and upperparts with a rufous-buff rump, uppertail coverts, and base of the tail. The rest of their tail is dark. Their wings are brownish gray with whitish edges on the innermost remiges and pale tips on the coverts that show as two wing bars. Voice: The Sao Francisco black tyrant's vocalizations are very poorly known. As of May 2025 xeno-canto had only two recordings of them; the Cornell Lab of Ornithology's Macaulay Library had one of those and five others. Males apparently give "very short and high-pitched notes".