About Fluvicola pica albiventer (Spix, 1825)
Fluvicola pica albiventer, the pied water tyrant, measures 12.5 to 13.5 cm long and weighs 11 to 16 g. Both sexes have prominent rictal bristles, a dark iris, a sharply hooked black bill, and black legs and feet. Adult males are mostly white, with a black hindcrown and nape, a mottled black and white back, black wings with small white tertial tips, a black tail with small white tips, and entirely white underparts. Females have brown mixed into the black on the hindcrown, nape, and back. Juveniles follow the adult pattern but are brown where adults are black. The pied water tyrant has a disjunct distribution that is not yet fully defined. All sources agree it occurs in eastern Panama, from northern and central Colombia into northwestern Venezuela, on Trinidad, and from eastern Colombia across northern Venezuela, the Guianas, to the mouth of the Amazon in extreme northern Brazil. There is disagreement about records outside these core areas. The IOC, Clements taxonomy, and the AOS North American Classification Committee do not list the species in any other countries. BirdLife International (BLI) adds Aruba, Bonaire, Curaçao, Ecuador, and Peru as locations where the species is resident. The IUCN, which typically uses BLI range data, lists it as resident in Ecuador and Peru, and as a vagrant in Aruba, Bonaire, Sint Eustatius, and Curaçao. Cornell Lab of Ornithology's Birds of the World notes a minor presence in Ecuador and Peru, citing refereed papers, other published works, and eBird data. The AOS South American Classification Committee lists the species as confirmed in Peru and vagrant in Ecuador; neither this committee nor other sources mention occurrence on other Caribbean islands. The pied water tyrant primarily lives in freshwater marshes and along lake and pond margins; it also occurs in nearby grasslands and gardens. It is found mostly below 450 m in elevation, but reaches 1,000 m in Colombia.
