Ak Yanaklı Bitkuşu Polioptila albiloris

Tiny gray and white bird with cocked tail. Common in tropical dry forest and scrub of Pacific lowlands. Male has a black cap, solid in breeding season, but with narrow white eyebrow in non-breeding season. Female has gray cap with narrow white eyebrow year-round. Told from Blue-gray Gnatcatcher by face pattern: Blue-gray has a white eyering, not a white brow.