Unmistakable, long-tailed hummingbird with straight, short bill. Male has very long, brilliant blue tail and iridescent blue throat; female very different, with shorter, white-tipped tail and whitish underparts. Found alone inside humid forests or edges at low to mid heights in montane regions. Typical vocalizations are electric and short, repeated constantly. No similar species in its very limited range, though male very similar to more widespread Long-tailed Sylph. Endemic to the Turimiquire region of northeastern Venezuela.