Dacnis lineata is one of the tiniest members of the Tanager family (Thraupidae). Like most the tanegers its brightly colored. Male Black-faced Dacnis are turqouise-blue, with a white tummy, black wings and a black bandit's mask. On the other hand females and juveniles are olive-green color. Adult male and female have startling yellow eyes, blackish legs, and a sharp black beak (Isler and Isler 1987).
This little beak is perfectly suited for gleaning tiny bugs from leaves and flowers, as well as for stealing sips of nectar when it's able. Dacnis lineata is a agile flier, and they have a short, conical,thin and very pointed bill and bright yellow iris. They also posses a black bill and blackish legs.