About Heliomaster furcifer (Shaw, 1812)
The blue-tufted starthroat (Heliomaster furcifer) measures 12.6 to 13 cm (5.0 to 5.1 inches) long and weighs 5 to 6.5 g (0.18 to 0.23 oz). All subspecies of both sexes have a long, decurved black bill and a small white spot behind the eye. Both sexes also have a forked tail, though the female's tail is less deeply indented than the male's.
Breeding-plumage males have an emerald green crown, nape, and upper back; the remainder of their upperparts are shining coppery green. Their throat is glittering violet, and their underparts plus the elongated feathers on the sides of the neck are iridescent ultramarine. The upper side of their tail is dark green, while the underside is blue-green. Non-breeding males are grayish on the underside, just like females.
Females have coppery green upperparts. Their throat and underparts are gray, with a white line running down the middle of the belly and green spots on the flanks. The upper side of the female's tail is bronze green with black tips on the central feathers; the underside is shining blue-green with white tips on the outer feathers.
The core of the blue-tufted starthroat's range covers eastern Bolivia, southern Brazil, Paraguay, northern Argentina, and northern Uruguay. It has also been recorded in Colombia and Peru, and there is one undocumented sighting from Ecuador. The species inhabits open landscapes including forest edges, cerrado, and grasslands.
