Bill much longer than the head, straight, compressed, tapering to a point, the mandibles nearly equal. Upper mandible with the dorsal line nearly straight, the ridge broad and slightly convex at the base, narrowed towards the end, a groove from the base to two-thirds of the length, beneath which the sides are convex, the edges thin and sharp, with a notch on each side close to the sharp tip. Nostrils basal, linear, longitudinal, with a membrane above and behind. Lower mandible with the angle extremely narrow and elongated, the dorsal line beyond it ascending and almost straight, the edges sharp and slightly inflected, the tip acuminate.
Head rather small, oblong, compressed. Neck very long and slender. Body slender and compressed; wings rather large. Feet very long; tibia elongated, its lower half bare, very slender, covered all round with angular scales, of which the posterior are scutelliform; tarsus elongated, slender, compressed, covered anteriorly with numerous scutella, laterally and behind with angular scales. Toes of moderate length, rather slender, scutellate above, reticularly granulate beneath; third toe much longer than second, which is very little longer than fourth, the hind toe much shorter but strong; claws of moderate size, rather strong, arched, compressed, rather acute, that of the hind toe much larger, the edge of that of the third regularly pectinated.
Space between the bill and eye, and around the latter, bare, as is the lower half of the tibia. Plumage soft, generally loose. Feathers of the upper and hind part of the head elongated, tapering, decurved, about six of them larger and much longer; of the sides, and especially of the lower part of the neck, also much elongated and narrow. The feathers of the fore part of the back long and narrow-pointed, those behind extremely elongated, with long loose threadlike barbs; the rest of the back with short soft feathers. Wing of moderate length; primaries tapering but rounded, the third longest, second very little shorter, first and fourth about equal; secondaries broad and rounded, some of the inner as long as the longest primaries, when the wing is closed. Tail very short, small, slightly rounded, of twelve rather weak feathers.
Bill brownish-black on the greater part of the upper mandible, and on the sides of the lower mandible towards the point; the rest yellow, as is the bare space before and around the eye. Iris bright red. Feet light yellowish-green, the anterior scutella dusky, as are the claws. The general colour of the upper parts is light purplish-blue; the elongated feathers of the head and hind neck above of a fine reddish-purple, as are those of the lower part of the neck; the six longest feathers of the head white. The long loose feathers of the back dull purplish-yellow, paler towards their extremities. Throat white, its lower part chestnut; a line of white all the way down the fore part of the neck; the longer feathers of the fore part of the breast dusky blue on their inner webs. The breast, abdomen, tibiæ, and under wing-coverts, white; the lower tail-coverts tipped with blue.
Length to end of the tail 27 inches, to end of wings 28, to end of claws 34 1/2; extent of wings 37; loose feathers from 4 to 5 inches beyond the tail; wing from flexure 10 3/4; tail 3 1/2; bill along the back 4, along the edges 5; bare part of tibia 2 1/4; tarsus 4 1/8, middle toe 2 1/2, its claws 1/2. Weight 1 lb.
The Adult Female is precisely similar to the male.
The Young, when newly hatched, are covered above with pale purplish-grey down, which is of greater length on the head, as in other species.
The young fully fledged have the neck and fore part of the back light brownish-red, the throat and lower parts white, as is the hind part of the back; the quills, larger wing-coverts and tail, light purplish-blue. The feathers of the head, neck and back are not yet elongated. The bill nearly as in the adult, but the legs deep greenish-olive.
After the first moult, the feathers of the head, neck and back, are a little elongated, and begin to be tinged with the colours which they have when the bird is full grown. The red of the neck is changed for tints of blue and purple, as is that of the back, although remnants of it are still seen. The fore part of the neck is white, mixed with brownish-red; the legs lighter.