The flight of the Night Heron is steady, rather slow, and often greatly protracted. They propel themselves by regular flappings of the wings, and, like the true Herons, draw in their head on the shoulders, while their legs stretch out behind, and with the tail form a kind of rudder. When alarmed they at times rise high in the air, and sail about for a while. They sail in the same manner before alighting on their feeding grounds, which they rarely do without having previously attended to their security by alighting on the neighbouring trees and looking about them. Their migrations are performed under night, when their passage is indicated by their loud hoarse notes resembling the syllable qua, uttered at pretty regular intervals. On these occasions they appear to fly faster than usual.
On the ground, this bird exhibits none of the grace observed in all the true Herons; it walks in a stooping posture, the neck much retracted, until it sees its prey, when, with a sudden movement, it stretches it out and secures its food. It is never seen standing motionless, waiting for its prey, like the true Herons, but is constantly moving about in search of it. Its feeding places are the sides of ditches, meadows, the shady banks of creeks, bayous, and ponds or rivers, as well as the extensive salt-marshes and mud-bars left exposed at low water; and I have observed it to alight in the ponds in the suburbs of Charleston towards evening, and feed there. In all such situations, excepting the last, this bird may often be seen by day, but more especially in the evening or morning twilight, wading up to its ankles, or, as we commonly say, its knee-joints. Its food consists of fishes, shrimps, tadpoles, frogs, water-lizards, and leeches, small crustacea of all kinds, water insects, moths, and even mice, which seem not less welcome to it than its more ordinary articles of food. When satisfied, it retires to some high tree on the banks of a stream or in the interior of a swamp, and there it stands, usually on one leg, for hours at a time, apparently dosing, though seldom sound asleep.
When wounded, this bird first tries to make its escape by hiding among the grass or bushes, squatting the moment it finds what it deems a secure place; but if no chance of a safe retreat occurs, it raises its crest, ruffles its feathers, and, opening its bill, prepares to defend itself. It can bite pretty severely, but the injury inflicted by its bill is not to be compared with that produced by its claws, which on such occasions it uses with much effect. If you seize it, it utters a loud, rough, continued sound, and tries to make its escape whenever it perceives the least chance.
The Night Heron undergoes three annual changes of plumage ere it attains its perfect state, although many individuals breed in the spring of the third year. After the first autumnal moult, the young is as you see it represented in the plate. In the second autumn, the markings of the neck and other parts have almost entirely disappeared; the upper parts of the head have become of a dull blackish-green, mixing near the upper mandible with the dull brown of the first season, while the rest of the plumage has assumed a uniform dull ochreous greyish-brown. In the course of the following season, the bird exhibits the green of the shoulders and back, the head is equally richly coloured, and the frontal band between the upper mandible and the eye, and over the latter, is pure white. At this age it rarely has the slender white feathers of the hind head longer than an inch or two. The sides of the neck, and all the lower parts, have become of a purer greyish-white. The wings are now spotless in all their parts, and of a light brownish-grey, as is the tail. The following spring, the plumage is complete, and the bird is as represented in the plate. After this period, with the exception of losing its long crest-feathers after the young are hatched, it retains its colouring. No difference can be observed in the tints of the sexes, but the male is somewhat larger.
A very considerable difference in size is observable at all seasons in birds of this species. Some that are fully feathered, and therefore at least three years old, measure as much as four inches less than others of the same sex, and weigh less in proportion. These circumstances might suffice with some naturalists to attempt to form two species out of one, but in this they would certainly fail.
In the neighbourhood of New Orleans, and along the Mississippi, as far up as Natchez, the shooting of this species is a favourite occupation with the planters, who represent it as equalling any other bird in the delicacy of its flesh.
The frog, of which I have introduced a figure, is common in the retired swamps which the Night Heron frequents, and is often devoured by it. The flowering plants which you see, are abundant in the States of Georgia and South Carolina, as well as in the Floridas.
Ardea Nycticorax, Linn. Syst. Nat. vol. i. p. 235.—Lath. Ind. Ornith. vol.ii. p. 678.—Ch. Bonaparte, Synops. of Birds of the United States, p. 306.
Night Heron, or Qua Bird, Wils. Amer. Ornith. vol. vii. p. 3, pl. 51, fig. 2. Adult. Fig. 3. Young.
Qua Bird, or American Night Heron, Ardea discors, Nuttall, Manual, vol. ii. p. 54.