Volume Ii Part 19 (1/2)

It comes as far south as Buenos Ayres, but is only a summer visitor there, and very scarce. Having seen but little of it myself, I can only repeat Azara's words concerning it. He says it is common in Paraguay, going in pairs or families, and perches and roosts on trees, and when flying flaps its wings more rapidly than other Herons. It makes its nest on a tree, and lays two clear blue eggs.

On the Lower Uruguay, Mr. Barrows likewise found this species ”not common.” It was only seen a few times in November. ”Though most resembling the Night-Heron they were active by day, and when disturbed flew rapidly away from the streams and swamps towards the dry woods and hills.”

320. BUTORIDES CYANURUS (Vieill.).

(LITTLE BLUE HERON.)

+Butorides cyanurus+, _Scl. et Salv. Nomencl._ p. 125; _iid. P. Z.

S._ 1868, p. 145 (Buenos Ayres); _Durnford, Ibis_, 1878, p. 62 (Buenos Ayres); _Barrows, Auk_, 1884, p. 271 (Entrerios).

+Butorides striata+, _Baird, Brew., et Ridgw. Water-B. N. A._ i.

p. 50.

_Description._--Glaucous grey; beneath ashy; crown crested, black, with greenish gloss; neck beneath with a band of ferruginous spots, more or less mixed with black; wings greenish cinereous; wing-coverts edged with whitish; bill dusky green, feet ashy yellowish: whole length 140 inches, wing 65, tail 25. _Female_ similar.

_Hab._ South America.

The Little Blue Heron, though widely distributed, is not anywhere a common bird. I have always seen them singly, for it loves a hermit-life, and the feeding-ground it prefers is a spot on the borders of a marshy stream shut in and overshadowed on all sides by trees and tall rushes.

There the bird sits silent and solitary on a projecting root or dead branch; or stands motionless and knee-deep in the water, intent on the small fry it feeds on. For whole months it will be found every day in the same place. When intruded on in its haunt it erects the feathers of its head and neck, looking strangely alarmed or angry, and flies away uttering a powerful harsh grating cry.

Its nesting-habits I do not know; but Mr. Barrows says that it undoubtedly breeds near Concepcion on the Lower Uruguay, where it is abundant in spring and summer.

321. ARDETTA INVOLUCRIS (Vieill.).

(VARIEGATED HERON.)

[Plate XVII.]

[Ill.u.s.tration: ARDETTA INVOLUCRIS.]

+Ardetta involucris+, _Scl. et Salv. Nomencl._ p. 125; _iid. P. Z.

S._ 1869, p. 634; _Hudson, P. Z. S._ 1875, p. 624 (Buenos Ayres); _Durnford, Ibis_, 1877, p. 189, et 1878, p. 62 (Buenos Ayres); _Gibson, Ibis_, 1880, p. 159 (Buenos Ayres); _Barrows, Auk_, 1884, p. 271 (Entrerios).

_Description._--Above pale fulvous; narrow stripe on the nape black; front, stripe on the back of the neck, bend of wing, and outer secondaries chestnut-red; back striped with black; wing-feathers dark cinereous with red tips: beneath paler, nearly white on the belly; neck, breast, and flanks with brown stripes, darker in the centres; bill yellow; feet brown: whole length 130 inches, wing 50, tail 15.

_Hab._ Paraguay and Argentina.

The Variegated Heron is the least of the family to which it belongs, its body being no bigger than that of the Common Snipe; but in structure it is like other Herons, except that its legs are a trifle shorter in proportion to its size and its wings very much shorter than in other species. The under plumage is dull yellow in colour, while all the other parts are variegated with marks of fuscous and various shades of brown and yellow. The body is extremely slim, and the lower portion of the neck covered with thick plumage, giving that part a deceptively ma.s.sive appearance. The perching faculty, possessed in so eminent a degree by all Herons, probably attains its greatest perfection in this species, and is combined with locomotion in a unique and wonderful manner. It inhabits beds of rushes growing in rather deep water; very seldom, and probably only accidentally, does it visit the sh.o.r.e, and only when driven up does it rise above the rushes; for its flight, unlike that of its congeners, is extremely feeble. The rushes it lives amongst rise, smooth as a polished pipe-stem, vertically from water too deep for the bird to wade in; yet it goes up to the summit and down to the surface, moving freely and briskly about amongst them, or runs in a straight line through them almost as rapidly as a Plover can run over the bare level ground. Unless I myself had been a witness of this feat, I could scarcely have credited it; for how does it manage to grasp the smooth vertical stems quickly and firmly enough to progress so rapidly without ever slipping down through them?

The Variegated Heron is a silent solitary bird, found everywhere in the marshes along the Plata, as also in the reed-beds scattered over the pampas. It breeds amongst the rushes, and lays from three to five spherical eggs, of a rich lively green and beautiful beyond comparison.

The nest is a slight platform structure about a foot above the water, and so small that there is barely s.p.a.ce enough on it for the eggs, which are large for the bird. When one looks down on them they cover and hide the slight nest, and being green like the surrounding rushes they are not easy to detect.

When driven up the bird flies eighty or a hundred yards away, and drops again amongst the rushes; it is difficult to flush it a second time, and a third time it is impossible. A curious circ.u.mstance is that where it finally settles it can never be found. As I could never succeed in getting specimens when I wanted them, I once employed some Gaucho boys, who had dogs trained to hunt young Ducks, to try for this little Heron.

They procured several specimens, and said that without the aid of their dogs they could never succeed in finding a bird, though they always marked the exact spot where it alighted. This I attributed to the slender figure it makes, and to the colour of the plumage so closely a.s.similating to that of the dead yellow and brown-spotted rushes always found amongst the green ones; but I did not know for many years that the bird possessed a marvellous instinct that made its peculiar conformation and imitative colour far more advantageous than they could be of themselves.