Volume Ii Part 15 (1/2)

It lays four eggs, large for the size of the bird, oval in shape, and white in colour, thickly blotched with dull red.

The preying habits of the Little Kestrel are similar to those of the Orange-chested Hobby; it haunts farm-houses and plantations, and spends a great deal of time perched on some elevation watching for its prey, and making sudden dashes to capture it by surprise. But though not bold when seeking its food, it frequently makes violent unprovoked attacks on species very much larger than itself, either from ill-temper or in a frolicsome spirit, which is more probable.

Thus I have seen one drive up a flock of Glossy Ibises and pursue them some distance, striking and buffeting them with the greatest energy. I saw another pounce down from its perch, where it had been sitting for some time, on a female skunk quietly seated at the entrance of her burrow, with her three half-grown young frolicking around her. I was watching them with intense interest, for they were leaping over their parent's tail, and playing like kittens with it, when the Hawk dashed down, and after striking at them quickly three or four times, as they tumbled pell-mell into their kennel, flew quietly away, apparently well satisfied with its achievement.

306. ELa.n.u.s LEUCURUS (Vieill.).

(WHITE-TAILED KITE.)

+Ela.n.u.s leucurus+, _Scl. et Salv. Nomencl._ p. 121; _iid. P. Z. S._ 1869, p. 160 (Buenos Ayres); _Durnford, Ibis_, 1877, p. 188 (Buenos Ayres); _White, P. Z. S._ 1882, p. 623 (Buenos Ayres); _Barrows, Auk_, 1884, p. 111 (Entrerios); _Doring, Exp. al Rio Negro_, p. 50 (Pampas); _Sharpe, Cat. B._ i. p. 339; _Withington, Ibis_, 1888, p. 470 (Lomas de Zamora).

_Description._--Above grey; lesser wing-coverts and scapulars black; tail white, two central rectrices grey: beneath white; bill black; feet yellow; claws yellow: whole length 145 inches, wing 110, tail 70. _Female_ similar, but rather larger.

_Hab._ Central and South America.

This interesting Hawk is found throughout the Argentine Republic, but is nowhere numerous. It also inhabits Chili, where, Gay says, it is called _Bailarin_ (dancer) on account of its aerial performances. It is a handsome bird, with large ruby-red irides, and when seen at a distance its snow-white plumage and buoyant flight give it a striking resemblance to a gull. Its wing-power is indeed marvellous. It delights to soar, like the Martens, during a high wind, and will spend hours in this sport, rising and falling alternately, and at times, seeming to abandon itself to the fury of the gale, is blown away like thistle-down, until, suddenly recovering itself, it shoots back to its original position.

Where there are tall poplar trees these birds amuse themselves by perching on the topmost slender twigs, balancing themselves with outspread wings, each bird on a separate tree, until the tree-tops are swept by the wind from under them, when they often remain poised almost motionless in the air, until the twigs return to their feet.

When looking out for prey, this Kite usually maintains a height of sixty or seventy feet above the ground, and in its actions strikingly resembles a fis.h.i.+ng gull, frequently remaining poised in the air with body motionless and wings rapidly vibrating for fully half a minute at a stretch, after which it flies on or dashes down upon its prey.

The nest is placed on the topmost twigs of a tall tree, and is round and neatly built of sticks, rather deep, and lined with dry gra.s.s. The eggs are eight in number, nearly spherical, the ground-colour creamy white, densely marked with longitudinal blotches or strips of a fine rich red, almost like coagulated blood in hue. There is, however, great variety in the shades of the red, also in the disposition of the markings, these in some eggs being confluent, so that the whole sh.e.l.l is red. The sh.e.l.l is polished and exceedingly fragile, a rare thing in the eggs of a raptor.

An approach to the nest is always greeted by the birds with long distressful cries, and this cry is also muttered in the love-season, when the males often fight and pursue each other in the air. The old and young birds sometimes live together until the following spring.

307. ROSTRHAMUS SOCIABILIS (Vieill.).

(SOCIABLE MARSH-HAWK.)

+Rostrhamus sociabilis+, _Scl. et Salv. Nomencl._ p. 121; _iid. P. Z.

S._ 1869, p. 160 (Buenos Ayres); _Durnford, Ibis_, 1877, p. 188 (Buenos Ayres); _Gibson, Ibis_, 1879, p. 413 (Buenos Ayres); _Withington, Ibis_, 1888, p. 470 (Lomas de Zamora). +Rostrhamus leucopygus+, _Sharpe, Cat. B._ i. p. 328. +Rostrhamus hamatus+, _Burm. La-Plata Reise_, ii. p. 435 (Rio Parana).

_Description._--Blackish slate-colour; head and wing-feathers black; rump white; tail white, with a broad band occupying the apical half, but leaving the tail end greyish; bill orange, apical half black; feet orange-brown, claws black: whole length 170 inches, wings 130, tail 75. _Female_ similar, but rather larger.

_Hab._ South America.

This Hawk in size and manner of flight resembles a Buzzard, but in its habits and the form of its slender and very sharply hooked beak it differs widely from that bird. The name of Sociable Marsh-Hawk, which Azara gave to this species, is very appropriate, for they invariably live in flocks of from twenty to a hundred individuals, and migrate and even breed in company. In Buenos Ayres they appear in September and resort to marshes and streams abounding in large water-snails (_Ampullaria_), on which they feed exclusively. Each bird has a favourite perch or spot of ground to which it carries every snail it captures, and after skilfully extracting the animal with its curiously modified beak, it drops the sh.e.l.l on the mound. When disturbed or persecuted by other birds they utter a peculiar cry, resembling the shrill neighing of a horse. In disposition they are most peaceable, and where they are abundant all other birds soon discover that they are not as other Hawks are and pay no attention to them. When soaring, which is their favourite pastime, the flight is singularly slow, the bird frequently remaining motionless for long intervals in one place; but the expanded tail is all the time twisted about in the most singular manner, moved from side to side, and turned up until its edge is nearly at a right angle with the plane of the body. These tail-movements appear to enable it to remain stationary in the air without the rapid vibratory wing-motions practised by _Ela.n.u.s leucurus_ and other hovering birds; and I should think that the vertebrae of the tail must have been somewhat modified by such a habit.

Concerning its breeding-habits Mr. Gibson writes:--”In the year 1873 I was so fortunate as to find a breeding colony in one of our largest and deepest swamps. There were probably twenty or thirty nests, placed a few yards apart, in the deepest and most lonely part of the whole 'canadon.'

They were slightly built platforms, supported on the rushes and two or three feet above the water, with the cup-shaped hollow lined with pieces of gra.s.s and water-rush. The eggs never exceeded three in a nest; the ground-colour generally bluish white, blotched and clouded very irregularly with dull red-brown, the rufous tint sometimes being replaced with ash-grey.”

308. SPIZIAPTERYX CIRc.u.mCINCTUS (Kaup).

(SPOT-WINGED FALCON.)

+Falco circ.u.mcinctus+, _Scl. Ibis_, 1862, p. 23, pl. ii.

+Spiziapteryx circ.u.mcinctus+, _Scl. et Salv. Nomencl._ p. 122; _White, P. Z. S._ 1882, p. 623 (Catamarca); _Sharpe, Cat. B._ i.

p. 371. +Falco punctipennis+, _Burm. J. f. O._ 1860, p. 242.

+Hemiierax circ.u.mcinctus+, _Burm. La-Plata Reise_, ii. p. 438.