A History of the Birds of New Zealand.
Stercorarius Antarcticus. — (Southern Skua.)
Stercorarius Antarcticus.
(Southern Skua.)
Lestris catarractes, Quoy et Gaim. Voy. de l’Uranie, Zool. p. 137 (1824).
Lestris antarcticus, Less. Traité d’Orn. p. 616 (1831).
Stercorarius antarcticus, Gray. Gen. of B. iii. p. 653 (1845).
Cataracta antarctica, Bonap. C. R. xlii. p. 770 (1856).
Megalestris antarcticus, Bonap. Consp. Gen. Av. ii. p. 206 (1857).
♀ ad. suprà sordidè cinerascenti-brunnea: subtus pallidior: scapularibus et tectricibus alarum paulló cinerascentialbido variis: pileo colloque longitudinaliter pallidé brunneo maculatis: collo postico flavicanti-brunneo terminato: remigibus et rectricibus obscurè nigris versùs basin albicantibus: rostro nigricanti-brunneo: pedibus nigris: iride nigrâ.
Adult, General colour dull cinereous brown, darker on the upper parts, but relieved by touches of grey and light brown, especially on the upper wing-coverts and scapulars; head and neck largely marked with pale brown; the feathers of the hind neck lanceolate in form, and with their terminal portion yellowish brown; quills and tail-feathers dusky black, white in their basal portion; in the closed wing the white is apparent on the primaries to the extent of an inch, but in the secondaries and tail-feathers it is concealed by the upper coverts. Irides and feet black; bill blackish brown. Total length 25 inches; wing, from flexure, 17; tail 7; bill, along the ridge 2·25, along the edge of lower mandible 2·5; bare tibia 1; tarsus 3; middle toe and claw 3·1; hind toe and claw ·5.
Young. A bird of the year captured by Mr. Drew at the Wanganui heads differs in having the general plumage slaty brown, the scapulars only having terminal patches of light yellowish brown and whitish grey. There are no lanceolate feathers on the neck, and the basal white spot on the primaries is concealed by the overlapping coverts. Bill uniform, bluish black.
Obs. The sexes are alike, but the amount of white on the primaries is variable, and some examples are more suffused with brown on the neck and upper surface than others. A specimen from Dusky Bay has the white alular spots very conspicuous even in the closed wing, and one from Stewart’s Island is much lighter than ordinary examples, having the entire plumage tinged with brown, and the feathers of the nape and mantle broadly margined with yellowish brown.
Mr. original description of this fine Skua was taken from a specimen procured by Sir James Hector, who furnished me with the following note respecting it:—“Female bird shot in Woodhen Cove, on the south side of Breaksea Sound. There was only one pair; both were shot, but one skin was destroyed. Several others were seen at sea in company with the Albatros.”
Numerous examples have since been obtained in both Islands.
I had a live one in my possession for several years, and as this bird afforded me an opportunity of observing the habits of the species, under new conditions of life, I will venture to reproduce here, with a few additions, an account of it which I communicated to the Wellington Philosophical Society in September 1878*:—
* Trans. N.-Z. Inst. vol. xi. pp. 373, 374.
* To the above full record of his life, I have nothing to add but a notice of his death, a year later, which appeared to be the result of sheer old age. His obituary was communicated to me by my wife in the following terms:—“Like a sensible bird he first had a hearty breakfast, then a bath, and then laid himself down in a comfortable place on the lawn and quietly died.”
On the range of the three allied species of this larger form of Skua, Mr. Saunders writes:—“The northern species, S. catarrhactes, whose breeding-range stretches from the coast of Norway, the Faroes, and Iceland, away through the Nearctic region/and the Pacific, appears to be nowhere numerically abundant, and is fast becoming exterminated in Europe…… It has occurred in California; but descending that coast, we find no trace of a large Skua until we enter the fish-abounding, and therefore Gull-frequented, waters of Humboldt’s Current, which cools the coasts of Chili and Peru throughout a width of about 300 miles, and sweeps outwards to diminish the natural heat of the equatorial Galapagos Islands. In these productive waters is found a large Skua, S. chilensis, separable from the northern S. catarrhactes by its brighter and more chestnut underparts and axillaries—differences which are constant, although it is true that they are merely those of colour. Its bill is perhaps a trifle more slender than that of the northern bird, a point which should be borne in mind, because on passing through the Straits of Magellan, where this species appears to stop, we come at once to another large Skua, S. antarcticus, which, although in such close geographical proximity to S. chilensis, yet differs far more from it than S. chilensis does from S. catarrhactes! The Antarctic Skua ranges from the Falkland Islands down to the edge of the pack-ice, the shores of New Zealand, and up to Norfolk Island, and thence by way of the chain of Kerguelen Island, St. Paul’s Island, the Crozets, &c., it reaches the Cape of Good Hope and, as a straggler, Madagascar. From the Cape it works round by Tristan d’Acunha and the South Atlantic islands, till the chain is completed at the Falklands again. S. antarcticus is a uniformly dusky bird, with stronger and shorter bill than either of its near relatives.” (Journ. Linn. Soc., Zool. vol. xiv. pp. 392, 393.)
The flight of this bird is heavy, and performed by slow regular flappings of the wings, with the shoulders much arched. It possesses, however, the faculty of turning quickly in the air, as I observed when the Gulls were in pursuit. On the wing the white mark across the primaries is very conspicuous, but it is not sufficiently apparent to distinguish the bird when the body is at rest.
In the Otago Museum there are two eggs of this Skua, which differ appreciably. Although of similar size, one is narrower or more elliptical than the other, measuring 3·1 inches in length by 2 in breadth; of a pale, creamy-brown colour, blotched all over the surface, and pretty equally, with blackish and purplish brown. On one side these blotches are confluent, and they are generally darker towards the middle circumference. This specimen was collected at Campbell Island. The other, which came from Macquarie Island, is more ovoid, measuring 3 inches by 2·2, and is of a dull olive-brown sparingly blotched with dark brown, the intervening spaces being marked with small, irregular spots of the same colour, more or less distinct.