A History of the Birds of New Zealand.
Phalacrocorax Imperialis. — (Emperor Shag.)
Phalacrocorax imperialis, King, Proc. Z. S. 1831, p. 30.
Phalacrocorax cirrhatus, Scl. & Salv. Ibis, 1868, p. 189.
Graculus carunculatus, Finsch, J. f. O. 1870, p. 375.
Phalacrocorax carunculatus, Scl. & Salv. Ibis, 1870, p. 500.
Phalacrocorax carunculatus, Buller, Birds of New Zealand, 1st edit. p. 332 (1873).
Graculus carunculatus, Sharpe, App. Voy. Ereb. and Terr. p. 34 (1875).
Phalacrocorax imperialis, Scl. & Salv. Proc. Z. S. 1878, p. 652.
Phalacrocorax cirrhatus, Hutton, Trans. N.-Z. Inst. vol. xi. p. 336 (1879).
Ad. pileo cristato cum collo postico, dorso postico, uropygio et supracaudalibus nitidè purpurascentibus: interscapulio, scapularibus alarumque tectricibus sordidè olivaceo-viridibus, illo purpurascente lavato, tectricibus alarum minimis interioribus albis, fasciam albam conspicuam formantibus: remigibus brunneis, secundariis olivaceo lavatis: caudâ sordidè nigrâ, rectricibus duabus centralibus medialiter cano lavatis, scapis ad basin albis: facie et collo lateralibus purpurascenti-nigris pileo concoloribus: corpore reliquo subtùs purè albo: hypochondriis imis purpurascenti-nigris: subalaribus brunneis: rostro saturatè brunneo, ad apicem albido: pedibus pallidè brunneis: iride pallidè brunneâ: plagâ nudâ anteoculari papillosâ aurantiaco-rubrâ.
Adult. Head, including the crest, cheeks, hind part and sides of neck, back, rump, thighs, and upper tail-coverts dark purplish or steel-blue with a beautiful gloss; shoulders and scapulars dull shining olive-green, the feathers of the former with burnished edges; upper wing-coverts dull olive-green, washed more or less with purplish or steel-blue, the middle ones largely tipped with white, forming a conspicuous alar bar; on the back a square patch of white (which is not always present, being probably characteristic of the breeding-season); throat, fore neck, and all the under surface of the body pure white; wing-feathers blackish brown; the secondaries washed with olive; under surface of wings dusky black; tail-feathers dull black, the two middle ones inclining to grey, and all having the shafts white at the base. Irides light brown; papillæ in front of the eyes and bare skin at the base of lower mandible orange-red; bill dark brown, whitish at the tips; legs and feet pale brown. Total length 26 inches; wing, from flexure, 10·75; tail 5; bill, along the ridge 2·25, along the edge of lower mandible 3; tarsus 2·25; longest toe and claw 4·25.
Young. There is a specimen in the Otago Museum obtained from the Chatham Islands (marked ♂) which is apparently in an immature state; dorsal patch broken and mixed with brown; alar bar much narrower than in the adult bird and likewise intermixed with brown feathers, the white ones appearing to be new plumage; general gloss on the upper parts less pronounced; lower back and rump glossed with steel-blue, instead of green as in the adult; there is likewise a blue gloss intermixed with the green on the head and hind neck. There are some old and dingy brown feathers on the mantle, from which it may be inferred that the plumage described above exhibits a change from a still more youthful state.
Obs. The above description and the accompanying figure are taken from a fine male bird obtained by Mr. Henry Travers at the Chatham Islands in August 1871. The colours of the soft parts were carefully noted by him while the specimen was fresh.
Under the head of Phalacrocorax imperialis, King, Dr. Sclater writes (‘Voyage of Challenger,’ Zool. vol. ii. Birds, p. 121):—“This Cormorant, which has been usually united to Phalacrocorax carunculatus page 154 of New Zealand, appears to be quite distinct. It has a broad white patch on the middle of the back in the adult plumage, no crest, and the white extending over the cheeks up to the naked skin round the eye. It has a broad white bar on the upper wing-coverts.” He then gives a coloured figure of the bird which he takes to be Phalacrocorax imperialis, and formulates the following synopsis of the group:—
|a. Dorsi postici fascia alba: crista nulla||1. imperialis.|
|b. Dorsi fascia nulla:|
|a′. Crista nulla||2. verrucosus.|
|b′. Cristati Gula tota nuda||3. albiventris.|
|Gulæ linea media plumosa||4. carunculatus.|
I am sorry to differ from so expert an ornithologist, but I cannot follow Dr. Sclater in this identification. He makes the absence of a crest and the presence of the dorsal patch of white the distinguishing characters of Phalacrocorax imperialis, but on turning to Captain King’s original description (l, c.) I find that his bird is a crested one. His description is as follows:—
Phal. capite cristato, collo posteriori, corporeque suprà intensè purpureis: alis scapularibusque viridi-atris: remigibus rectricibusque duodecim fusco-atris: corpore subtùs, fasciâ alarum, maculâque dorsi medii sericeo-albis: rostro nigro: pedibus flavescentibus.
From this it is evident that the ‘Challenger’ specimen figured and described by Sclater is not the bird to which King gave the name of imperialis, unless we suppose that it sometimes acquires a crest; but Dr. Sclater himself calls it, by way of distinction, the uncrested form. Nor does the formula b fit P. carunculatus, which, as I shall show when treating of that species, is never crested, whilst it does exhibit, in the breeding-plumage, the patch of white on the back. It is perfectly clear also that the crested Chatham-Island form, of which I have given a figure, is distinct from the uncrested P. carunculatus. It cannot be P. cirrhatus of Gmelin, because his bird is larger than P. carunculatus, whilst this is decidedly smaller.
After a careful investigation of the subject, and a comparison of all the specimens within my reach, I have decided to treat the crested bird from the Chatham Islands as the true Phalacrocorax imperialis, and the uncrested New-Zealand form as Gmelin’s P. carunculatus. It would perhaps be safer to give to this form a new distinctive title; but I am unwilling to add another name to the already somewhat tangled synonymy of this species and its allies. I am aware that it is “a long cry” from the Straits of Magellan to the Chatham Islands; but experience teaches us that it is impossible to lay down any strict geographical rules of distribution for birds of this class. As a case in point, I may mention an occurrence reported to me by Sir James Hector:—“When 100 miles off the Horn, a specimen of the White-throated Shag (Phalacrocorax brevirostris) flew on board our ship”!
Even in the countries which these birds inhabit their distribution is often very eccentric and unaccountable. Take, for example, P. punctatus, a species which is extremely common on the coast of the South Island, but is rarely met with north of Cook’s Strait. Mr. Adams, late taxidermist to the Auckland Museum, informed me that he found a colony of these birds on the coast near Waiheke and shot six of them. To my great surprise I saw one in the Taupo Lake in March 1877; in July 1883 I saw a flight of six in the Hauraki Gulf; and in January 1886 I found a solitary pair breeding in the midst of hundreds of the Pied Shag on some pohutukawa trees on the Rurima rocks, in the Bay of Plenty. Referring to the same species, Mr. T. W. Kirk says (Ibis, 1888, p. 44):—“I was lately informed by Mr. J. C. M’Lean that a colony of fifteen or sixteen of these birds has for more than five years been established on a reef inside Cape Kidnappers. The latter gentleman states that he has collected the eggs, but never found more than two in a nest. In December 1885 there were five nests (composed of seaweed), placed at equal distances apart, along the ledge which runs on one side of the rock about three feet from the top.”