A History of the Birds of New Zealand.
Puffinus Gavia. — (Forster’s Shearwater.)
Procellaria gavia, Forst. Descr. Anim. p. 148 (1844).
ÆSTRELATA, gavia, Coues, Proc. Phil. Acad. 1866, p. 154.
Puffinus assimilis, Hutton, Trans. N.-Z. Inst. vol. i. p. 161 (1868, nec Gould).
Native name.—Pakahaa: “Rainbird” of the colonists.
Ad. suprà nitidè brunnescenti-niger: facie laterali et corpore subtùs toto albis: rostro sordidè plumbeo, mandibulâ pallidiore: pedibus flavicanti-albis, extùs nigro limbatis: iride nigrâ.
Adult male. Crown of the head, nape, and all the upper surface, including the wings and tail, glossy brownish black, fading away gradually towards the under surface; sides of the face, throat, fore neck, and all the under surface white. Irides brownish black; bill dark grey, lighter and sometimes yellowish grey on the under mandible; tarsi and toes pinkish flesh-colour, stained with blackish brown along the front of the tarsus, and on the outer edges of the toes; webs darker. Total length 14·5 inches; extent of wings 27·5; wing, from flexure, 8·5; tail 3; bill, along the ridge 1·4, along the edge of lower mandible 1·75; tarsus 1·5; middle toe and claw 2.
Female. Upper parts dull yellowish brown, with dingy tips; underparts white; on the sides of the neck the dark colour fades imperceptibly away. Total length 14·5 inches; wing, from flexure, 8·5; tail 3; bill, along the ridge 1·25; tarsus 1·5.
Another example (in the Otago Museum) is somewhat smaller and has the plumage of the upper parts darker.
Young. The young bird assumes the colours of the adult from the nest, but with rather paler margins to the wing-coverts, the woolly covering clinging longest to the back and flanks.
Nestling. Covered with very thick slate-coloured down on the upper, and white on the under, surface.
Obs. In this Petrel the white on the femoral region is very conspicuous when the bird is on the wing.
One from Selwyn (in the Canterbury Museum) has the upper parts sooty grey, and the underparts pure white, the former colour extending forwards from the shoulders and being nearly confluent on the lower fore neck. Another (marked ♀) from Chicken Island is somewhat smaller in all its proportions, and has the plumage of the upper parts sooty black, there is less white on the cheeks, and the dark colour is not spread forward on the fore neck.
This species of Petrel, which enjoys a wide oceanic range, is comparatively common in the seas surrounding New Zealand; and after stormy weather it is frequently picked up, either dead or in an exhausted state, among the sea-drift on the open strand. It is certainly not the same as P. opisthomelas, Coues, as I formerly supposed, for the latter species may be at once distinguished by its “fuliginous-black under tail-coverts” (see Proc. Nat. Sc. Phil. 1864, p. 139)*. Mr. Salvin has shown page 237 me a careful drawing by Keulemans from the type of P. opisthomelas (obtained off the coast of Lower California), which was sent over from the Smithsonian Institution for the purpose of being figured in his forthcoming ‘Monograph,’ and this feature is very distinct.
They congregate in flocks, often of considerable size, and fly in a compact body, generally in a zigzag course, with a very rapid movement of the wings and not far above the water. Their flight is peculiar, too, in this respect, that they appear all to turn at the same moment, like a company of soldiers, showing first the dark plumage of the upper surface and then the white underparts as they simultaneously dip towards the water.
Their habits are sociable, and flocks may often be seen in the daytime disporting themselves in the sea, making short flights just above the surface, then flopping into the water, splashing and chasing one another in their playful gambols, and when tired of their fun rising in a body and rapidly disappearing from view in the manner already described. On one occasion I saw a flock of several hundred thus amusing themselves in the broad sunshine (although the bird is more nocturnal than diurnal) as our ship was steaming through the narrow “French pass” in Cook’s Strait.
They seem to scatter at night, for as darkness approached I have noticed numerous single examples, as if the flocks of the daytime were dispersing over the surface of the ocean in quest of their food. They fly low but swiftly, and utter a note resembling the native name by which the bird is called, but somewhat prolonged, as paka-ha-a—paka-ha-a. During the breeding-season I have seen very large flocks of them between Whale Island and the mainland, some of them hovering on the wing, hundreds together in “schools” or flocks, and others scattered far and wide over the surface, floating in a listless manner as if resting after the hunting exploits of the night.
Occasionally, perhaps once in several years, they appear in prodigious flocks and seem to cover the sea for miles around; but they soon scatter again over “ocean’s boundless bosom,” and are then not more plentiful than the other Petrels. This periodical “mustering of the clans” is doubtless due to a superabundance of some particular food-supply in the part of the sea where they congregate.
Whale Island is one of their favourite breeding-grounds, the places selected being the stony, scrub-covered slopes near the summit, as well as the holes and crevices among the rocks far above high-water mark. The adjacent little island of Motoki is also a nesting-ground. The island of Karewa in the Bay of Plenty, and the numerous islands in the Hauraki Gulf are also favourite breeding-grounds. They nest in communities and their burrows are like rabbit-warrens, covering acres in extent. As a rule, they go down vertically for about a foot and then spread off laterally for a distance of two feet or more, thus forming a chamber in which the Petrel deposits her single egg and afterwards cradles her young. In the early morning the old birds go off to sea, and do not return to their nests till after dark, when there is great noise and excitement among the nestlings in their eagerness for the food which has been stewing for them all day long in their parents’ crops.
The Maoris state that the young birds quit their nests for the sea towards the end of February, which would accord with my observations on Whale Island. They do their best, however, to interfere with this domestic arrangement, for when the fledglings are about to take their departure, they are visited by Maori hunting-parties, who capture sometimes four or five hundred of them in a day, and pot them in their own fat as huahua, which is esteemed a great delicacy. Having regard to the profit the island is strictly tapu during the early part of the breeding-season, and no native is allowed to land there. The expiation of the tapu and the slaughter of the innocents form one and the same event!
It breeds on several of the larger islands in the Hauraki Gulf; and Mr. Cheeseman found it nesting on the “Hen and Chickens.”
An egg of this species in my son’s collection is broadly oval, measuring 2·3 inches in length by 2 in breadth, and is perfectly white.
* Mr. Salvin writes (Ibis, 1888, p. 356):—“Sir Walter Buller’s collection contains a specimen referred to this species, which is the first I have seen answering to Forster’s description. It has a general resemblance to P. opisthomelas, Coues, as regards the colour of its plumage, but may at once be distinguished by its pure white under tail-coverts.”