A History of the Birds of New Zealand.
Prion Vittatus. — (Broad-Billed Dove Petrel.)
(Broad-Billed Dove Petrel.)
Broad-billed Petrel, Lath. Gen. Syn. iii. pt. 2, p. 414 (1785).
Procellaria vittata, Gm. Syst. Nat. i. p. 560 (1788, ex Lath.).
Procellaria forsteri, Lath. Ind. Orn. ii. p. 827 (1790).
Prion vittatus, Lacép. Mém. de l’Inst. 1800, p. 514.
Pachyptila vittata, Illiger, Prodr. p. 275 (1811).
Procellaria latirostris, Bonn. et Vieill. Enc. Méth. i. p. 81 (1823).
Pachyptila forsteri, Swains. Classif. of B. ii. p. 374 (1837).
Prion australis, Potts, Ibis, 1873, p. 85.
Ad. similis P. banksii, sed saturatior: pileo et facie laterali nigricanti-cinereis: tectricibus alarum brunneo lavatis: staturâ majore et rostro conspicuè latiore facilè distinguendus.
Adult. Similar to P. banksii, but darker, the crown of the head, the sides of the face, and the ear-coverts being blackish grey, and the wing-coverts shaded with brown: distinguished by its larger size and much broader bill. Irides brownish black; bill blue-black on the upper mandible, greyish blue on the lower, and on the bare membrane between the crura; legs and feet pale blue. Total length 12·5 inches; extent of wings 26; wing, from flexure, 8·25; tail 3·5; bill, following the curvature of upper mandible 1·5, greatest width at the base ·8, from gape to extremity of lower mandible 1·7; tarsus 1·2; middle toe and claw 1·6.
Although closely resembling the preceding species in the colours of the plumage, this Prion may be readily distinguished by the peculiar form of its bill, which is much dilated at the base, and very conspicuously pectinated along the edges.
As already stated in treating of Prion turtur, after boisterous weather in July I found the sea-beach between Waikanae and Manawatu strewn with the dead bodies of Prion turtur and P. banksii, the former species predominating. Having occasion to make the journey again after stormy weather in the early part of the following month, I found the strand strewn with even a larger number of bodies, but, strange to say, nearly all belonging to the very broad-billed species, Prion vittatus. Out of twenty-four specimens picked up in succession, there were only three of Prion turtur and none of P. banksii. Scores of others which I was able to determine from the box-seat of the coach belonged to P. vittatus, with here and there a P. turtur, but not a single example could I find of the intermediate form so plentiful a month before. It may be inferred from this singular fact that the species do not intermingle, but fly in separate communities. I have observed flocks of Prion turtur on the wing together numbering many hundreds. Prion vittatus and P. banksii in like manner, no doubt, keep to themselves, for it is evident that the flocks in the vicinity of our coast, when caught in the fatal storm on the occasion I have referred to, were composed almost exclusively of Prion vittatus.
I opened a large number of these birds for the purpose of ascertaining on what they had been feeding. As might have been expected with storm-tossed fugitives, the stomachs of many were quite empty. In others there was a black mass of comminuted matter, and in two or three of them I detected among this matter what appeared to be the beaks of a very minute cephalopod.
Two eggs of this species, collected by Macgillivray on the island of St. Paul, in the Indian Ocean, are pure white, and measure 2 inches in length by 1·5 in breadth.