A History of the Birds of New Zealand.
Œstrelata Affinis. — (Mottled Petrel.)
Procellaria affinis, Buller, Trans. N.-Z. Inst vol. vii. pp. 215–16 (1875)
Œstrelata gularis?, Salvin, Ibis, 1888, p. 358.
id. suprâ saturatè cinereus: dorsi plumis et supracaudalibus nigro terminatis: tectricibus alarum minimis et alâ spuriâ nigricanti-brunneis: primariis extùs nigricanti-brunneis, intùs albis: secundariis pallidè cinereis, albo angustè marginatis, basaliter albis: rectricibus saturatè cinereis, duabus externis intùs albidis: fronte albâ cinerascenti-nigro variegatâ: regione suboculari conspicuè cinerascenti-nigrâ: facie laterali guttureque albis: pectore imo et abdomine cinereis, plumis basaliter albis: corpore reliquo subtùs albo, pectoris lateribus cinereo lavatis, hypochondriis et subcaudalibus inferioribus cinereo variis et minutè transfasciatis: subalaribus albis, exterioribus conspicuè nigricantibus: rostro nigro: pedibus sordidè flavis, digito externo et membranis interdigitalibus nigris.
Adult. Crown, hind neck, and all the upper surface dark ashy grey, the feathers of the back, rump, and upper tail-coverts margined with greyish black; all the small wing-coverts and the primary quills brownish black, the latter largely marked with white on their inner webs; the secondaries and their coverts ash-grey, narrowly margined with white, and wholly white towards the base of each feather; tail-feathers dark ashgrey, the two outermost ones on each side marked with light grey on their inner webs; forehead slightly mottled with white; lores, chin, and throat perfectly white; a conspicuous spot of greyish black under each eye; upper part of breast washed and freckled with grey; middle part of breast and the abdomen dark cinereous, the underpart of the feathers white; sides of the body and smaller tail-coverts freckled and minutely barred with grey; long under tail-coverts white. The inner surface of the wings is pure white, but there is a broad bar of slaty black extending from the elbow to the carpal flexure, where it spreads and is continued along the outer edge. Total length 13 inches; wing, from flexure, 10·5; tail 4; bill, along the ridge 1·25, along the edge of lower mandible 1·5; tarsus 1·2; middle toe and claw 1·75.
I described this species from a specimen in the Canterbury Museum, to which I found attached a ticket with the following memorandum, “Shot; Potts River, 1872.” I afterwards received a freshly skinned one from Mr. C. H. Robson, with the slightest possible variation in the measurements. This was obtained at Cape Campbell; and Mr. Robson wrote to me (under date June 3) that he had secured another, which struck the Moeraki Lighthouse in thick weather and was killed. (See Plate XLV.). Still more recently a fresh example was received at the Canterbury Museum from the Spencer Mountains. This one has the colours more pronounced than in my type; but exhibits the same pretty mottled markings on the forehead, and freckled touches of grey on the sides of the neck and lower part of the breast, where the white mixes with the clear dark grey of the rest of the body.
Dr. Finsch has expressed his belief that this Petrel is the same as Procellaria mollis (Gould); but the two birds are absolutely and entirely distinct. It may possibly prove to be identical with Procellaria gularis (Peale), as suggested by Mr. Salvin; but there is no specimen of the latter in Europe with which to compare it. The unique example upon which Peale founded his description (U. S. Expl. Exp., Birds, p. 299) is in the Smithsonian Institution, and I hope to investigate the subject further during my proposed visit to America next year. In the meantime I have thought it better to figure and describe my bird under the new name which I bestowed upon it in New Zealand.