A History of the Birds of New Zealand.
Sterna Frontalis — (White-Fronted Tern.)
Sterna frontalis, Gray, Voy. Ereb. and Terr., Birds, p. 19 (1844).
Sterna albifrons, Peale, U. S. Expl. Exped., Birds, p. 279 (1848).
Sterna atripes, Ellman, Zool. 1861, p. 7473.
Sterna longipennis, Finsch, J. f. O. 1867, p. 339.
Native name.—Tara; “Sea-Swallow” of the colonists.
Ad. ptil. æstiv. suprà albicanti-cinereus, remigibus cano lavatis, primarii primi pogonio externo nigro, pennis minoribus ad apicem latè albis, reliquis intùs versùs apicem albis: caudâ albâ: capite et nuchâ nigris, fronte et facie laterali albis: subtùs albus: rostro nigro, ad basin brunnescente: pedibus rufescenti-brunneis: iride nigrâ.
Ad. ptil. heim. similis ptilosi æstivæ, sed fronte albâ latiore et vertice plus minusve albo vario.
Juv. capite cinerascenti-nigro, albido vario: suprà dilutè cinereus, obscurè-nigricante fasciatus et notatus: tectricibus alarum minimis nigricantibus.
Adult in summer. Crown of the head and nape black; a band immediately over the bill, the lores, and cheeks pure white; back and upper surface of wings pale ashy grey; the rest of the plumage pure white; the breast and sides of the body often suffused with a delicate rosy tint, which fades after death. Irides and bill black; legs and feet reddish brown. Length 16 inches; extent of wings 33; wing, from flexure, 11; tail 7 (the middle feather 3 inches shorter); bill, along the ridge 1·6, along the edge of lower mandible 2·25; bare tibia ·4; tarsus ·6; middle toe and claw 1·1.
Adult in winter. Differs in having the white frontal band more extended, and the black crown mope or less varied or spotted with white.
Young. Forehead, crown of the head, and nape greyish black, obscurely spotted or mottled with white; the whole of the back, the feathers composing the mantle, and some of the larger wing-coverts dark silvery grey, varied with white, and handsomely mottled and barred with dusky or greyish black; the smaller wing-coverts uniform greyish black, except along the edge of the wing, where they become white; underparts silky white, as in the adult. The barred character is most conspicuous on the scapulars and long inner secondaries; and both these and the tail-feather have crescent-shaped markings near the tips.
Nestling. Covered with buffy-white down, tinged with fulvous on the head and neck, and mottled with grey on the back.
Fledgling. Feathers of the back and the scapulars greyish white, with broad crescentic marks of black; wing-coverts prettily variegated with black; the down on the back buffy white, mottled and marbled with dark grey; wing-feathers (half an inch in length) silvery grey, broadly margined with white.
Obs. I have noticed in a bird so young that it was unable to fly the same roseate tint mentioned in the description of the adult.
Some years ago, when exploring among the shoals and sand-banks of the great Kaipara heads or basin, I observed thousands of these birds; and in this wild and unfrequented part of the coast they were so fearless that they coursed about our boat within a few feet of our heads, and the discharge of a gun among them only tended to increase their apparent interest in us.
This species of Tern breeds in large colonies, as many as 200 or more being sometimes associated together. My son Percy observed in December a vast crowd of them on a small rocky island near the Taranaki Sugar Loaves. This is a favourite breeding-ground, and the birds were so closely packed that from the deck of the steamer they presented the appearance of a fall of snow. On one occasion the crew of the ‘Hinemoa’ landed at this place, and collected several bucketsful of the eggs.
On the small island of Motiti I found a large community of them occupying one end of it, and the Red-billed Gull the other, the two nesting-places being as far apart as possible. On the high intervening ground Larus dominicanus had established a breeding-place, as already mentioned.
On its nesting-ground being invaded this Tern shows fight in a very determined manner, coming in a bee-line for the intruder’s face, till within about a couple of feet, and then darting off at a sharp angle with a snapping cry of remonstrance. Captain Fairchild has known them even bolder, and has had his hat knocked off by the rapid action of their wings. By the end of February the young birds have joined the general community on the sand-banks, but they may be easily distinguished by the dark plumage of their upper surface and by their more sibilant cry. The eggs are deposited on the bare rock, often within reach of the sea-spray; and, as a rule, there are two eggs to each nest. They are usually of an elegant ovoido-conical form, measuring 1·9 inch in length by 1·3 in breadth; and they present great beauty and diversity in their colouring. The ground-tint varies from a clear greyish white to a delicate greyish green, and from a pale yellowish brown to a dark cream-colour. They are marked and spotted with purplish and dark brown in every variety of character: some have the entire surface studded with clear rounded spots, occasionally confluent; others have the marks broad and irregular; while in some examples they are spread into large dark biotches, covering a great portion of the surface. Some specimens are freckled all over with light brown, and splashed at intervals with darker brown; others have a smudged appearance, as though an attempt had been made to obliterate the markings. In the Canterbury Museum there is a curious example, having the entire surface covered with marbled veins of dark brown; and another (collected by Mr. Fuller on the Waimakariri beach) is of a delicate pinkish-brown tint, with a broad zone of confluent spots towards the larger end, and numerous scattered specks of a rich reddish-brown colour.