This is another species whose claim to a place in the American list rests on its occurrence in Greenland, but, rather curiously, all the occurrences are recorded from the west coast and not from the east side, as might have been expected. Herbert Winge, in 1898, was able to record six specimens obtained at various localities between 1844 and 1898, as well as one reported in the autumn of 1893. As it is a breeding species in Iceland, its occurrence in Greenland from time to time may well be expected.

Courtship.—As the oyster catcher is an extremely striking bird, with its strongly contrasted plumage of black and white, red bill, and flesh-colored feet, and is also by no means scarce and very noisy, its breeding habits challenge attention, and a good deal has been recorded on the subject by Edmund Selous, Seton Gordon, William Farren, and others. It is on the whole a sociable species, and one peculiar characteristic is that in the middle of the breeding season it is not unusual to find three birds together, either resting or in flight, without any open signs of hostility. According to Selous, these associations are often composed of two males and one female, and as he observed them together not only in the early part of the pairing time but also late in the season, it would seem that, except perhaps just in the height of sexual activity, the social instinct is predominant. The following account is taken from William Farren’s (1910) description of the “Piping parties”:

The piping of the males depends on the presence of the female. Another male in the neighborhood hears the note, becomes interested, pipes a little, and then flies direct to where the performance is taking place. He places himself by the side of the other male and the two pipe together to the female. Generally unresponsive, the female may walk away, when she is followed by the two males, who continue their serenade. In one instance observed by Mr. Selous, the female flew down to a lower shelf of rock and the two males piped down to her from above; and when at last she flew away they, with a few single querulous notes, assumed their ordinary attitude and walked disconsolately about. The flight of the female always ended the performance.

Mr. Selous (1901), in describing the piping serenade of the male, states that when he begins he faces her, but “having once begun he seems more enthralled by his own music than by her and will turn from side to side or even right round and away from her, as though in the rhythmical sway of his piping.” This remarkable song is audible a long way off and is described well by Selous as “an earpiercing clamor.” He writes it as “kee kee kee kee kervee kervee kervee kervee kervee” becoming fainter in its later stages and ending in a long-drawn out quavering trill. In some cases, according to Selous, the female also pipes, and one pair, presumably already mated, will chase another pair, all four piping together. He also instances a case in which an unattached male approached close to where a hen was sitting; she left the nest, and, joining her mate, the two advanced on the intruder, piping a warning, and put him to flight.

Perhaps the fullest study of the subject is contained in a paper by J. S. Huxley and F. A. Montague (1925). Here the piping is described thus:

Any number of birds, from one to seven or eight or possibly more, may take part in it. Typically, what occurs is as follows: One or more birds begin the loud characteristic piping which typically again is given in a special attitude, the head and bill directed straight downward, the bill held open and very slightly vibrated, the neck thrust forward so that the shoulders show up with rather a horsey look. Sometimes, but not always, the whole body is bobbed up and down at intervals in the way common to so many wading birds, but not very markedly. Frequently, but again not always, the performers trot rapidly round when piping, very often close side by side and usually in a serpentine course, with short quick steps. Sometimes one of the performers will suddenly turn right round through 180° in the middle of its performance; one I saw turn through the complete 360° in two spasms.

Huxley and Montague have shown that this piping performance has not only a sexual significance, but that it also plays a number of other rôles in the bird’s life, as, for instance, in unilateral courtship, mutual courtship, aggression, sexual jealousy, territorial jealousy, and probably social excitement—that is, under all forms of strong emotion except fear. Details are given of observed piping by large parties, two pairs, threes (the commonest form), “twos” and “ones.”

Another courtship activity recorded in the same paper is the slow-butterflylike flight with the wing beats at about half the ordinary pace carried out by a solitary bird. Coition is apparently preceded by no preliminary ceremony whatever, the initiative coming from the male, the female standing quite still and giving no visible indication of readiness to pair. For a fuller discussion on the origin and meaning of the piping ceremony the reader is referred to the paper by Huxley and Montague (1925).

Nesting.—There is considerable variation in the nesting sites of this species. Among sand dunes it is often to be met with on the summit of a dune, a mere hollow in the sand. On shingle banks it may be among pebbles, sometimes lined with small white stones or shells, obviously brought by the bird. Other nests are placed in natural recesses of rock, on grass land, when at times quite a good-sized nest is built of any wrack or rubbish available. While in many cases the nest is placed close to the shore it is frequently found in Scotland by the sides of the rivers far inland, and on the continent, in level grassy meadows in the reclaimed marshes of Holland. Exceptionally nests have been recorded from a larch wood on an island, among bracken, etc.

Eggs.—The normal number of eggs is three, but two are also commonly found, and in some districts sets of four are not at all uncommon. Exceptionally five and six eggs have been found together. As is usually the case where three eggs are normal, they are oval rather than pyriform in shape and in color are yellowish stone or ochreous, boldly marked with spots, streaks, and scrawls of blackish brown and some ashy shell marks. There are also variations with warm rufous tinge in the ground color, or very rarely with a pale bluish ground or even pure white. Some sets are boldly blotched with sepia black. The measurements of 100 British eggs, made by the writer, average 57 by 40.07 millimeters; the eggs showing the for extremes measure 70.1 by 37.4, 62.1 by 48.9, 51.6 by 40.4, and 62.6 by 35 millimeters.

Young.—Incubation is carried on by both sexes, but probably the female takes the greater share, and she has been observed to sit for three or four hours without changing. The period is estimated at 21 days (Paynter), 23 to 24 days from finding full set (W. Evans), and 24 days (Faber). Probably the latter estimates are more correct. The young when hatched remain a day or two in the nest and are attended by their parents for at least five weeks after hatching, according to J. M. Dewar (1908). R. H. Brown, however, estimates it as about 29 days.

Plumages.—The plumages and molts are fully described in A Practical Handbook of British Birds edited by H. F. Witherby (1920).

Food.—Chiefly marine mollusca; univalves, such as limpets (Patella), small whelks (Buccinium) and periwinkles (Litorina) and bivalves, including mussels (Mytilus edulis), cockles (Cardium), etc. Also annelida, earthworms, and sandworms; crustacea (shrimp, etc.), and insects, including Coleoptera, Diptera and their larvae (especially Tipulidae), Lepidoptera (larvae and pupae of Noctuidae); occasionally Holothurians and some vegetable matter (grass seeds, grains, etc.).

Behavior.—The feeding habits of the oyster catcher have been exhaustively studied by J. M. Dewar, who has given the results of his investigations in a paper in the Zoologist for 1908. Careful examination of the shells of mussels showed that about 78 per cent were opened by means of a stab from the bill through the dorsal border. As in their normal position this is the exposed portion this is perhaps natural, but only those which have the valves slightly opened are vulnerable and the weakest point in the shell is on the ventral border, which is rarely exposed. The best feeding time is when the scalps are first exposed by the ebb, before the mussels have closed their shells and again when the tide is rising and the shells are just beginning to open again. When the tide is up the birds rest in long lines, head to wind. The flight of the oyster catcher is peculiar and characteristic, the wings being rapidly moved within a very short arc, so that they seem to be vibrated at the tips.

Enemies.—The oyster catcher has few natural enemies, though no doubt occasionally a nest is destroyed by Corvidae (hooded crows and carrion crows or rooks).

Fall.—The Misses Rintoul and Baxter have observed a tendency to the renewal of spring display during the autumn months. The Shetland birds move southward in September and do not return until March.

Winter.—During the winter months the oyster catcher is generally to be met with in flocks, easily recognized by their striking coloration and characteristic notes. The wild ringing sound of their calls, a clear kle-eep, coming from hundreds of throats at once, is, as T. A. Coward remarks, as delightful as it is harmonious.

DISTRIBUTION

Breeding range.—Iceland, the Faroes, the British Isles, and the coasts of northern Europe from northwest Spain and Brittany to the Baltic, and along the Scandinavian coast to Archangel, probably also in the Black and Caspian Seas, south to Macedonia and Asia Minor. Replaced by allied forms in Asia and Japan.

Winter range.—Some winter in Iceland, many in the British Isles, but the main winter quarters lie in the Mediterranean, the Red Sea, the Persian Gulf, the African coast south to Mozambique, and India.

Spring migration.—At the Straits of Gibraltar the passage northward takes place in April and May, according to Farrer, and in Malta in April, but in the eastern Mediterranean it is apparently rather earlier, for in Greece one has been noted at the end of March, and Lindermeyer gives mid-April as the main passage date. At Corfu it has been seen on March 20. Danish birds arrive on their breeding grounds late in March or early in April, and in southern Sweden in March while in Finland not till late April.

Fall migration.—Gaetke noted many young birds on Heligoland in August and migrants have been recorded for Greece in mid-August. The autumn movement is more prolonged than the spring passage, owing to the presence of young as well as adults, so that at Malta birds have been recorded from August to November. The main passage at Tangier takes place in October.

Casual records.—Winge’s Greenland records include two dated April 19, 1885, near Nanortalik, and one on June 16, 1888, north of Jakobshavn. It has also been noted on Jan Mayen (A. G. Nathorst and L. C. Masters); once north of Bear Island, July 28, 1910; and once in Spitsbergen, July, 1906 (Mathey-Dupraz).

Egg dates.—From the British Islands, April 26 to June 26 (25 dates), May 2 to 29 (14 dates), June 4 to 26 (10 dates); Holland, May 11 to 25 (25 dates); Norway, June 10 to 27 (8 dates); Faroes, May 15 to 22 (3 dates).