Part 49

CHARADRIUS HIATICULA Linnaeus

RINGED PLOVER

Contributed by Francis Charles Robert Jourdain

HABITS

The ringed plover breeds both on the east and west coasts of Greenland, ranging north to Sabine and Clavering Islands and Denmark Harbor on the east side and to Inglefield Gulf on the west. It is also said to breed near Cumberland Sound in Baffin Land, but this may refer to the semipalmated plover, Charadrius semipalmatus, and it has occurred casually in Barbados, Chile, and southern Alaska.

The subdivision of the ringed plover into geographical races is attended with considerable difficulties owing to the presence of passing migrants on many of its breeding grounds. The Siberian form, Charadrius hiaticula tundrae is generally recognized, but is only distinguishable with certainty in summer plumage. Probably the Alaskan specimen belongs to this race. E. Lehn Schiöler, with fine series of carefully sexed birds before him, separates the Greenland breeding birds from the typical race under the name of Ch. hiaticula septentrionalis, but material with accurate data is too scarce in other collections to enable us to hazard an opinion.

Spring.--In northeast Greenland, where Manniche found this species breeding plentifully, the birds arrived about the end of May or the beginning of June, at the same time as the other waders. Icelandic birds arrive early: April 22 to 28 (Faber).

Dr. W. Elmer Ekblaw says in his notes:

The ringed plover is one of the most noticeable birds of the shorelands of northwest Greenland. Few beaches are unoccupied by these noisy little birds, and rarely is one out of sound of their shrill piping. They are quite as common about the streams and pools of the interior and along the seepage swales of the ground moraines. They come to the land as early as May 29 and stay until the last week in July. Almost invariably they are mated when they arrive and only rarely does one see more than a pair together, except where they congregate about swales or shallow pools to feed. They are sociably inclined and do not hesitate to make their nests near the Eskimo villages, probably feeling more secure from Arctic foxes when near dogs and human habitation.

Courtship.--The courtship of this species has been well described by Farren, Selous, and Stanford. The former (1910) says:

Ringed plovers may be seen in pairs skimming low over the ground, circling to a far height and descending again like a flash, almost touching the ground as they do so. They do not follow each other, but each describes similar evolutions, overlapping and crossing the other’s line of flight. Their long pointed wings, showing much white, give a fictitious impression of size and as they alight on the ground after skimming a short distance with curved drooping wings they seem suddenly to vanish from sight as they touch ground; in place of the long-winged graceful flyer is a little plump-shaped gray bird, very difficult to see as it runs with short quick steps over the sand.

Edmund Selous (1901) also describes a male as advancing toward the hen a few steps at a time, and moving his legs with a rapid vibratory motion during the pauses. Stanford (1927) remarks that the courtship is by no means easy to observe even with the aid of a powerful glass.

In one party on the beach on March 20, where at least two males were contending for one female, the males ran backward and forward with short, quick steps, and when another male was near the feathers of the back and the tips of the closed wings were elevated, the tall depressed and spread out to its full extent to show the white tips of the feathers, and the whole body arched with the head and neck drawn in, the black gorget being puffed out to nearly twice its normal size. In this crouching attitude the males ran aimlessly to and fro for half an hour at a time, but making no real attempt to attack each other.

Another male--

kept running in front of the hen and sinking down on the beach every few yards exactly as if settling down on a nest. Occasionally while brooding in this way he would tilt himself forward onto his breast with the closed wing tips pointing up almost vertically over his back, the tail depressed, and the legs scratching out sand and stones behind him. The indifference displayed by the hen to this performance was as noticeable as it usually is in the case of lapwings’ “rolling” on the ground. On several other occasions in April I saw cock ringed plovers settle down and appear to brood for several minutes exactly as if they were on a nest; in one case the bird kept turning round and round on one spot, and twice at least this action was followed by an attempt at coition.

The love flight often covers nearly a mile of ground, and both birds take part--crossing and recrossing with their bodies twisting from side to side and soft beats of the wings. The double note, according to Stanford, has a remarkably vibrant quality at these times and the throat appears to be swelled out.

Nesting.--Both nesting sites and the nests themselves of this species vary considerably. The commonest site is among the sand and shingle above high-water mark on the seashore. In some cases the eggs are laid in a hollow scratched in the sand with no lining of any kind, in others small fragments of cockle shells and small stones are collected and imbedded, while other nests are more or less substantially built, from a few dead bents carelessly arranged to well-made cups in which almost any material available is utilized, such as driftwood, rabbits’ droppings, stems of leaves, and shore plants, etc. On some beaches where there is no sand the eggs may be found lying on the bare pebbles, while on the north Norfolk coast they are often placed under shelter of sea heath, and nests have been met with in cornfields, several miles from the sea, or on open grassland in sewage farms inland.

Eggs.--Normally four in number, occasionally three on late layings, while instances of five are rare. In color they vary from stone color to ocherous or clay yellow sometimes with a warm tinge, spotted as a rule rather sparingly with brownish black. Occasionally varieties with large blotches of sepia are met with and white eggs have been recorded as well as bluish eggs, without markings. The shell is deep green when viewed from within. The measurements of 100 British eggs, made by the writer, averaged 35.9 by 25.9 millimeters; the eggs showing the four extremes measure =39= by 26.5, 37 by =28.5=, =32.2= by 25 and 32.7 by =24= millimeters. Eggs from Iceland and other northern localities are decidedly smaller.

Young.--Incubation is shared by both sexes which relieve one another at short intervals and the period is variously estimated at from 22 to 25 days; probably 24 or 25 days represents the average. The young are hatched within 24 hours and leave the nest as soon as the down is dry. Apparently a second brood is reared in some cases, but many of the late nests may be second or third layings.

Doctor Ekblaw writes:

The old birds were wildly agitated whenever I approached, and by the customary simulation of injury attempted to lead me away from the nest. The fledglings ran about as soon as hatched, and like all little shorebirds were quick to respond to a warning signal and sink into pebble-like immobility. The weather was so cold that the old birds did not leave the young, for when the brood was separated both parents sheltered some of the little ones.

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

Food.--Insects, including Coleoptera (Apion, Aphodius, Haliplus, Hydroporus, etc.), Crustacea, especially the smaller species (Gammaridae, Amphipoda, etc.), Mollusca, chiefly small marine univalves, such as Littorina, Annelida (earthworms), and vegetable matter (seeds of Polygonum, etc.).

Behavior.--This is an attractive and inoffensive species, sociable in its habits and met with in flocks of considerable size out of the breeding season, when their simultaneous maneuvers on the wing are a very characteristic feature of the great estuaries, the flocks appearing to change from light to dark as the upper or under surfaces are exposed. They may also be seen on the mud flats, making short runs at intervals, when the movements of the legs and feet are so rapid that the eye can not follow them.

Voice.--John T. Nichols contributes the following:

A rather clear, not very loud, low-pitched whistle, given on the ground as much as in the air, rather infrequent. This may be written kruip or puik, occasionally distinctly two syllabled and suggesting the semipalmated plover’s call, but lower pitched. It was heard in late September from several birds loosely associated with a larger number of scattered dunlin on tidal sands north of Liverpool. They usually took wing in silence, and the species seems to be a rather silent one as seen here and elsewhere on British shores in September. They were very likely not traveling, and their voice therefore not comparable with that of the semipalmated on home shores. Also the note described is very likely not analogous with the full, loud-flight note of the transient semipalmated plover.

Enemies.--During the autumn and winter months the flocks are occasionally harried by a migrating merlin (Falco columbarius aesalon), and some clutches of eggs are annually destroyed by marauding Corvidae (crows) and Laridae (gulls). On some parts of the coast which are much exposed, great damage is done by exceptionally high tides, as many nests are built close to the high-water mark.

Fall.--In Greenland Manniche (1910) observed that the old birds left in pairs about the first week in August, as soon as the young were grown up. The young birds immediately went to the shores and estuaries, consorting with young sanderlings and turnstones and leaving for the south early in September. At the Westmann Isles in south Iceland they leave between September 20 and October 10.