Chapter C: A. Bobbins (1919) describes further the behavior of the young birds

thus:

Of course it frequently happens that there is no time for
concealment. Then the young birds attempt to escape by
running, the tiny legs working with surprising rapidity and
carrying them over the ground so swiftly and smoothly that
they looked like balls of down blowing before the wind.
Also, if their escape up the beach is cut off and they
continue to be closely pressed, they do not hesitate to
take to the water. Even those only a few hours out of the
shell swim well and navigate their frail craft, if not with
intelligence, at least in a direction away from the source
of danger.

_Plumages._--[AUTHOR’S NOTE: The downy young piping plover is sand colored above. The crown, back, wings, rump, and thighs are variegated with “cream buff,” “cartridge buff,” and grayish white, sprinkled or peppered with browns; on the wings the color deepens almost to “chamois.” The forehead is buffy white; there is a more or less distinct V-shaped mark of dark brown in the center of the crown and a circle of small brownish tips around the edge of it. The wings and thighs are marked with brown spots. A white collar encircles the hind neck, and the entire under parts are white. The juvenal plumage appears first on the scapulars and sides of the breast, then on the remaining underparts, back, and crown; the last parts to become feathered are the throat, belly, and rump; then the wing quills appear, and lastly the tail. In fresh juvenal plumage the feathers of the crown and mantle are “drab gray” or “smoke gray,” broadly tipped with “pinkish buff,” giving a decidedly pinkish tone at first; but these pink tips soon fade and wear away, leaving a dull-gray crown and mantle, faintly mottled with pale tints of buffy and dusky. The black bands on the forehead and neck are entirely lacking.

The first winter plumage is acquired by a limited body molt early in the fall and by wear and fading of much of the plumage that is retained. It is like the adult winter except for the worn and faded edgings on what juvenal feathers are retained, mainly wing coverts and scapulars. A partial prenuptial molt early in the spring produces a nuptial plumage which is practically adult.

Adults have a complete molt in late summer and fall--August to October--and a partial prenuptial molt in late winter and spring, mainly in March. In winter plumage the crown and mantle are “pale ecru drab,” without the pale edgings, with no black frontal band, and with a restricted brownish instead of black collar. The black frontal band and the black collar, characteristic of the nuptial plumage, are usually acquired in March; the extent of the black collar increases with age and the complete collar probably indicates an old bird.]

_Food._--Arthur H. Howell (1924) says: “The food of this plover, as indicated by the contents of four stomachs secured in Alabama, consists principally of marine worms, fly larvae, and beetles.” E. H. Forbush (1925) lists the following: “Insects, crustaceans, mollusks, and other small marine animals and their eggs.”

The feeding habits of the piping plover as it hunts for food along our beaches are characteristic. In marked contrast to the nervous haste of the sanderling and the rapid darting about with lightning-like thrusts of the bill of the smallest sandpipers, the behavior of the plover is leisurely, and as they pick up food from the sand the movements of the head are deliberate. Three or four may sweep down the beach together, close to the sand, but when they alight, after a moment of stillness, they separate, each bird running a little way, isolating itself from its companions (another point of difference from the sanderling, etc., which in migration tend to keep close in a flock while feeding). Generally they begin at once to hunt for food. They run a short distance, then pause and stare at the sand with neck a little outstretched, head tilted a bit to one side, perhaps looking for a movement to show where food is, for often, leaning farther forward, they pick something from the sand. As they run over the beach--a run and a pause, another run and another scrutinizing pause, often changing direction to catch up a bit of food--the birds suggest very strongly a robin feeding on a lawn and the resemblance is strengthened when the plover seizes a 3-inch-long worm and drags it from beneath the sand, pulling slowly and carefully lest it break, and swallows it whole.

_Behavior._--Their actions while feeding are apparently identical with those of the semipalmated plover, and the flight of the two birds is similar if not exactly the same. Their flight is wilder than that of the sanderling, for example, which drives steadily along; they twist and turn more often and tilt from one side to the other, giving the impression of extreme swiftness and agility.

Descriptions of the action of the sitting bird when disturbed differ very little. The bird is invariably wary and steals off before the intruder comes near, leaving him in doubt as to the existence of a nest. After the eggs are hatched, however, their actions change completely, and the parents display the utmost concern for the safety of their young. In the following quotation from his notes, E. H. Forbush describes graphically this behavior, and also shows that even in the early days of the young bird’s life the parents do not feed them. Mr. Forbush says:

A colony of piping plovers on the same beach had been much
reduced in numbers but the behavior of one pair showed
that they had young on the beach. We saw one plover and
then another fluttering along the ground like young or
crippled birds. Their actions might deceive a novice, but
by watching them with a glass, we soon saw that they were
adult birds. They threw themselves on the ground, breast
downward, and, drooping the flight feathers or primaries,
raised and agitated the shorter secondaries, until the
motion resembled the fluttering pinions of young or wounded
birds, meantime pushing themselves along over the sand
with their feet. As the wings were not spread, the long
primary quills were not noticeable, and so the imitation
of the struggles of a helpless bird was almost perfect.
Immediately we began a careful search for the nest, looking
in all the usual hiding places in or under the tufts of
beach grass, but no nest could we find. As the old birds
continued their plaintive cries and circled about, we
extended our search, expecting to find some half-grown
young flattened out somewhere on the beach. Finally, by
hunting over the sand we found on the open beach, a nest
exactly like that of the least tern. A few little pebbles
had been grouped in a slight hollow, and there, partly
beside and partly on the pebbles, lay three lovely little
downy chicks and one egg. We attempted to photograph the
parents, but they would not come to the young; and, as the
little ones had already begun to run, about, we sunk an old
barrel in the beach, and put them and the egg in it, that
we might know where to find them on the morrow.

The day was foggy and cold, and during the night a
thunderstorm drenched the earth; but the next morning the
egg had disappeared, and four lively youngsters were
running around in our barrel. They were now so active, that
if one were liberated it would be rather difficult to catch
it, while if hidden, it would be almost impossible to find
it.

We kept them there two days, until we made sure that the
parents never fed them. They brooded them quite constantly,
but brought no food whatever, and we made certain that the
young were able and willing to find their own food within
24 hours after they were out of the shell. It was seen that
unless they were liberated from the barrel they would soon
starve to death.