Part 20

The juvenal plumage comes in first on the mantle and wings, then on the flanks, breast, and crown, and lastly on the neck, rump, and tail. The upper parts are “light brownish olive,” more grayish on the sides of the neck and chest; the scapulars and upper tail coverts have a subterminal sepia bar and are tipped with pale buff or creamy white; the lesser and median wing coverts are conspicuously barred with pale buff and sepia; the chin, throat, and under parts are white.

During the fall, beginning late in August, or in September, some of the body plumage, tail and some tertials and wing coverts are molted, producing the first winter plumage. This postjuvenal molt is very limited and very variable; I have seen birds in juvenal plumage as late as December 3. The first winter plumage is like the adult winter, except for the retained juvenal wing coverts. It is worn until March or April. The wings are molted during the winter at any time from October to April; and during March and April the body plumage is molted, producing the first nuptial plumage. This is like the adult nuptial, but there is more gray on the sides of the neck and less spotting on the breast, sometimes very little of the latter. But the plumage is practically adult, except for a few retained juvenal wing coverts.

Adults have a complete postnuptial molt beginning with the body plumage in August, or earlier, and ending with the molt of the primaries at any time from October to April. In winter plumage the upper parts are plain “dark grayish olive,” shading off lighter on the sides of the head and neck; the under parts are white, faintly washed with grayish on the throat. The partial prenuptial molt, involving only the body plumage comes in March and April and produces the spotted breast of the nuptial plumage.]

Food.--At the seacoast the spotted sandpiper searches for its food both on the beach and on the muddy borders of creeks and inlets, wading into the water, however, less frequently than most sandpipers; inland it feeds along the margins of sandy ponds, sluggish meadow streams and rushing mountain torrents; in farming country it strays into the meadows, fields, and market gardens and finds in all these situations food which it picks up from the low vegetation or from the ground.

Like some of the other sandpipers, however, and like several other birds which have the agility to do so, it easily captures flying insects even when they are on the wing. In order to come within striking distance of an insect before it flies away, the spotted sandpiper resorts to a ruse by which its approaching head and beak are concealed or made inconspicuous. As the bird walks over windrows of seaweed and such places where flies abound, it stretches its body out with the bill pointing straight in front, the whole bird lengthened into a line with the long axis parallel to the ground. In this position the head, from the flies’ point of view is masked by the body as a background and the bird is enabled to come so near that it can snap up a fly, even after it has taken wing, by a straight forward movement of the head. In stalking a flying prey the spotted sandpiper creeps up to the fly, moving slowly with cat-like steps, the tail motionless, and apparently never adopts the well-known trick of the semipalmated sandpiper, the running about with the hind part of the body tilted far upward, advancing upon a fly under cover of this as a screen.

A complete list of the insects which form the spotted sandpiper’s diet, could one be compiled, would doubtless be a very long one, comprising as it would both marine and land insects. The wide range of the bird’s choice of food is shown by the following quotations which prove definitely that it is a very beneficial species to the agriculturalist.

E. H. Forbush (1925), speaking of the bird’s habit of frequenting cultivated fields, says:

They feed largely on locusts, grasshoppers and caterpillars, such as cutworms, cabbage worms and army worms, also beetles, grubs and other pests of cultivated lands.

H. K. Job (1911) writes:

The usual food of most species of this class [shore birds] is aquatic insect life of all sorts. This is in part the diet of the spotted sandpiper. But as it is also a bird of field and pasture, its range of insect food is very wide, including grasshoppers and locusts. Probably almost anything in the insect line is grist for its hopper, and it is a most useful bird.

Austin H. Clark (1905a) furnishes the following unusual observation:

While on the island of St. Vincent, West Indies, last October, I observed a number of our shore birds feeding on the young of a small fish known as the “tri tri” (Sicydium plumieri), which were at that time ascending the Richmond River, near which I was staying, by thousands. The land about the lower reaches of this river was laid completely bare by the recent eruptions of the Soufrière, and in its present state proves very attractive to all the species of shore birds which visit the island during the migrations. Those observed or proved by dissection to be eating the young tri tri (which were at that time from half an inch to an inch and a quarter long) were * * * solitary sandpipers (Helodromas solitarius), and spotted sandpipers (Actitis macularia). All but the last two kept near the mouth of the river, or on the flat lands along its lower reaches; the solitary sandpiper followed the stream up into what were formerly arrowroot fields, half or three-quarters of a mile from the sea, and the spotted sandpiper was found well into the mountain forests.

W. H. Bergtold (1926) cites an instance of the bird’s catching another swift-moving fish. He says that the caretakers at the Wigwam Fishing Club, Colorado, “reported the spotted sandpiper as also catching trout fry.”

The following quotation adds crickets to the list of insects; H. W. Jewell (1909) writes:

While sitting on the banks of Sandy River one night I was attracted to the actions of a spotted sandpiper. There were lots of crickets on the shore of the river, and the sandpiper would catch one in its bill, run up to the water, and immerse the insect several times, then swallow it. This seemed a very interesting performance to me, and I wondered if all living insects caught are thus treated before they are eaten. The cricket is quite a large insect, and as this bird ate 10 or 12 he did not go to bed hungry that night.

Alexander Wetmore (1916), who examined the contents of nine stomachs, says: “Though mole crickets (Scapteriscus didactylos) were found in but two stomachs, they form 10.78 per cent of the total food.” Summarizing his findings, he concludes, “From the foregoing the spotted sandpiper is a beneficial species and should not be molested.”

Behavior.--Nothing is more characteristic of the spotted sandpiper than its flight. When it first starts from the shore the wings seem to vibrate like a taut wire; then, as the bird gains headway, they set and, depressed and quivering, they carry the bird slowly onward, often swaying from side to side, close to the surface of the water. As a rule, when startled, the sandpiper takes a semicircular course and alights a short distance farther up the beach, and if followed either takes another flight onward or doubles back as a kingfisher would do under similar circumstances. This scaling flight, somewhat after the manner of a meadow lark, is seen most commonly during the summer, but on infrequent occasions the sandpiper lets go his wings and carries them back with a long, free sweep and speeds through the air with the rapidity of a swallow. The transition from one kind of flight to the other is remarkable to see; with outstretched neck it drives along with regular wing beats, a long, slender, unfamiliar-looking wader.

J. T. Nichols mentions in his notes this peculiar flight; he says:

One might be familiar with the bird for years and believe it [the scaling flight] invariable. Careful attention in late summer and fall, however, will demonstrate that it is not. When, as rarely happens, the spotted sandpiper rises to some height to make a considerable aerial passage (especially over a stretch of marsh) the flight becomes regular like that of a miniature yellowlegs, or swift and darting as it sometimes is with a white-rumped sandpiper for instance. It also, at times, flies low over the tops of the marsh grass in this last named manner. To identify such birds in the air is very difficult, and they will pass for some one of the other sandpipers of rather small size if one does not chance to appreciate the slenderer neck and somewhat different shape, or the more uniform color of the upper parts.

The ability to swim and dive which is so noticeable in the young of the spotted sandpiper is even more remarkably evident in the behavior of the adult bird. Of the many instances recorded in the literature, the following will illustrate this well developed proclivity.

E. H. Forbush (1912) speaks thus of the action of a wounded bird:

In September, 1876, I saw a wounded bird of this species when pursued, dive into deep water from the shore of the Charles River and fly off under water, using its wings somewhat as a bird would use them in the air. All its plumage was covered with bubbles of air, which caught the light until the bird appeared as if studded with sparkling gems as it sped away into the depths of the dark river.

Later (1925) he adds a record of the bird actually running along the bottom while entirely submerged. The spotted sandpiper--

can dive from the surface of the water or from full flight, at need. Under water it progresses by using its wings which it spreads quite widely, and in shallow water it can go to the bottom and run a short distance with head held low and tail raised like an ouzel or dipper.

G. M. Sutton (1925) describes the behavior of two birds which he startled by a close sudden approach. In the first quotation he shows that the spotted sandpiper readily dives while on the wing and continues its flight under water and in the second quotation he shows the bird’s ability to rise directly into the air from beneath the water, a feat impossible for many water birds.

When the bird first flushed, its wings were fully spread, and it was headed for the open water of the lake. Upon seeing me towering above it, however, it turned its course abruptly downward, and without the slightest hesitation flew straight into the water. With wings fully outspread and legs kicking it made its way rather slowly along the sandy bottom, until it was about 8 feet out, in water over 3 feet deep. I pursued the bird, thinking at the time, strangely enough, that it was wounded. When I reached for it, it tried to go farther but apparently could not. Bubbles of air came from its mouth, and air bubbles were plainly seen clinging to the plumage of its back. At the time it was captured its mouth, eyes, and wings were all open, under water, and it remained at the bottom seemingly without difficulty. As it lay in my hands above water it seemed tired for a second or two, and then, without warning, shook itself a little, leaped into the air, and with loud, clear whistles, circled off a few inches above the water to a distant point of land.

On a subsequent occasion, May 7, 1925, Mr. Sutton--

purposely came upon a spotted sandpiper suddenly and witnessed it employ almost the identical tactics in making an effective escape. At this time, however, the bird dove into running water, swam with wings and feet rapidly moving for about 20 feet, and emerged down stream, still flying, and made off in its characteristic way, only a few inches above the water.