The cinnamon juvenal plumage begins to appear on the flanks at an early stage and its development is rapid. Before the end of July the young bird is fully fledged and able to fly. The fresh juvenal plumage is much like that of the adult in winter; but the throat and the sides of the head and neck are plain cinnamon without dusky streaks; the feathers of the back and scapulars are more broadly edged or notched, with brighter cinnamon; the greater and median wing coverts are much more broadly bordered with or more extensively cinnamon; the greater coverts are almost clear cinnamon, with very few dusky markings; and the tail is more broadly barred with dusky.
Apparently only a very limited amount of molt takes place during the first year. I have seen birds in juvenal or first winter plumage in November, January, and May, though the last two may be exceptional cases. Perhaps some young birds assume the adult plumage at the first prenuptial molt, but certainly not later than the first postnuptial. More material is necessary to settle this point.
Adults have a complete postnuptial molt beginning in July and lasting well into the fall. This produces the winter plumage in which the breast is immaculate cinnamon and there is little, if any, barring on the flanks. At the prenuptial molt in February and March the body plumage, or most of it, and the tail are molted.
Food.—Doctor Roberts (1919) says of the feeding habits of the marbled godwit:
With their long, up-curved bills they probe the shallow water of sloughs and lake shores for aquatic insects and mollusks and also spend much of their time on meadows and low-lying prairies, where they devour grasshoppers and other insects of many kinds. These big birds, when they were as abundant as they once were, must have been an important factor in keeping in check the dangerous insect hordes of our State. But they, with others of their kind, are gone and man is left to fight conditions as he must with agencies of his own devising, less efficient, perhaps, than those provided by nature.
Audubon (1840) says: "While feeding on the banks, it appears to search for food between and under the oysters with singular care, at times pushing the bill sidewise into the soft mud beneath the shells." The sand beaches of California are favorite feeding grounds, where I have seen it associated with the long-billed curlew. I was interested to see with what dexterity these long-billed birds could pick up a small mollusk and swallow it; I could plainly see the small object gradually travel up the long bill and into the mouth of the bird. Other observers have recorded in the food of this godwit snails, crustaceans, insects and their larvae, worms, and leeches.
Behavior.—The flight of the marbled godwit is strong, rather swift and direct; the head is usually drawn in somewhat, the bill pointed straight forward, and the feet stretched out behind. Audubon (1840) says: "When flying to a considerable distance, or migrating, they usually proceed in extended lines, presenting an irregular front, which rarely preserves its continuity for any length of time, but undulates and breaks as the birds advance." Mrs. Florence M. Bailey (1916) writes:
In flight they often made a close flock, calling queep, queep, queep, queep, queep, affording a beautiful sight as the light struck them and warmed up the cinnamon wings that make such a good recognition mark. They soared down handsomely, showing the cinnamon, and as they alighted held their wings straight over their backs for a moment, the black shoulder straps showing in strong contrast to the warm cinnamon.
Though the flocks were generally most amicable, occasionally one or two of their number would get to scrapping. Two got hold of each other's bills one day and held on, one or both crying lustily. In a group another day two came to blows, first just opening their bills at each other and talking argumentatively. Later one of them made passes at the other till the harried bird lifted his wings as if meditating escape, and finally when a pass was made at his long unprotected legs, flew away. When one was teased by a companion it often cried complainingly, go-way, go-way, go-way, go-way.
It was amusing to watch the birds feed. As a wave rolled up, combed over and broke, the white foam would chase them in, and as they ran before it, if it came on too fast, they would pick themselves up, open their wings till the cinnamon showed, and scoot in like excited children. But the instant the water began to recede they would right about face and trot back with it, splashing it up so that you could see it glisten. As they went their long bills—in the low afternoon sun strikingly coral red except for the black tip—were shoved ahead of them, feeding along through the wet sand, the light glinting from them; and if anything good was discovered deeper, the hunters would stop to probe, sometimes plunging the bill in up to the hilt, on rare occasions when the tidbit proved out of reach, actually crowding their heads down into the sand.
Like all of the shore birds, the marbled godwit is exceedingly demonstrative on its breeding grounds, flying out to meet the intruder as soon as he appears, making fully as much fuss at a distance from its nest as near it, and giving no clue as to its exact location. The cries of one pair of birds often attract others, and I have seen as many as eighteen birds flying about at one time in an especially favorable locality. It shows no signs of fear at such times, often alighting on the ground within ten or fifteen yards, standing for an instant with its beautifully marbled wings poised above it, a perfect picture of parental solicitude. Even while they were feeding on the shores of the lakes we could frequently walk up to within a few yards of them.