Part 45

Young.--The incubation period according to the observations of J. A. Spurrell (1917) is from 24 to 25 days; according to Ira N. Gabrielson (1922) it is 25 days. J. M. Bates (1916) found it to be 26 days and Althea E. Sherman (1916) found that 28 days elapsed between the laying of the last egg and hatching.

Both sexes incubate (F. L. Burns, 1915), and both take care of the young. Robert B. Rockwell (1912) relates the following:

“Mr. [L. J.] Hersey was fortunate enough to see one set of eggs hatch. He says the parent birds carried every bit of shell away from the nest within two hours after the hatching.” As soon as the moisture has dried from the down, the young are on their feet and leave the nest and the parents often lead them to the nearest water. They bob and call at an early age. Althea R. Sherman (1916) had watched a nest very closely from the beginning, but she says of the young: “So protective was their coloration, so adroit was parental management that they were not seen after leaving the nest until they had attained the size of adult house sparrows.” The young often escape notice by lying motionless on the ground. At such times they may sometimes be picked up without showing signs of life.

Both parents play the usual wounded-bird act to beguile the intruder from the eggs or young. The following detailed account by Ira N. Gabrielson (1922) is worth giving here:

It is impossible to approach the nest on foot without alarming one or other of the birds, as one was always on guard some distance away. At the appearance of a person walking, the one on guard would fly in a circle about the nest, giving the alarm, at the first note of which the one on the nest ran rapidly until some distance away and then took wing to join its mate in circling about the intruder. A man ploughing corn was viewed with absolute indifference by both birds, the team often passing down the row next to the nest without disturbing the sitting bird. At an alarm, however, both birds flew about the field unless the intruder persisted in approaching the nest. In such a case one of the birds dropped to the ground near the person, invariably on the side away from the nest, and fluttered about apparently in the greatest distress. The attitude most frequently assumed was as follows: one wing was held extended over the back, the other beat wildly in the dust, the tail feathers were spread and the bird lay flat on the ground, constantly giving a wild alarm note. This performance continued until the observer came very near when the bird would rise and run along the ground in a normal manner or at most with one wing dragging slightly as long as pursuit was continued. If the observer turned back toward the nest, however, these actions were immediately repeated. When the parents had succeeded in luring the intruder about 100 yards, they seemed satisfied as they then flew away.

M. P. Skinner found that when he scared one bird from the nest, the mate was apt to steal around behind him and take its place on the nest. He says that

In addition to their broken-wing tactics, both of the killdeer at times would pretend to brood anywhere on the foundation, evidently to lead me to think that that was where their nest was. * * * On one occasion I found an adult with one young about four days old. The youngster ran under the old one and into its feathers; then the old bird squatted down, covering it. Just then I saw the other bird come running and exchange with the first parent, nestling down over the youngster.

While the broken wing tactics are used by the birds for man, dogs, and other predatory animals, in order to draw them away from the eggs or young, quite different tactics are used for browsing animals that might step on them. Thus Howard Lacey (1911) noticed that a flock of driven goats divided. “I walked up to the place expecting to find a rattlesnake, and found instead a killdeer standing over her eggs with upspread wings and scolding vigorously.” Norman Criddle (1908) writes “If the danger came from a cow or horse, the tactics were changed and the birds with both wings and feathers spread out would run into the animal’s face, and so by startling it drive the intruder away.” This habit of scaring away a browsing animal probably accounts for the following experiences related by M. P. Skinner. The change to the broken-wing tactics appears to show great discernment and intelligence on the part of the bird.

Twice when riding near two different unsuspected nests, the birds got up with startled cries and faced me with their tails spread horizontally and quivering, although I was on horseback and towered high above them. After a few moments they made off with pretended broken wings, limping, falling down and fluttering.

Aretas A. Saunders (1926) observed a parent very zealous in the care of its young:

This brood of young was accompanied by a parent. They occupied a certain section of the shore of the pond, where the young hid beneath the rushes when danger approached, and ran over the mud flats at other times. The parent remained near, and drove all other birds from the vicinity. While shore birds and marsh birds were abundant all around the Mill Pond, at this point they kept away because of the parent killdeer. The parent was extremely belligerent, and I watched it attack other killdeers, yellowlegs, spotted sandpipers, soras, and song sparrows that happened to wander in the vicinity. All birds seemed glad to leave the vicinity.

Plumages.--[AUTHOR’S NOTE: The most distinctive feature of the downy young killdeer is the long, downy tail, black above and elsewhere barred with “pinkish buff” and black, with long, hair-like, buffy down below protruding beyond the rest of the tail; the forehead, chin, throat, a ring around the neck and the under parts are pure white, except for a tinge of pinkish buff in the center of the forehead; a broad, black stripe above the forehead extends around the crown to the occiput; a black stripe extends from the lores, below the eyes to the occiput; there is a broad black stripe entirely around the neck, below the white; the crown, auriculars, back and inner half of the wings are grizzled “vinaceous buff” and dusky; there is a black space in the center of the back and a black band across the wing between the grizzled inner half and the white distal half.

The juvenal plumage is similar to that of the adult, but the head markings are less distinct; the feathers of the nape are tipped with “amber brown” and those of the back, scapulars, wing coverts and tertials are more or less broadly tipped or edged with the same, more broadly on the scapulars and wing coverts and more narrowly on the upper back and tertials; the intermediate white band on the breast is always more or less suffused with brownish.

The postjuvenal molt is apparently very limited and the first winter plumage is largely the juvenal plumage modified by wear. It is much like the adult except for the worn and faded edgings of the wing coverts, and some of the scapulars and tertials and the tail, which are retained. At the first prenuptial molt, which may take place from February to June, the plumage becomes practically adult.

Adults have a complete postnuptial molt, mainly in August and September, and a partial prenuptial molt of the body plumage in early spring. Nuptial and winter plumages are practically alike.]

FOOD.--The killdeer is man’s friend. It consumes great quantities of insect pests. The most complete study of its food by examination of stomachs has been made by W. L. McAtee (1912) who sums up as follows:

“In all 97.72 per cent of the killdeer’s food is composed of insects and other animal matter. The bird preys upon many of the worst crop pests and is a valuable economic factor.” Of this large proportion he finds that beetles constitute 37.06 per cent; other insects--grasshoppers, caterpillars, ants, bugs, caddis flies, dragon flies, and two-winged flies, 39.54 per cent; other invertebrates--centipedes, spiders, ticks, oyster worms, earthworms, snails, crabs, crawfish, and other crustaceans, 21.12 per cent. The 2.28 per cent of vegetable matter is chiefly made up of weed seeds such as button weed, smart weed, foxtail grass, and nightshade. He found that various kinds of weevils were eaten such as those of alfalfa, cotton boll, clover, rice, white pine, etc. In a single stomach he counted 41 alfalfa weevils.

Harold C. Bryant (1914a), during an outbreak of grasshoppers in California, found that the contents of one stomach was 100 per cent grasshoppers, and he estimated that each killdeer averaged 33 grasshoppers daily. Arthur H. Howell (1906) has found that the killdeer is among the most important of the birds that eat the cotton-boll weevil. Samuel Aughey (1878) found 258 locusts and 190 other insects in the stomachs of nine birds taken in Nebraska. E. R. Kalmbach (1914) found in the stomach of a killdeer taken in a western alfalfa field 316 weevils; in another 383. C. W. Nash (1909) has found the stomachs of killdeers taken in orchards completely filled with weevils. E. R. Kalmbach (1914) has also found May beetles both in adult and grub form in the stomachs, wireworms, and insects that attack sugar cane, corn, carrots, grape vine, sweet potato, tobacco, and sugar beets. Caterpillars, he found to be a favorite article of diet, also grasshoppers and crickets, crane flies and their larvae. One stomach contained hundreds of larvae of the salt marsh mosquito. He adds:

The killdeer thus befriends man, but it does something also for the domestic animals, not only by eating horseflies and mosquitoes, as just mentioned, but also by preying on ticks, including the American fever or cattle tick, which has caused such enormous losses in some parts of the South.

Arthur T. Wayne (1910) says: “This species is very partial to fields which are being ploughed, and at this time they are always very tame, following each furrow as soon as it is turned over in order to secure the worms which are exposed.” I have watched a killdeer in a ploughed field swallowing a large earthworm. Several strenuous gulps were needed before the act was accomplished.

Behavior.--The interesting behavior of this bird during courtship and in the care of the eggs and young has already been detailed under the appropriate headings. In general it may be said that the killdeer has the usual plover habits when feeding of alternately running and then of standing still, as if to listen or look, always with head up, and of dabbing suddenly at the ground for its food. Like some other species of plover, it occasionally bobs or “teeters” in a nervous manner. This varies from a slight bob of the head, which is first hitched up and then brought down, to a bob combined with a tilting up and down of the whole body on the hips. In swift running they excel, and this serves them to good purpose in the pursuit of insects.

M. P. Skinner writes: “When they get out on bare ground their speed is really astonishing. I have had them run along the road ahead of my horse for quite a distance.” In plover fashion and unlike sandpipers, the killdeer in feeding does not keep in a compact flock but spreads out irregularly. John F. Ferry (1908) writes: “A curious sight was that of numbers of these birds scattered about the lawns at Leland Stanford University while the sprinklers were in operation. This recalled the robins on the lawns of the Eastern States.”

Sometimes a number fairly close together may be found crouching on the sand or gravel asleep, or they may sleep standing, often on one foot. One or more are awake, however, watching, all from time to time open their eyes and look about. Notwithstanding their striking coloration, one may walk almost to a flock under these circumstances without noticing them. The “ruptive” marks about the head and neck break the continuity of the surface and the bird is not recognized as such.

The flight of the killdeer is rapid, generally close to the ground when the bird is on the lookout for food, but at other times, especially in courtship, as stated above, the flight may be at a great height. They usually fly about singly in a wavering and erratic manner, but sometimes in considerable flocks. Widely scattered birds when startled usually unite into a compact flock and fly away together. W. L. Dawson (1923) says: “I have seen flocks of 50 killdeers bunch closely and turn in silence and disappear in perfect order.”

Whenever the killdeer is unmolested, as is the case now under protection, it becomes very tame, as is shown above in the account of the birds at Stanford University. N. S. Goss (1891) writes:

“In Coatapec, Mexico, a pair came daily to feed and dress up their feathers beside a little run or gutter in the center of the narrow paved street opposite my room in the hotel, regardless of the people on the sidewalks, only running or dodging to avoid a person crossing or to keep out of the way of a pack of mules, etc.”

Voice.--The killdeer is at times the noisiest of birds and is hated by the gunner, for its alarm cries disturb every bird within a long range. The “song” has been described under courtship. F. M. Chapman (1912) well characterizes some of its cries as “half-plaintive, half-petulant.” Kill-deé kill-deé is the common cry from which it takes its name, for it omits the r at the end. But it has a great variety of other cries with which it rends the air, and I find in my notes the following: kee-kee; eet-eet-eet; kee-ah, kee-ah; dee-dee-dee; tsee-he, tsee-he; tso-he, tso-he; ker, ker, ker, and piercing tee-ars. It is, of course difficult to express these cries properly on paper, and a great variety of syllables have been recorded by different writers.

Aretas A. Saunders (1926) gives the following excellent description: