White-tailed Kite

Published by the Smithsonian Institution between the 1920s and the 1950s, the Bent life history series of monographs provide an often colorful description of the birds of North America. Arthur Cleveland Bent was the lead author for the series. The Bent series is a great resource and often includes quotes from early American Ornithologists, including Audubon, Townsend, Wilson, Sutton and many others.

Bent Life History for the White-tailed Kite – the common name and sub-species reflect the nomenclature in use at the time the description was written.

The above name was applied to the North American bird by Bangs and Penard (1920) to distinguish it from the smaller South American race, to which the name leucurits was originally applied. The northern bird is larger, with longer wing and tail and relatively wider tail feathers. They say of the two ranges: “The small southern form ranges from Argentina and Chile, northward to Venezuela; the large northern form from California, Texas, Oklahoma, South Carolina, and Florida, southward through Mexico to British Honduras and Guatemala. There is thus a wide area in southern Central America and northern South America between the ranges of the two forms as outlined above, where the species apparently does not occur at all.”

This gentle and attractive bird seems to have become exceedingly rare, or to have been entirely extirpated, in the eastern portions of its North American range. During my six seasons, or parts of seasons, spent in various portions of Florida I have never seen this kite; once a special trip was made to a section where our guide said they had recently nested, but no sign of them was found. Donald J. Nicholson tells me that he has not seen one there since 1910. We could not find it in southern Texas, and I have no recent records of it there. In certain sections of California it seems to be holding its own, though exceedingly local in its distribution, and nowhere universally abundant. I doubt if it ever was very abundant, although Cooper (1870) referred to it as “quite abundant in the middle districts of California, remaining in large numbers during winter among the extensive tule marshes of the Sacramento and other valleys”, and Belding (1890) considered it “still a common resident” about these marshes “in the centre of the State.” But Belding quotes Dr. 13. XV. Evermaun, as calling it “a rare resident” in Ventura County, as early as 1886; and he quotes W. E. Bryant as saying that “it is still a very rare resident” in Alameda County. It seemed to be the general opinion, at that time, that the white-tailed kite was a disappearing species. As a result, it has since been rigidly protected by law and exempted from collecting permits.

Now comes more recent light on the subject, which is more encouraging. Dr. Gayle B. Pickxvell (1930) has published the results of his exhaustive study of the literature and his field work in the Santa Clara Valley. Referring to past and present conditions in that region, he says:

In spite of the fact that Taylor, in 1889, wrote of the Kite, “I venture to assert that there are not more than four pairs this year breeding within a radius of seven miles of that city I San Jose]”, today, forty-one years later, there are still that many or more. * *

Let us estimate that an average of four pairs of Kites (too high an estimate for some, too low, perhaps, for others) frequents each~ We have then sixteen pairs of Kites in this entire valley. Twenty pairs, forty birds, I feel convinced, account for every Kite from Gllroy to the Bay and from. Mount Hamilton to the summit of the Santa Cruz Mountains.

The Kite was certainly more numerous In San Joaquin and Sacramento counties forty to sixty years ago than it is now. In other regions where it was present, especially in marsh districts, undoubtedly It has been seriously reduced In numbers. The condition in hill sections inhabited by It can be but guessed at. Here it probably has suffered least. * *

This Kite is probably a dying species, never within historical times having predominated as such raptorial birds as the Desert Sparrow Hawk or Redtailed Hawk for instance.

Since the above was written Dr. Pickwell (1932) has published a “requiem” for the kites in this valley; whereas he estimated that there were possibly 16 to 20 of these kites in the Santa Clara Valley in 1928, he now says: “This day (October 30, 1931) there cannot be more than two or three, and all too possibly none.” We hope that this is a mere local condition.

His observations on the home life of these kites were made in the foothills of the Mount Hamilton Range in Santa Clara County:

The Slatore ranch lies in the foothills whose summits are grass-covered with wild oats and bromes, with scattered valley oaks and live oaks, and here and there a cluster of California coffee berry (Rhamnus catiforaica) and gnarled Sam bucus. Rocky outcrops, where more moisture may be trapped, have curious copses of scrubby growths of toyon, holly-leaved cherry, sages and sage brush; and the gullies lined with buckeye, California laurel, and poison oak run down to Silver Creek where the laurels and willows predominate. But the hills are mostly smooth as velvet, golden velvet most of the year, and green oaks are scattered over the velvet, like buttons on a buxom vest. In three buttons on this velvet vest were occupied nests of the White-tailed Kite.

That such a habitat is not an unusual Kite home is shown by the fact that all the Kites of Santa Clara Valley today are, excepting one or two pairs, restricted to the lower foothills of the Mount Hamilton Range and Santa Cruz Mountains, on either side of the north end of the Valley. The exception is of not more than two pairs that occur to the north of San Jose between that city and the Alviso salt marshes. These frequent the cottonwoods and eucalyptus trees of the Coyote Creek and, not infrequently, are seen hunting over the treeless marshes at the~ foot of the Bay In common with Marsh Hawks, native there, and Turkey Vultures and Red-tailed Hawks from the hills.

Bendire (1892) says of their haunts: “Their usual resorts during the breeding season are the banks of streams or the fresh water marshes, especially if a few scattered live oaks or willow groves are close by, and their favorite nesting sites are the tops of live oaks, although other trees are also made use of whose foliage securely conceals the nest during incubation.”

The impression I gained from men I talked with in California and from my own limited experience there was that this kite shows a decided preference for the vicinity of water, fresh-water marshes and streams; in such places it finds its food readily available all through the year, and it probably does not wander far away even in winter. According to Audubon (1840) it was found in similar haunts in Texas and Florida.

Nesting: The white-tailed kite nests in a variety of situations. Usually the nesting pairs are widely separated, but sometimes several pairs may be located near each other in favorable situations. Two of the nests studied by Dr. Pickwell (1930) were in “valley oaks (Quercus lobata) , and t.he third a coast live oak (Quercu8 agrifolict). The three formed an oblique or scalene triangle on the rolling hills with the longcst side 320 yards and the others 200 and 175 yards respectively. To anyone conversant, with the wide spacing of most raptorial birds this juxtaposition of the Kite nest territories seems unusual: indeed, so much in contrast with their near-relatives, semicommunal.” The data, which he compiled from the literature cited, show that 11 nests were in live oaks, 3 or more in unspecified oaks, 2 or more in s camores, and 1 in a maple. The heights from the ground varied from 18 to 50 feet; another that he measured was 59 feet. The nests were made of sticks and twigs of oaks in most cases, one being made of willow twigs. They were lined with grasses, dry stubble, barley straw, weed stems, rootlets, or Spanish moss. Some were described as flat, flimsy structures, and others were large, wellmade, substantial, and deeply hollowed. Of five references that describe nesting sites, “two describe foothills (with oaks), two stream banks (or marshes with live oaks and willow groves nearby), and one a willow swamp.”

Dr. B. XV. Evermann wrote to Major Bendire that his first nest “was near the end of one of the topmost limbs of a Chester Barlow (1897), for one season at least, indulged in the bad practice of robbing the kites of their second sets. He found that they required about three weeks, or from 19 to 23 days, to lay a second set after the first set had been taken. These birds will almost always make a second attempt to raise a brood, in which they should not be discouraged, for whether they will make a third attempt or not is an open question.

I can add a little from my limited personal experience with the nesting habits of the white-tailed kit.e, as two of the three nests I saw were in situations different from any mentioned above. I was told that there were about six pairs of these kites nesting on an island in the Suisun Bay marshes. On April 15, 1929, my informant, James Moffitt, took me there to investigate it. It was a low flat island a mile or more square, mostly covered with long, thick grass, quite marshy in places, but largely dry. It was partially surrounded by a canal, which we’ navigated in a power boat. Extending along the banks of this canal in a curving line was a row of tall eucalyptus trees over a mile long. It was in these trees that the kites were nesting. As we approached we saw a kite sitting in the top of a dead tree, so we landed; and, after a short search, we saw what looked like a nest about 40 feet up in the thick top of a eucalyptus. After we had rapped the tree several times the kite flew off. It was a very uncomfortable tree to climb, but I managed to reach the nest, which was firmly lodged in the topmost crotch. I was surprised to find in it four small young, recently hatched. The nest was well made of small fine twigs, deeply hollowed, and profusely lined with dry grass; it was rather bulky and filled the crotch quite deeply. It had probably been used in previous years, as these kites have often been known to repair and use their old nests. Wishing to find a nest more conveniently located for photography, we spent considerable time hunting through the long row of eucalyptus trees; but, although we located at least three other pairs of kites, we could not find another nest. Although well hidden from below, the nests are open from above and give the birds a good lookout; the birds probably left the nests as they saw us coming.

Another nest was shown to me by M. C. Badger on April 27, 1929. It was located in an extensive tract of small willows and cottonwoods, mixed with a dense tangle of underbrush and vines, growing over many dead or fallen trees and branches, all of which covered a broad sandy plain along a river in Ventura County. The nest was not over 15 feet from the ground, yet well hidden in a thick mass of tangled vines in the top of a small dead willow. It was a well-made nest of coarse sticks and fine twigs, deeply hollowed and lined, in the bottom of the hollow only, with strips of inner bark. It measured 21 inches over all, and the inner cavity was about 7 inches in diameter; it held three eggs. One of the birds was seen in the vicinity, but it did not come near the nest. As the eggs were warm, she had probably slipped off when she heard us coming through the thick brush. Another nest (p1. 17) that ho showed me was about 30 feet up in the topmost twigs of a small willow in the middle of another extensive tract of willows, cottonwoods, and thick underbrush.

Eggs: The eggs of the white-tailed kite are among the most beautiful and richly colored of any of the hawks’ eggs; consequently they are greatly in demand among oologists. The set usually consists of four or five eggs, sometimes only three, and I have one record of six eggs. In shape they vary from ovate to oval, and the shell is smooth but not glossy. The white, or creamy-white, ground color is usually largely, and often wholly, concealed by the profuse markings of rich browns, large blotches of dark ‘~bone brown” or “liver brown”, over washes or splashes of brighter browns, such as “burnt sienna”, air~ber brown”, “hazel”, “tawny”, or “ochraceous-tawny”; some eggs are finely spotted with the darker browns over the lighter washes, or more rarely over the whitish ground color; in some eggs the heaviest markings are concentrated at one end and very rarely the rest of the egg or the entire egg is mainly white; the splashes and blotches have a longitudinal trend. The measurements of 50 eggs average 42.5 by 32.8 millimeters; the eggs showing the four extremes measure 45.3 by 33.3, 42.4 by 35.6 and 38.1 by 30 millimeters.

Young: Dr. Pickwell’s (1930) evidence “indicates that the incubation period is not less than 30 days. Young are in the nest about 30 days.” Probably both sexes incubate; the sexes are so much alike that this is difficult to determine unless the act of nest relief is seen; such an observation does not seem to have bcen made. But both parents are known to share in the care of the young and sometimes an exceptionally aggressive pair will swoop down at the intruder. Chester Barlow (1895) relates the following:

After leaving the female flew over and around me a few times and was presently joined by the male, both flying near and uttering a raspy, clacking note which I had never heard before. Tills no doubt was giving vent to their anger. Now and then the short, sharp whistle characteristic of the bird was uttered. Soon the female flew to an oak a short distance away and the male took up the battle in earnest. Soaring away perhaps 100 yards he came swiftly toward me almost on a level with my head until within about tea feet when he would switch upwards. Then he would soar up and swoop down at lightning speed, always changing his course before reaching me. The rush of his wings was plainly audible. Again he was joined by the female but after a few attacks both flew to near-by trees where they remained till I bad departed.

The young, according to Dr. Pickwell (1930), show, the usual reactions, common to all raptorial birds, when too closely approached. “At first approach the young Kite spreads wide the wings and backs off with mouth agape, emitting a rasping note Tf the tormentor persists, the bird thrusts its feet forward with a resultant dropping back upon the tail. The third and last stage is to drop completely on the back and to present the most impressive weapons a Kite has, the talons.”

Plumages: The smallest young, such as I found in the nest., are sparsely covered with short, dull-white down, tinged with “pinkish buff” on the crown and dorsal tracts. At a later downy stage Dr. Pickwell (1930) found the young bird clothed in “heavy bluish down.” A nearly full-grown juvenal is a beautiful bird; the forehead is white and the crown mostly “cinnamon~~, heavily streaked with dusky; the back and scapulars are “hair brown” to “drab-gray”, broadly edged with “cinnamon”, or white and “cinnamon”; the tail is “pale to pallid mouse gray”, with a darker subterminal band and white tips; the lesser and median wing coverts are brownish black, the latter tipped with white; the remiges are “light to pale mouse gray”, mostly white-tipped, the primaries darker near the tips; the under parts are white, heavily suffused with “cinnamon” on the breast and less so on the belly; the lores are dusky. Dr. Pickwell (1930) adds: “Toes and tarsus, yellow; beak and claws, black; eyelids, blue; iris, brown.”

This plumage is worn but a short time, and the bright colors soon disappear by wear and fading. A postjuvenal molt begins in July and continues through the fall; it involves all the contour plumage and the lesser and median wing coverts. Some November birds have nearly completed the molt but are still largely brown on the back. A January bird shows the last of this molt and is renewing the scapulars and tail feathers. Except for the wing quills, which are probably not shed until later, the young bird is practically adult by spring.

Adults apparently have a prolonged molt late in summer and in fall; a December bird has not yet complet~d the molt of the wings and tail but is otherwise in fresh plumage. I have seen South American birds molting their flight feathers in July and October, their winter and spring.

Food: The food of this kite includes field mice, wood rats, pocket gophers, ground squirrels, shrews, small birds, small snakes, lizards, frogs, grasshoppers, crickets, beetles, and other insects. Probably very few birds and few of the larger mammals are taken, but mainly the smaller vertebrates and the insects named. It is evidently a highly beneficial species. Dr. Loye Miller (1926) noted, from the examination of a well-filled stomach:

“that both its appetite and its table manners are far from dainty. Remains of four meadow mice (Microtus) and an entire shrew (Sorex oracles) were Identified In the contents of stomach and crop. The shre~v was absolutely entire. The largest mouse had been torn apart In the lower thoracic region and the hinder portion bolted entire with skin and fur In place. Two mouse heads had been swallowed hair and all. The fore quarters of the mice seemed to have been stripped of skin, but great masses of skin and fur had been swallowed after stripping them off. Viscera and small bones indicated that most of both mice had been eaten, and there is no reason to believe that any part had been discarded. Well cleaned bones from two other Microtus skulls were still retained in the stomach.

Dr. Pickwell (1930) writes:

The Kite bunts, not by soaring and searching from a lofty position as do Buteos, nor by the low harrier method of the Marsh Hawk, but by a rather erratic scouting from a position intermediate between these two. When prey Is seen the bird “stands” with wings quiet It the air is moving sufficiently to permit It to “kite”, as its name would intimate its habit to be, or beats the wings slowly from an angle well above the back. During such a stand it drops Its legs. If It stoops it makes no falcon drop of lightning ~peed with wings drawn Into a thin wedge along the sides of the body, but keeps them up in a V angle above and slips down with legs hanging and at a speed one would never guess was more than fast enough to catch a snail. But that they do catch prey, some of it very agile, there is no doubt. And that this method is used to catch it there Is no doubt either, for they have been observed to do so.

Laurence G. Peyton (1915) says: “One morning, while working near the nest, my brother saw one of the Kites returning from the direction of the river with something in its claws. ~tVhile still some distance from the nest it began calling and was quickly joined by the other bird. The first bird remained hovering in the air like a Sparrow Hawk, while the other darted up underneath it, took the food from its claws and returned to the nest while the other sailed away.”

Behavior: The flight of the white-tailed kite is light, airy, and graceful; often it is a pretty fluttering flight with quick wing beats, or a stationary hovering flight like a sparrow hawk; and at times it is quite swift. I noticed that wheii the bird is soaring or scaling there is a bend in the wing, as in the osprey. Dr. Pickwell (1930) describes it as “with wings slightly raised and down-curving at the tips.” Also he says: “The leg-dangling habit of the Kites is one of their most conspicuous oddities. On the nesting territory the protesting birds flew here and there nearly constantly, uttering their cries, beating the air slowly with short strokes, the wings held up at a sharp angle above the back, the legs dangling from a point about the center of the body.”

W. H. Hudson (1920) says of the South American form:

Its wing-power is indeed marvellous. It delights to soar, like the Martins, during a hig~a wind, and will spend hours in this sport, rising and falling alternately, and at times, seeming to abandon itself to the fury of the gale, Is blown away like thistle-down, until, suddenly recovering itself, it shoots back to Its original position. Where there are tall Lombardy poplar-trees these birds amuse themselves by perching on the topmost slender twigs, balancing themselves with outspread wings, each bird on a separate tree, until the tree-tops are swept by the wind from under them, when they often remain poised almost motionless in the air until the twigs return to their feet.

Although ordinarily gentle birds, these kites are often very pugnacious toward certain large birds, crows and hawks, that invade their territory. Several observers have seen them persistently drive away crows and the various Buteos. Dr. Pickwell (1930) writes:

In fact many of our records of Kites have coiime about because our attention has been drawn first to a large hurried Buteo In the distance and glasses showed there not only Buteo but Kites above swooping down, one, then the other (Kites are nearly always in pairs), in huge parabolas reaching a hundred feet or more above the harried giant. Down one comes with a rush and swings up again. Immediately after, the other one drops, then up, and so around and around they alternate until the distance and blue swallows up Buteo and tormentors. This game is played the year around, in the breeding season and out. Perhaps, as with the excitement that small birds display over the discovery of an owl, there may be a meaning in the Kites’ pugnacity. It nmy well be that the contents of the Kite nest, in the very top of its oak, concealed from below but completely exposed from above, are a temptation to these big hawks the Kites so persistently annoy. If so, then there is something of significance in the fact that Turkey Vultures, though they have always been, in the Kite territory, more numerous than all other large birds, are never molested.

Voice: Dr. Pickwell (1930) also gives the best description of this bird’s notes, as follows:

The notes are several in number and no one word or term describes them all. The most frequently uttered is a spasmodic short whistle: keep, k~p, k~p. At a distance it sounds like chip, chfp, chtp, or ktp, kip, ktp, ic~p, or even more chicken-like, cheep, oh~p, ch~p. This is the note that is given as the birds beat slowly here and there with legs dangling, and it expresses the mildest solicitude. Undoubtedly Dawson (1923) means this note with his “clewlc”. The next is more highly pitched and longer, a “plaintive whistle” in truth. It may be transcribed as kr~k or kr~-~k. It may be as repeatedly and rapidly uttered as the former and expresses greater solicitude. The last and most solicitous, uttered usually only when an intruder is climbing the tree to a nest, is a prolonged k~-rdk or k-~-s-~k. This note comes at the end of a series of k~p notes. Its terminus is lower and ahuost guttural, reminding me much of the whang of a focal-plane shutter. The notes of the young are two. They have a mild, high-pitched kr~d-tdk like the adults, and when at the height of their intimidation display they have a harsh scream uttered with the mouth enormously agape. This reminds one much of the rasping scream of the Barn Owl.

Field marks: The most striking field mark of this kite is its whiteness; in the distance it seems to be wholly white; it might easily be mistaken for a white domestic pigeon, except for its peculiar flight. But it can be recognized by its flight, described above, as far as its outline can be seen. If near enough its black shoulders and, at times, its dangling legs are diagnostic. As seen from below, it appears wholly white with a dark crescent at the bend of the wing and gray at the extreme tip; its tail is decidedly rounded.

Enemies: Milton S. IRay has sent me some extensive notes on his experiences with these kites in several of the central counties of California, from the late nineties up to 1932. He says that jays, magpies, or crows will sometimes puncture or destroy the eggs in an incomplete set. Once he saw a raccoon leaving a nest, and the eggs, which it had contained previously, had entirely vanished. He mentions a very loosely built nest, “so frail and open that one of the four eggs partially fell through the nest.” Another nest “was so compactly built that it held water” and, after a storm, the eggs were “almost submerged”; the nest was subsequently deserted.

He agrees with other observers as to the recent disappearance of these kites, saying: “Occasional birds were recorded in the last decade but at the present writing (1932) the birds seem to have disappeared from ahuost every point simultaneously.” As to the cause of its decline, he says:

This Kite is peculiarly friendly and unsuspicious and therefore exceptionally easy to shoot. This is particularly true during the nesting period. Through a mistaken belief that the bird preys on quail, ducks, and other game birds the kites have been widely shot by hunters, gamekeepers, and ranchers. ‘fhe ‘hunts” of gun clubs Instituted by the various cartridge companies to exterminate owls, hawks, jays, and crows (these hunts are a curse of the present generation) have been largely responsible for the extermination of these beautiful birds. In a number of cases I have actually been able to prevent the birds being shot. In some Instances I have found that the rather close resemblances this kite bears to the siimhler gulls, as Bur~aparte’s and the kittiwake, has also prevented it from being killed.

DISTRIBUTION
Range: The Southern United States south to central South America; accidental in central and northern States. Not considered migratory and now apparently almost extinct in North America.

Although the white-tailed kite is a transcontinental species, its range (in the United States) is more or less discontinuous, there being great areas from which it is practically or entirely unknown. The range extends north to central California (Geyserville, St. Helena, and Stockton); Oklahoma (Fort Arbuckle); and Florida (near Lake Kissimmee). East to Florida (near Lake Kissimmee and Fort Myers) ; eastern British Guiana (Demerara River) ; eastern Brazil (Porto Real, Bahia, and Itarare) ; and eastern Argentina (Concepcion, Baradero, and Buenos Aires). South to Argentina (Buenos Aires); and Chile (Arauco). West to Chile (Arauco and Santiago) ; northwestern Argentina (Tucuman) ; northern Brazil (Forte de San Joaquim) ; western British Guiana (Mount Rorainta); Lower California (San Carlos and Cape Colnett); and California (Alainitos, Saticoy, Santa Barbara, Hollister, San Jose, Santa Clara, Lake Merced, Nicasio, and Geyserville).

The range as outlined is for the entire species, but the United States form, F. 1. majusculus, is not known south of Lower California.

Casual records: Audubon recorded the white-tailed kite as breeding on the Santee River, S. C., but Wayne (1910) believes this to be an error. A specimen was recorded from Marthas Vineyard, Mass., on May 30, 1910; one was shot near Kenner, La., on October 11, 1890; Ridgway reported a pair seen at Mount Carmel, Ill., during the summer of 1863 or £884; one was said to have been taken near Ann Arbor, Mich., in September 1878, and one in Livingston County on April 21, 1879 (Barrows, 1912) ; while it also has been reported from northern California, as a specimen was obtained about August 6, 1924, at Miranda, and there is also a record from Red Bluff (C. H. Townsend, 1887).

Egg dates: California to Texas: 120 records, February 12 to June 21; 60 records, April 2 to 29.