Search:

LIFE HISTORY

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 Inca Dove - the common name and sub-species reflect the nomenclature in use at the time the description was written.


INCA DOVE
SCARDAFELLA INCA INCA (Lesson)

HABITS

CONTRIBUTED by CHARLES WENDELL TOWNSEND

The charming little Inca dove, sometimes called the scaly dove, or the long-tailed dove, after characteristic features, is a bird of Tropical and Lower Sonoran Zones and occurs in the United States only in Arizona, New Mexico. and Texas. Formerly confined in southern Texas to the region between San Antonio and the Rio Grande, these doves, according to A. E. Schutze (1904), on account of long droughts, have "moved north and eastward to a country where they found food and water in abundance." According to G. F. Simmons (1925), the first record of this dove for Austin, Tex., was in 1889, while, by 1909, they had become common nesters in that region. 'Wherever found, it is resident, although in Texas, according to the same author, "a few birds move southward in colder, winter weather." Appearing to delight in human companionship, the Inca dove is rarely found at a distance from towns or the neighborhood of houses.

Courtship: Frank Stephens (1885) says of the courtship: "I saw a little group on the ground, the males strutting around the females, carrying their tails nearly vertical and cooing." Although the Inca dove may be heard cooing in every month in the year, the cooing is most in evidence during the courtship season. At this time, also, the dove is very pugnacious, and the rivalry is intense among them.

M. F. Gihnan (1911) says:

The Inca dove could never have inspired the term "dove of peace," as they are pugnacious to a fault and fight like little fiends. Two of them will face each other with one wing on guard, held straight above the body, then close In and mix it, buffeting with wings till the sound of the blows Is audible at a distance of fifty yards. The bill is also used with bloody results about the head. I have been told that one will sometimes kill the other, but never saw such an extreme case. When arranging for a fight the combatants utter a sort of growl, if It may he so described; a very guttural, anger-expressing sound.

Bryant (1891), quoting A. J. Grayson, says, "They exhibit the most ardent attachment for their mates and may often be seen caressing each other in a loving manner."

Nesting: The Inca dove delights to nest near houses or barns even in villages and towns. Indeed, nests are rarely found except in the vicinity of mankind, and this familiarity is shown by the fact, according to M. F. Gilman (1911), that "the birds are generally quite tame on the nest, rarely flying off till the intruder comes closer than arm's length," and, he adds, "they are so accustomed to human presence that the broken-wing subterfuge is rarely resorted to." A curious instance of this familiarity with man and his works is given by George F. Simmons (1925), who reported that "a nest was on a trolley wire at a switch in the eastern part of Austin, where about every seven minutes street-cars raised it from six to twelve inches above its normal position."

The usual location of the nest is on a horizontal fork or flattened limb of a tree or in a bush, and it is generally within 10 or 12 feet of the ground, varying in height from 4 to 25 feet. Shade trees planted about dwellings are commonly used. Umbrella trees, cottonwoods, elms, sycamores, fruit trees, mesquites, live oaks, acacias, thorn bushes, prickly-ash, and even Opuntia cactuses are all used for this purpose, and, according to A. J. Grayson, quoted by W. E. Bryant (1891)," not infrequently they construct a nest under the sheds of the houses, if a suitable beam is found."

A. J. Van Rossem, in his notes from Salvador, says:

Inca doves breed the year round, nor does there appear to be any notable increase or decline of this activity correlated with season. The number of broods raised per year is not known to us, but because of the activity of the species as a whole It is not difficult to conjecture four or five. There Is no cessation of nesting because of the fall molt. Males and females alike appear to have no dormant period whatsoever. This statement Is based upon specimens taken every month in the year besides others inadvertently shot but not preserved, and observations of numerous nests. Eggs were seen In July, August, September, October, November, February, and April. Nests of the usual slight dove construction were seen In orange trees, balanced on palm fronds, in mimosa thickets, and even in hanging fern baskets around the corridor of an occupied ranch house. Some attempt at concealment was usually noticeable, hut this was frequently offset by the unsecretive manner in which the parents left or approached the nest. Two eggs were the invariable rule.

According to Bendire (1892), who quotes Herbert Brown, "the nests are as a rule much better constructed than those of the Mexican ground dove. The cavity is about half an inch deep, and the materials used, fine dead twigs, are much more compactly put together than in the nests of the latter." Simmons (1925), describes the nest construction as follows:

Small, rather compact, firmly matted, almost flat platform or shallow saucer of weed stems, tiny twigs, dried grass, rootlets, a few straws, grass seed stems, bits of Indian tobacco weed, and sometimes hits of Bermuda grass, Spanish and bull moss, mesquite leaves, and a few feathers from the birds; occasionally nests contain string, horse-hair, or strips of cedar bark. Commonly unlined; rarely lined with grass stems, Spanish moss or a few small Inca dove feathers.

Simmons has frequently found Inca doves using the nests of their own species, of the western mourning dove, and of the western mockingbird, after being slightly repaired and relined. Gilman (1911) found two nests each of which was built on top of an old nest of a cactus wren.

The dimensions of the nests, according to Simmons (1925), vary from 1.8 to 3.4 by 3.6 inches, with a height of 1.15 inches and an inside depth of 0.5 inch. He speaks of one nest "about the size of a silver dollar." Bendire (1892) describes a nest he found in a thick mesquite bush as "a slight platform of twigs and grasses about 5 inches in diameter."

Eggs: [Author's note: The Inca dove lays almost invariably two eggs. These are elliptical oval, smooth with very little gloss, and pure white. The measurements of 34 eggs average 22.3 by 16.8 millimeters; the eggs showing the four extremes measure 24.3 by 16.8, 22.9 by 18, 20 by 16, and 21.8 by 15.2 millimeters.]

Young: The duration of incubation is not known. It is probably not far from two weeks, the same as the incubation period of the Mexican ground dove. Two broods are generally raised in a season, sometimes three, and occasionally four. R. XV. Quillin and R. Holleman (1918) record a case of a pair rearing four broods in one season in the same yard. Gilman (1911) says: "The past season I noted four cases where two broods were raised in the same nest, and two cases where a last year's nest was relined and used." F. C. Willard observed one pair that laid five sets of e~s; he collected three sets and allowed the pair to raise two broods. Others may have been raised later, as he was away after June 1.

Plumages: The following observations on plumage changes under artificial conditions are of great interest and possible significance, and are therefore recorded here. William Beebe (1907) subjected with other birds some Inca doves to a warm, superhumid atmosphere and found that the plumage, with each succeeding molt, became darker and developed iridescence. He says:

When the concentration of melanin has reached a certain stage, a change in color occurs, from dull dark brown or black to a brilliant Iridescent bronze or green. This iridescence reaches its highest development on the wing coverts and inner secondaries, where, in many genera of tropical and subtropical doves, iridescence most often occurs.

In other words, by subjecting the Inca dove, which belongs in a genus of tropical origin, to the humidity of the Tropics, it reverted back in the lifetime of the individual to an ancestral type. This is certainly a most surprising result and the experiment should be repeated. Mr. Beebe's skins of Inca doves showing these remarkable changes arc on exhibition in the park of the New York Zoological Society.

[Author's note: I have never seen the nestling of this dove. A small young bird, about two-thirds grown, in juvenal plumage is much like the adult; it is more heavily barred with black or dusky on the breast and flanks, with more buffy color on the belly; the feathers of the back, scapulars, and wing coverts have a heavier terminal black bar and a subterminal band of "cinnamon-buff."

A. J. Van Rossem tells me that the postjuvenal molt occurs soon after the young bird attains its full size; and that the complete postnuptial molt of adults comes at any time between July and October, inclusive, with individual variation.] Food: Weeds abound in back yards and near dwelling houses and barns, and in eating the seeds of these plants Inca doves give good service. They also eat wheat and other small waste grains that have fallen, but they are apparently unable to manage whole Indian corn. Their familiarity permits them to mingle with poultry and partake of their food.

Water is, of course, an essential part of their diet, and reference has already been made to the extension of their range in times of drought in order that they may obtain water. M. F. Gilman (1911) says: "They are rather dainty in their drinking, rarely using the chickens' drinking vessel but perching on the hydrant and catching the drops of water as they leak from the pipe. To do this they nearly have to stand on their heads, but that does not bother them at all."

Behavior: In summer these birds may be seen singly or in pairs, or rarely in family groups, but in fall and winter they gather in small flocks, which sometimes number as many as 50 individuals.

I shall always remember my first sight of this charming little dove. I was sitting alone in a small park in Tucson, Ariz., at Christmastime when 15 of these birds appeared and walked about within a few feet of me, picking at seeds on the ground. When they stooped over for this purpose, their breasts nearly touched the earth, because their legs were so short. As they walked their long tails generally sloped gently downward so as barely to skim the ground, but at times the tails were cocked up nearly vertically. When disturbed by a passer-by, they flew up rapidly into the tree overhead, their wings making a twittering sound. In the tree they sat in pairs or threes, affectionately snuggled together like love birds, their heads sunk in their breasts, their tails pointing straight down. They went to sleep at once. This was at 4 p. in.; at 4.20 they awoke and dropped to the ground to feed again.

G. F. Breninger (1897) writes:

The strange way In which Inca doves go to roost at night has recently come to my notice. Nearly a month ago, when the air at night was still chilly, I saw seven of these little doves perched on a limb side by side. This in itself was not strange, hut directly upon the backs of the first row sat three more doves. At another time I saw five In the lower row and two on top. An examination of the ground beneath showed it to be a resort to which these birds gathered to spend the cold nights of the winter months.

F. C. Willard writes of watching an Inca dove in a grape arbor in a walled-in garden in Tombstone, Ariz., when four others alighted on the same lattice bar:

The newcomer at the far end immediately began to assert herself by sidling up to her next door neighbor and striking it with her wing. She soon forced him to fly and In like manner went down the line forcing each of them to seek another perch. Having thus made room for herself, she crouched as if content to call It a day and take a nap.

They are not all love birds!

The following account of the dove's behavior is by M. F. Gilman (1911)

The vivacious little Inca dove Is the cream of the dove family, and Is in the public eye or ear most of the time. Whether sitting on a barbed wire fence or on a clothes line, with long tail hanging down perfectly plumb, or marching around In a combative manner with tail erect at right angles to the body, or rushing around busily and hurriedly, not to say greedily, feeding with the chickens in the back yard, it shows a decided Individuality and arouses interest and affection.

The faint twittering sound of the wings sometimes heard in flight has already been mentioned, but as a rule the flight is noiseless. It is a quick and jerky flight.

Voice: Simmons (1925) describes the voice thus: Monotonous, tiresome, extremely mournful, rather short two-syllabled, hard little coo, quite different from the soft, soothing manner of the western mourning dove, a slowly uttered coe-coo or co-o-o-a coo-o-o, the first slightly shorter, high-pitched, coarser, and with a as in go; the second lower, with a typical 00 SOUN, as in moon.

Myron H. and Jane Bishop Swenk (1928) give the coos in musical notation, and they describe them as follows:

The call of the Inca dove is a monotonous, unvaried, rather plaintive coo-Gocoo or whoo-oo-wltoo, rapidly repeated over and over. There is a blowing quality to it. We heard the call all through the winter, but it became louder and more insistent as the nesting season approached in March and April. It Is very different from the soft, drawled coo-oo-coo, coo-coo, coo of the mourning dove.

During the very hot months of July and August the monotonous repetition from morning to night of the Inca's coo is much disliked by those with overwrought nerves.

I have quoted under Courts/tip M. F. Gilman's (1911) description of the "growl" of the fighting birds, and he adds that "in animated talk, gossip perhaps, they excitedly utter sounds like cut-cut-ca-dooca-doo. In all quite a vocabulary is at their command."

Field marks: The chief field marks of the Inca dove are the long tail with its white edges and the scaled appearance of the feathers oyer much of the body, which is due to the darker outline of their edges. By these two marks the Inca dove may be distinguished at once from the Mexican ground dove that occurs in the same region. Half of the Inca's length is in the tail. The chestnut-brown of the wing coverts, which is concealed or nearly concealed when the wings are closed, is prominent in flight.

DISTRIBUTION
Range: Southwestern United States and Central America; nonmigratory.

The range of the Inca dove extends north to Arizona (Wickenburg, Rice, and Safford); New Mexico (Silver City); and southern Texas (Kerrville, Austin, and Columbus). East to Texas (Columbus and Santa Maria) ; Tamaulipas (San Fernando de Presas, Ciudad Victoria, and Tampico) ; northern Guatemala (Lake Peten) ; Honduras (San Pedro); and Nicaragua (Chinandega). South to Nicaragua (Chinandega); Salvador (La Libertad); western Guatemala (Duenas); Oaxaca (Tehuantepec); Jalisco (Guadalajara); and southern Sinaloa (Escuinapa, Presidio, and Mazatlan). West to Sinaloa (Mazatlan); Durango (Rio Sestin); Sonora (Opodepe); and Arizona (Tubac, Tucson, Sacaton, Phoenix, and Wickenhurg).

Casual records: Although repeatedly listed as a bird of Lower California, there are apparently only two records. Dr. Witmer Stone (1905) reported seeing "a very few in the upper Hardy River region" of the Colorado River delta, in February and March, 1905, and there is a specimen in the British Museum taken at La Paz.

Egg dates: Arizona: 37 records, February 28 to October 21; 19 records, April 15 to May 25. Mexico: 42 records, March 11 to October 14; 21 records, March 23 to April 21. Texas: 12 records, April 10 to August 10; 6 records, April 19 to May 28.

Why do birds stand on one leg?

The professor has the answer!