Smooth-billed Ani

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 Smooth-billed Ani – the common name and sub-species reflect the nomenclature in use at the time the description was written.

This curious member of the cuckoo family is a tropical species of rare, or perhaps only casual, occurrence within the limits of the United States; a few may occur more or less regularly in southern Florida or Louisiana, but to find it in abundance one must visit the West Indies or South America. It has a variety of local names, such as black ani, black witch, blackbird, savanna blackbird, and tickbird, the last from its habit of eating the ticks that infest cattle. Charles B. Taylor sent some interesting notes on this bird to W. E. D. Scott (1892) ; regarding its haunts in Jamaica, he says:

The AM appears to be abundant in all parts of the island. It is one of the commonest birds near Kingston; and in most open and sparsely wooded lands, or in the vicinity of cultivated clearings, little groups or companies may nearly always be seen. Blackbirds are invariably present wherever cattle are pastured. I cannot recollect an instance in which I have noted a herd of cows at pasture without a flock of these birds appearing in company with them or in their immediate vicinity. This association is doubtless chiefly for the purpose of feeding on the ticks and other parasites on the animals, a good work largely shared by the Grackles (Quisealus crassirostris). it is most interesting to watch a company of Blackbirds when thus engaged. Many are perched on the backs of the cattle (two or three sometimes on one cow), others are on the ground hopping about fearlessly among the grazing herd, searching for Insects at the roots of the herbage or capturing those disturbed by the feet of the cattle.

Nesting: He says on this subject:

Their nesting habits are exceedingly curious and interesting. Many individuals (possibly members of one flock) work together in the construction of a large nest in which all the females of the company lay their eggs. The number of eggs deposited in different nests varies greatly but is of course dependent on the number of birds in a company. Six and eight eggs are commonly found. I once took eleven, and in August last year I saw a clutch of twenty-one that had been taken from a single nest! It is probable that normally Dot more than two eggs are deposited by each bird, but nothing definite can be said on this point. The nest, which is usually placed high up in a tall tree, very frequently In a clump of mistletoe on a “bastard cedar”, is a large, loosely constructed mass of twigs, entirely lined with dried leaves. But the most remarkable circumstance in connection with the nesting of these birds Is the deposition of the eggs in regular layers with leaves between. This custom I had long heard of before an opportunity offered for personal observation. In the first nest I examined, the eggs were in two distinct layers, separated by a deep bed of dry leaves ; the bottom layer consisted of four eggs and these, strange to say, were all infertile. I believe this singular habit is practised in all cases where a large number of birds resort to the same nest.

Dr. Alexander Wetmore (.1927) writes:
Although this species often builds a communal nest, ibis is not always the case. Near Cayey [Porto Rico], January 22, two anis were seen constructing a nest in a tree about thirty feet above a small stream, the male sitting on a limb above while the female was in the nest, as yet only a loose miss of sticks and weeds. She moved and turned to shape it to her body. with her long tail sticking nearly straight up In the air. Near Bayaman, July 25, a single bird slipped quietly from a bulky nest in a clump of bamboos and only its mate appeared to join it. The nests were all large and bulky and were located from six to thirty feet above the ground. Bowdish reports a communal nest found near Agnadilla, August 13, built eight feet from the ground, in a thicket of bushes and trees. This nest contained twenty egg’s, placed in layers of four or five, each layer being covered with dead leaves to separate it from the next lot of eggs above. Eight of the egg were partly incubated and twelve were fresh.

John G. Wells (1902) says: “A flat nest is first built and about 6 or 7 eggs laid in it; then these are covered over and over. Eggs laid, and so on until four or five layers of nests have been constructed one over the other.

“I have seen four of these birds sitting on the nest until the top layer of eggs is hatched, and the young fledged, it is scraped off and incubation goes on with each succeeding layer, until all the eggs are hatched.”

Eggs: On account of its communal nesting habits, the number of eggs laid by each individual ani does not seem to be known; nor is anything known about the period of incubation. The number of eggs found in a nest varies greatly, from 4 or 5 up to 20 or more, depending on the number of females laying in the nest. I have in. my collection a set of 18, there is a set of 19 in the Thayer collection, and sets of 20 and 21 are mentioned above.

The eggs vary in shape from oval to elliptical-oval. Bendire (1895) says that the eggs “are cylaucous-blue in color, and this is overlaid and hidden by a thin, chalky, white deposit; as incubation advances the eggs become more or less scratched and the blue underneath is then plainly visible in places, giving them a very peculiar appearance.” The underlying color of some of the eggs that I have seen is “pale Nile blue”; others have described them as green.

The eggs are often very much nest stained. Mr. Taylor (Scott, 1892) makes the following interesting observation regarding the scratches: “What seems very singular is that comparatively little of this chalky covering gets rubbed off the sides, where from the turning over of the eggs in the nest we should expect to see the greatest extent of denudation, whereas one or both ends are nearly always wholly denuded. * * * So cleanly and evenly is it done, and to such an extent, that I feel confident it is the work of the birds themselves, their beaks alone being able to accomplish it. At the same time it is easy to see that the marks and scratches at the sides are the result of friction with the twigs and leaves of the nest.”

The measurements of 63 eggs average 35.03 by 26.27 millimeters; the eggs showing the four extremes measure 40.4 by 28, 36.5 by 30, and 29.21 by 23.37 millimeters.

Young: Alexander F. Skutch has sent me the following notes on the development of young smooth-billed anis, as observed by him on Barr ‘ o Colorado Island, Panama: “The newly hatched ani is covered with black skin quite devoid of any trace of feathers. Its eyes are tightly closed. The development of this naked, helpless, little creature is amazingly rapid, By the second day the sheaths of the flight plumes have already begun to sprout. By the third day the eyes are open, and the sheaths of the contour feathers have begun to push out from the skin. The pinfeathers grow rapidly and become very long before they begin to release the true feathers which they enclose. When the young ani is 5 days old, the body feathers peep from the ends of their sheaths. At this age, the nestling could hang by one foot from my finger, and pull itself up by the use of its feet and bill, which was hooked over the sup port. When placed on the ground, it attempted to crawl away through the grass, and might have, succeeded in escaping if I had not watched it carefully. Returned to the nest, it would not remain in the bowl, but climbed out to perch on the rim, where it uttered a little whine.

“When I approached the nest on the following day, the 6-day-old youngster hopped out and began to climb through the thorny branches of the orange tree, but soon it lost its hold and fell to the ground. When I picked it up, it uttered a weak imitation of the parents’ usual call. The flight feathers, as well as the body feathers, were now pushing forth from their sheaths, and the latter were longer than on the preceding day. Much bare skin was, however, still visible between them. On the following morning the nest was empty; and I could not discover what had befallen the occupant.”

Plumages: The youngest bird I have seen is about half grown and fully feathered. The contour plumage is soft and short, “bone brown” on the under parts and somewhat darker above; the wings and tail are glossy, purplish black, much like those of the adult; the bill is smaller and less specialized than that of the adult. On account of the extended breeding season, it is difficult to give any definite dates for the molts. I have seen a young male, taken March 7, that was just completing the molt of the wings and tail, but the body plumage was still juvenal; from this I infer that the juvenal plumage may be worn for the whole of the first year. Maynard (1896) took some birds that had just completed molting on March 8; also some that had just begun to molt on April 24. 1 have seen young birds molting into adult plumage in December.

Food: P. H. Gosse (1847) says of the food of the ani in Jamaica:

The food of our Blackbird, though consisting mainly of insects, is not confined to them. We usually find the stomach distended with caterpillars, moths, grasshoppers, beetles, and other insects, to such a degree that we wonder how the mass could have been forced in. But I have found these contents mixed up with, and stained by the berries of the snake-withe; and in July I have found the stomach crammed with the berries of the fiddle-wood, (Cytharaxylon) which had stained the whole inner surface a bright crimson. Flocks of these birds were at that time feeding on the glowing clusters profusely ripe upon the trees. Stationary insects are the staple food; to obtain which, they hop about grassy places, and are often seen to jump, or to run eagerly at their prey; on which occasions the long tail, continuing the given motion after the body has stopped, is thrown forward in an odd manner, sometimes nearly turning the bird head over heels. * * *

One day I noticed a cow lying down, around which were four or five Blackbirds, hopping on or off her neck, and eagerly picking the insects from her body; which service seemed in no wise unpleasing to her. I have also seen them leaping up on cows when grazing; and, on another occasion, jumping to and from a horse’s back; and my lad Sam has repeatedly observed them clinging to a cow’s tail, and picking insects from it, as far down as the terminal tuft. * * *

But stationary insects are not the only prey of the Crotophaga; in December, I have seen little groups of them engaged in the evenings, leaping up from the pasture about a yard into the air, doubtless after flying insects, which they seemed to catch. * * * I have seen one with a dragon-fly in Its beak, which It had just caught, but it may have been while resting. At another time I saw that a Blackbird had actually made prey of one of our little nimble lizards (analog).

Maynard (1896) says that “anis live largely on locusts, especially large species, which is quite common on the Bahamas, and which has peculiar, rather disagreeable odor, which is imparted to the birds.” W. E. Clyde Todd (1916) says that, on the Isle of Pines, “it is fond of following in the wake of brush-fires, picking up the roasted lizards, snails, and insects.” Dr. Wetmore (1916) reports that the stomachs of 41 birds from Puerto Rico contained 91.3 percent animal matter, mostly harmful insects and arachnids, including mole crickets, other crickets, locusts, sugar-cane root-borers, leaf beetles, other beetles, squashbugs, other bugs, caterpillars, and spiders; the other 8.7 percent was vegetable matter, mostly seeds and fruits of 7 species of wild plants. He also says elsewhere (1927) : “On May 20 near Yauco three anis were seen in a tree in which several mazambiques had nests. The anis were very near these nests, and the blackbirds, together with a pair of gray kingbirds, were much excited, but appeared to be unable to drive out the intruders, It was certain that the anis were bent on robbing the nests, and one was shot in the act of gulping down something which was later found to be an egg. No other instances of this evil habit were observed.”

Behavior: Gosse (1847) writes:
Though Its usual mode of progression on the ground is by hopping, or rather bounding, the feet being lifted together, the Blackbird Is seen occasionally to run In a headlong manner for a short distance, moving the feet alternately. He Is fond of *sitting in the morning sun on a low tree with the wings expanded; remaining there perfectly still for a considerable time. In the beat of the day, in July and August, many may be seen In the lowland plains, sitting on the fences and logwood hedges with the beaks wide open, as if gasping for air; they then forget their usual loquacity and wariness. Often two or three will sit In the centre of a thick bush, overhung with a matted drapery of convolvolus, whence they utter their singular cry In a calling tone, as If they were playing at hide-and-seek, and requiring their fellows to come and find them.

Several observers have noted that anis roost at night huddled close together on a branch, like domestic fowls, and that they often bunch together in this way during a rain. Dr. Wetmore (1927) writes:

These strange birds are found in flocks that contain from half a dozen to twenty or more individuals, ranging mainly In pasture-lands, but going also Into the cane-fields and orange groves to feed. In pastures they remain near the cattle, keeping ahead of them with long hops, In order to get the Insects that the cattle scare up. Any intruder Is greeted with a querulous call, and the whole flock flies in a straggling line across the fields to perch In a bush or low tree, where they crowd together and peer out curiously, their long tails and arched beaks giving them an odd appearance. In the early morning, when the grass is wet, they frequently sit In the sun with the wings extended in order to dry them or to absorb heat. The wings are small for the size of the bird, and the flight, accomplished by a series of steady wing beats alternating with short sails, is not strong. In a heavy wind the birds are almost helpless, and they seldom rise high from the ground at any time. When on the wing, the back appears concave from the fact that the bead and tail are held on a higher level.

C. J. Maynard (1896) says:
In flight they most nearly resemble a Canada or Florida Jay, alternately flopping and sailing, moving in a straight forward flight from tree to tree with great rapidity, uttering their mournful notes as they quickly disappear in the distance. * * *

A careful study of the Anis convinced me of the fact that a number of females are led by two or three males, and these males take great care of their charges. They utter cries of alarm when they perceive an intruder, and drive the females before them into a place of safety. I have even seen males fly against females or young birds which did not attempt to escape soon enough, and knock them off the limb on which they sat and then accompany them to a distant thicket.

I am inclined to think that the Ani is polygamous and this habit of the males taking care of a Dumber of females would appear to confirm this idea.

Mr. Taylor (Scott, 1892) gives a somewhat different impression, thus:
The Blackbirds at their best have a very lean and shabby appearance, and are slow and awkward in their movements. I have watched an individual make several ineffectual attempts to alight on the frond of a cocoanut palm; but even among the branches of other trees their actions appear awkward. Their flight is slow and gliding, somewhat labored, and of little duration, the birds often appearing to fall short of the point originally aimed at. Yet they will chase the large yellow butterflies, and I was shown a large green locust that one of these birds was seen to capture in flight and afterwards drop. In the progress of a flock from place to place they do not usually fly all together, but move away In straggling groups or couples. One or more individuals first start off with their wailing call, followed soon after by two or three; after a little delay then two more go; another pause, then one, then three, and so on. If a tree has very dense foliage they alight (with much awkward scrambling) on the tops or extremities of the highest branches, where they may gain a clear and uninterrupted view, and this is usually the case when they are traversing very open country.

Voice: The note of the ani has been called a wailing or a whining whistle; it has been said to resemble the notes of the -wood duck. Dr. Wetmore (1927) says: “The ordinary call-notes are a low kur-r-rk and a querulous quee ick, quee ick, varied by low chuckling notes. When the birds are at all wild, they serve to alarm the entire country, as they begin to call on the slightest provocation.” It has also been expressed as que-yitch, que-yuch, que-yuch by Gosse (1847) and similarly by others.

Field marks: The ani is such a peculiar and unique bird that it could hardly be mistaken for anything else. It is the only long, slender, black bird, with a long tail, short wings, and a huge bill, that is to be found within its range,’so far as I know. Its shape and its manner of flight are quite different from those of the grackles; its concave back in flight, referred to above, is distinctive. Gosse (1847) says: “The appearance of the bird in its sliding flights is unusual; the body is slender, the head large, and the beak enormous; and as in flying it assumes a perfectly straight form, with the long tail in the same line, without flapping the wings, it takes the aspect, on a side view, rather of a fish than of a bird.”

Where our two small species of anis come together in Panama, they are likely to be confused, but the voices of the two are quite distinct; the call of the groove-billed is softer and higher in pitch, while that of the smooth-billed is more raucous and whining. The grooves in the bill of the former are not easily seen, except under favorable circumstances, but the culmen of the bill in the smooth-billed is much higher and sharper than in the groove-billed.

DISTRIBUTION
Range: South America and the West Indies; casual in winter in eastern Central America and casual or accidental in Florida, Louisiana’, North Carolina, and Pennsylvania.

The normal range of the smooth-billed ani extends north to western Cuba (Los Indios and Nueva Gerona); the Bahama Islands (Little Abaco and Nassau); Haiti (Jacmel); the Dominican Republic (Sesua and Ciudad Trujillo); Puerto Rico (Aguidillo and Rio Piedras); and the Virgin Islands (Cuelebra, Vieques, and St. Croix). East to the Virgin Islands (St. Croix) ; the Lesser Antilles (Grenada and Trinidad) ; British Guiana (Georgetown); Surinam (Paramaribo) ; and eastern Brazil (Ilha Mexiana, Maranhao, Bahia, Sapetiba, Canatgallo, Rio de Janeiro, and Igruap6). South to southeastern Brazil (Iguape); and northern Argentina (Posadas, the Chaco District, and San Josc). West to northwestern Argentina (San Jose, Concepcion, and Salta) ; Peru (Huanuco and Iquitos) ; northwestern Colombia (the Cauca River Valley); Panama (Gatun, Perme, and Obaldia) ; Jamaica (Port Henderson, Spanish Town, Grand. Cayman, and Little Cayman); and western Cuba (Los Indios).

This species occurs in other parts of Central America only in winter, when it has been recorded from Costa Rica. (Rio Coto) ; Nicaragua (Great and Little Corn Islands); Honduras (Ruatan Island); and Quintana Roo, Mexico (Cozumel Island).

Casual records: The following are among the several records the species has for Florida: Flamingo, a specimen taken in June 1916; Pass-a-Grille, a specimen collected on February 25, 1929; D~ry Tortugas, three seen June 18 and 19, 1935; and Miami Beach, a small flock seen on February 24, 1937. Undated specimens also are available for Brevard County, Tortugas, Pepper Hammock near the head of the Banana River, and Charlotte Harbor.

A specimen was collected on July 18, 1893, at Diamond, and several have been reported from the vicinity of Buras, St. Bernard Parish, La. A specimen was collected previous to 1866 at Edenton, N. C., while individuals were reported from Piney Creek in the western part of that State on July 17, 1932, June 1, 1933, and June 25, 1934. There also is an old record of the occurrence of this species on Pettys Island in the Delaware River, opposite Kensington, Pa.

Egg dates: Bahamas: 2 records, June 14. Brazil: 3 records, October I to November 18. British Guiana: 3 records, January 14 to July 2. Cuba: 4 records, February 22 to August 20. Jamaica: 7 records, May 29 to July 30. Puerto Rico: 2 records, July 25 and August 13.