Contributed by Charles Wendell Townsend
[Published in 1937: Smithsonian Institution United States National Museum Bulletin 167 (Part 1): -]
If one could forget the unsavory feeding habits of the black vulture
and remember only the pleasing attributes of its flight, one would
place this bird among the most distinguished and interesting of
avian friends. As a feature of the landscape in its flight and
soarings on high--and after all this is the feature most evident--the black vulture appeals to our aesthetic feelings, while the
mental effort needed in distinguishing it from the turkey vulture
and from larger hawks and eagles adds greatly to its interest. It is
a bird well worth seeing and watching.
Spring.-- As the black vulture is a resident throughout its breeding range except in the extreme northern parts, a marked spring migration does not occur. It seems to be fond of the neighborhood of the sea and generally outnumbers the turkey vulture in these regions, while it is outnumbered by the latter farther inland. As a straggler or wanderer it has been recorded as far north as Quebec and New Brunswick, while its breeding range extends north only as far as Maryland and Virginia.
Courtship.-- Aretas A. Saunders (1906) thus describes the courtship of this vulture, which "took place on the ground in the shade of a small lime tree": "In a circle in front of the female were three admirers, who, with their wings partly spread, were rapidly ducking their heads to her like well-trained servants. She paid little attention, and soon turned her back on them. They persisted in their attentions till she finally got disgusted and flew away, with her suitors in close pursuit."
Audubon (1840) gives a more graphic account as follows:
At the commencement of the love season, which is about the beginning of February, the gesticulations and parade of the males are extremely ludicrous. They first strut somewhat in the manner of the Turkey Cock, then open their wings, and, as they approach the female, lower their head, its wrinkled skin becoming loosened, so as entirely to cover the bill, and emit a puffing sound, which is by no means musical. When these actions have been repeated five or six times, and the conjugal compact sealed, the happy pair fly off and remain together until their young come abroad.
Simmons (1925) describes the courtship of the black vulture as observed in Texas:
During February and to the middle of March, the love-flight or courtship flight of the two birds may often be seen at the breeding grounds, lasting from two to ten minutes, in rapid, prolonged, wide-spreading circles. In the air over a thickly-populated nesting area, such as a honey-combed cliff or canyon wall in the hills, as many as 25 or 50 pairs may be seen going through these nuptial ceremonies during early March, presenting a slowly-moving, gyrating maelstrom, circling and sailing in close spirals, one of a pair continually following the other; out of this maelstrom a female occasionally drops, the male a few feet behind, and then a chase ensues, dropping, darting, wheeling with incredible speed, wing tips of one touching the wing tips of the other In the twists and turns of the play. A male performing before a female perched high on a dead tree overlooking the chasm often circles high in front of her, half folds his wings and dives straight for the earth, his wings shrilling and whistling until he zooms upward again to resume his circling.
C. J. Pennock writes: "What I take for a mating-time flight I have noted frequently in February and early March [in Wakulla County, Fla.], namely two birds in rapid flight in close company through the tree tops and open country, sometimes lasting three to five minutes."
Wayne (1910) says of South Carolina: "The birds mate in February, and when engaged in this pleasure utter a hissing sound which can be heard at a distance of several hundred yards."
S. A. Grimes sends us the following account:
I was returning home from a short trip to Baldwin Bay and noticed two vultures In a tall dead cypress in a swamp about 300 yards off the highway.
This aroused my curiosity, and I turned into a road that put me within 100 yards of the birds. Without getting out of the car, I focused my glasses on the birds and presently saw one hop over to the branch on which the other was perched. This bird, which was undoubtedly the male, alighted with his wings outstretched above his back and, holding them in this position, sidled up so close to the other that she was forced to back away on the limb. Losing her balance, she flopped to another branch and was followed by the male, who continued to hold his wings above his back in such a manner that the tips almost touched. The two birds "necked" a little, and the female pecked feebly at her mate's head and breast when he pressed her too hard out on the branch.
This performance was repeated four times, and each time I looked for copulation to take place, but the female was not agreeable. The male finally folded his wings and perched quietly beside his mate. They remained thus for about 15 minutes, each occasionally pecking gently at the other; and once I noticed that they grasped each other's bill, as doves are wont to do. I could plainly see, too, that the birds parted their mandibles repeatedly, as If making some sound, but none was audible at my distance. The birds suddenly sprang into the air and flapped away, after I had watched them 25 minutes. This was on January 31.
Nesting.-- The heading of this section is in a literal sense incorrect, for no nest is made by the black vulture, and the eggs are laid without this preparation. As bits of stick and weed stalks as well as dead leaves strew the ground in many places, the eggs may be deposited on these, but only incidentally, for these are not collected to form even the semblance of a nest, and there is no hollowing out of the ground as a receptacle for the eggs. Wayne (1910) called attention to an aesthetic habit of the bird that may have been peculiar to his region in South Carolina and that does not appear to have been noticed by other observers. He says: "It is a peculiar habit of this bird, which I have found to be almost constant, to have pearl, bone, and china buttons, as well as pieces of glass and figured china, around and under the eggs."
As there is no nest to hold the eggs, these cannot be placed on branches of trees but must necessarily rest on the firm foundation of the ground or at the bottom of hollow stumps, sometimes as much as 8 feet above the level of the ground.
Hollow stumps, access to which is only from the top, are commonly chosen for nesting by the black vulture. In some instances there may be an opening at the ground by which the bird may enter and leave. When the stump is 6 or 8 feet high and the nest is at ground level, the entrance and exit of the bird from this chimney-like structure must require the use of both the wings and feet, when the bird scrambles up and out. I was told by an ornithologist that once when a boy he climbed down for the eggs into one of these nesting sites, and was unable to get out until a companion came to his rescue. Edward J. Court (1924) reports a nesting "in a large white oak stump in a cavity about two feet below the level of the ground."
C. J. Pennock describes the nesting two years in succession of a black vulture "in a large decayed hollow tree, the entrance five feet above ground the eggs being placed on a level with the outside round. In every instance when the nest was visited, the brooding bird became alarmed at our approach, and we could hear her flapping to scramble up and escape at the elevated entrance."
J. B. Carroll, of Houston, Tex., says in a letter that he has seen many nestings in standing trees hollow at the base; "sometimes the eggs were at a level not far below the entrance, but I have known the eggs to be placed on the ground in the hollow, with the entrance six or eight feet up. Usually these entrance holes are not higher than that from the ground, but I have seen them as high as fifteen feet." A hollow in a standing tree sufficiently large even if at a considerable height above the ground might be used by this bird, and I was able to find one such record. Charles E. Stockard (1904) found the eggs of the black vulture "about sixty feet up in a huge poplar tree which stood in a cotton field that had been cleared for five years. In the crotch of this tree there was a large hollow running down about three feet and slightly sheltered above by the inclination of one of the limbs that formed the crotch. The eggs were deposited on the floor of this hollow. This was the only nest of this species that was observed more than a few feet from the ground. It is probable that the birds occupied this tree while it stood in the woods and when the land was cleared in 1897 the tree, being a large one, was deadened and left standing and the birds continued to use it as a nesting site." This is, of course, a very exceptional case. A still more unusual site is recorded by O. H. Baynard (1910), who in Florida found a black vulture incubating its eggs in a Ward's heron's nest in a cypress tree some 90 feet above the ground. As he collected the eggs, there is no doubt about the identity.
Where hollow stumps and standing trees occur, they seem to be favorite nesting sites for this bird, but elsewhere the eggs are laid on the ground, often in dense thickets of palmetto, yucca, tall saw grass, or small trees, although sometimes exposed to the full light of day in the open. The shade of a partly fallen tree trunk is another favorite site, as well as the shade of a rock or under boulders, and, especially in limestone country where caves abound, the eggs are often laid in a shallow cave on a cliff side.
In its nesting habits the black vulture is often gregarious, as shown in the following description by Walter Hoxie (1886) of the nesting on Buzzard Island, 3 miles from Beaufort, S. C., where a dozen or more pairs nested yearly:
There is never the slightest attempt at forming a nest, or even excavating a hollow. The eggs are laid far in under the intertwining stems of the yucca, and in the semi-shadows are quite hard to be seen. The parent birds, however, have a habit of always following the same path in leaving and approaching their precious charge, and after a little experience I learned to distinguish these traces so well that I seldom failed to follow them up and secure the coveted specimens. This track is seldom, If ever, straight It winds under and around the armed stems, and, the difference In bulk between a man and a Buzzard being considerable, the pointed leaves find a good many of a fellow's weak points before he reaches his prize.
Quite rarely I have found eggs on the other parts of the island, and once or twice in completely exposed situations, with not even an attempt to get under the protection of an overhanging bush. Possibly these belonged to young birds which had still much to learn in regard to ways of housekeeping.
Charles R. Stockard (1904) says: "The black vulture was found depositing her eggs in more widely different situations than any other bird observed. The favorite site was a large hollow log, or a tree having a huge hollow base with an opening only a few feet up, so that the female might be able to jump out of the nest." He notes the following nestings of this bird: "One pair for three seasons nested in a large hollow sycamore log that lay across a small stream and served as a 'foot log' for a little-used path in a swampy wood. At least three people a day must have walked over the log as the vulture sat calmly on her eggs." In another case "a set of two eggs was found lying on the bare ground under a large tree that had been uprooted and had fallen so that its trunk made an angle of about fifteen degrees to the earth. The eggs were placed below this trunk, which was four and a half feet above them, and thus slanting sun rays could have fallen upon the spot but for the heavy foliage of the wood." Two sets of eggs were found on the ground in a dense cane thicket. Another set was found in a cave in a steep clay bank bordering a creek. The entrance of the cave was 7 feet wide, it was 2 1/2 feet high, and ran back 6 feet. The eggs lay in the back of the cave.
James A. Lyon, Jr. (1893), writing of the limestone bluffs on the Cumberland River in Tennessee says: "The most of these bluffs have 'caves' or holes running back into them only two or three feet deep, others deeper. It is in these 'caves' that the black vulture usually deposits its eggs, though sometimes they are found under an overhanging ledge of rock. As a general rule they do not go far into the bluff, but lay near the entrance to the hole."
Eggs.-- [AUTHOR'S NOTE: The black vulture lays normally two eggs, occasionally only one and very rarely three. They vary in shape from ovate to elliptical-ovate or elongate-ovate, very rarely fusiform. The shell is smooth but not glossy. They can usually be distinguished from turkey-vulture eggs by being somewhat larger, having a peculiar ground color, and being much less heavily marked. The usual ground color is pale gray-green, sometimes pale bluish white or dull white and rarely creamy white. There are usually a few large blotches or spots, mostly near the large end or in a ring around it; some eggs are more evenly spotted and some are nearly immaculate. The markings are mostly in dark browns, "chestnut", "liver brown", or "chocolate", but sometimes in lighter browns, "russet" or "tawny", with occasionally a few "Quaker drab" spots. One very pretty egg is heavily blotched with "pale purple drab", with a few spots of "bay"; another is heavily blotched and finely spotted with "burnt sienna"; but such eggs are exceptional.
measurements of 51 eggs average 75.6 by 50.9 millimeters; the eggs
showing the four extremes measure 90.5 by 55.9, 75 by 56, 66.5 by
51, and 67.3 by 47 millimeters.]
Young.-- The incubation period is variously stated to be anywhere from 28 to 39 days; and both parents assist in the incubation. Baynard (1909) watching 21 nests found the incubation was usually 28 to 29 days, in one case 30 days. Edward S. Thomas (1928) reports it as about 39 days in one case. The young, helpless at first, may stray a little from the nest on the ground at a comparatively early age, but, according to Baynard (1913), they are about 14 weeks old before they are able to fly. Simmons (1925) quotes H. J. Kofahl's statement that the young remain at the nesting site for about 60 days. Howard Lacey (1911) says "the young feign death when disturbed."
The Rev. James J. Murray, of Lexington, Va., gives the following interesting account of an experience with young birds on the summit of House Mountain in Virginia, an elevation of about 3,000 feet:
The nest cavity was under a pile of huge boulders. The cave had an opening above large enough for a man to crawl into, and tunnels from two sides at the ground level. One of the parent birds flew out of the upper opening as we approached. There were two young birds, one somewhat larger than the other. They appeared to he three or four weeks old and to weigh about three pounds. They had no feathers and were covered with a thick down of cream buff color, almost reddish above. As we went into the hole they began to vomit large pieces of meat, almost choking in the effort, and continued to do so at intervals as long as we were there. They constantly made a loud blowing noise through slightly opened mouths. It was not a hiss but more like the noise of a bellows. At every effort to get them out into the open they scrambled back into the darkness, jamming themselves under the overhanging rocks and burying their heads in the cracks. When we finally pulled them out to the end of the tunnel in a vain effort to get a good picture in the dim light, they fought each other fiercely and pecked at our hands.
Edward S. Thomas (1928) describes the feeding of the young as follows:
The adult bird lowers its bill to the young, which immediately inserts its beak between the opened mandibles of the adult. The adult, with or without a perceptible gulping movement, regurgitates the food, which is eaten by the young with a nibbling movement of its mandibles. We were certain that at times the adult extruded broth-like drops of liquid, which the young secured from the scarcely opened mandibles of the old bird. At other times the young birds obtained the food from the middle part of the adult's beak, hut the preferred source of supply, without question, was far up in the corner of the old one's mouth, where the young birds thrust their bills whenever they were able to do so.
The adults fed either from a standing position, or while brooding the young. The day was cold and the old birds brooded almost continually. The young were fed repeatedly. Between the hours of 6:03 a. m. and 5:48 p.m., there were 17 distinct feeding periods, some of which continued over an interval of seven minutes or more.
The young were very matter-of-fact about taking their food, and at no time showed the eagerness, which characterizes the young of most birds. This perhaps may be accounted for by the fact that the young were kept gorged with food continually, the distended stomachs being plainly visible from the blind. On this occasion, the young apparently were fed liquid food only, the liquid being described by Geist as having a milky appearance. On several occasions, solid food, having the appearance of flesh or connective tissue, was regurgitated, which the young attempted to seize, but on each occasion the parent re-swallowed the material.
Plumages.-- [AUTHOR'S NOTE: The young black vulture is warmly covered except on the head, with long, thick, heavy down of a rich buffy color. Mr. Thomas (1928) says:
At 17 days the pinfeathers of the wing begin to show. At 39 days, the young were almost full-grown, but the wing quills were only five inches in length, and the tail feathers of the larger of the two birds, two inches. At this age, there were no other feathers. On June 12, when the young were about 52 days old, the scapulars, tertials and practically all of the wing coverts were feathered, and quills were appearing on the breast. A week later, the upper parts were practically covered, although there was still a great deal of down showing, hut while feathers were appearing on the breast dad under parts, they were concealed by the down. On June 26, at 66 days, one of the young was able to fly up to the top of the box blind. By July 4, they had left the cave, having a period of from 67 to 74 days in the nest.
Immature birds during their first year are much like adults, but the plumage is duller black and less glossy, and the naked skin of the neck and head is partially concealed by a scanty growth of short, black, hairy down. I have been unable to trace subsequent molts.]
Food.-- The principal food of the black vulture gives it its common
name of carrion crow, for carrion is the chief article of its diet.
This food is to be found in the sewers and dump heaps and about
butchers' shops in southern cities, as well as in the fields and
forests where animals have come to untimely ends. The methods used
in searching for and disposing of this food will be described
farther on under "Behavior." As scavengers, especially in
cities where these functions are not attended to by man, the black
vulture is considered a valuable servant. Black vultures will also
eat fresh meat, and butchers must watch their stalls carefully when
these birds are about.
J. D. Figgins (1923) found that black vultures in the neighborhood of Bird Island, La., were very destructive in some of the heron rookeries and stated that "it is a frequent occurrence to observe a vulture with a struggling young heron dangling from its beak. In regions where cattle raising has replaced the cultivation of rice, the Black Vulture is credited with considerable damage to the herds by tearing the eyes from calves at the time of birth and instances are cited of a like treatment accorded cows while in a weakened condition. I personally saw one of these tear the tail from a small pig, and was informed that the practice was of too common occurrence to excite comment." O. E. Baynard (1909) reported that these birds were very destructive to young pigs and lambs in Florida, and he has known them to take young chickens. Young herons are frequently devoured. Audubon (1840) says of his experience with the bird in Florida: "I observed them many times devouring young cormorants and herons in the nest."
The United States Biological Survey recommends local control where "through their predatory habits and concentrated numbers, both turkey buzzards and black vultures have become a menace to new-born pigs, calves, lambs, and kids" (Redington, 1932).
Although it is common knowledge that black vultures eagerly devour fresh meat at butchers' stalls, C. J. Maynard (1896) says of this vulture that they "are more emphatically carrion feeders than the latter described species [turkey vulture] and will seldom eat fresh meat but prefer to wait until decomposition has set in before beginning their feast. Thus I have frequently seen the Turkey Buzzards gather around the freshly skinned carcass of an alligator, and eagerly devour the flesh, while the Black-heads would wait until it had lain for a day or two in the broiling sun before they would attack it; then, when the odor from the decaying mass became insufferable to human nostrils, they would eat to repletion. They not only eat decomposed meat but feed upon animal excrement and various kinds of offal."
Behavior.-- When a carcass of an animal is discovered, black vultures gather at the feast, which in many cases they must share and fight for, not only among themselves, but with turkey vultures and sometimes with eagles and dogs. Alexander Wilson's (1832) classic description of one of these feasts on a dead horse near Charleston, S. C., is well worth quoting:
The ground, for a hundred yards around it, was black with carrion crows; many sat on the tops of sheds, fences, and houses within sight; sixty or eighty on the opposite side of a small run. I counted at one time two hundred and thirty-seven, but I believe there were more, besides several in the air over my head, and at a distance. I ventured cautiously within thirty yards of the carcass, where three or four dogs and twenty or thirty vultures, were busy tearing and devouring. Seeing them take no notice, I ventured nearer, till I was within ten yards, and sat down on the bank. Still they paid little attention to me. The dogs being sometimes accidentally flapped with the wings of the vultures would growl and snap at them, which would occasion them to spring up for a moment, but they immediately gathered in again. I remarked the vultures frequently attack each other, fighting with their claws or heels, striking like a cock, with open wings, and fixing their claws in each other's head. The females, and, I believe, the males likewise, made a hissing sound, with open mouth, exactly resembling that produced by thrusting a red hot poker into water; and frequently a snuffling, like a dog clearing his nostrils, as I suppose they were theirs. On observing that they did not heed me, I stole so close that my feet were within one yard of the horse's legs, and again sat down. They all slid aloof a few feet; but, seeing me quiet, they soon returned as before. As they were often disturbed by the dogs, I ordered the latter home: my voice gave no alarm to the vultures. As soon as the dogs departed, the vultures crowded in such numbers, that I counted at one time thirty-seven on and around the carcass, with several within; so that scarcely an inch of it was visible. Sometimes one would come out with a large piece of the entrails, which in a moment was surrounded by several others, who tore it in fragments, and it soon disappeared. They kept up the hissing occasionally. Some of them having their whole legs and head covered with blood, presented a most savage aspect. Still as the dogs advanced, I would order them away, which seemed to gratify the vultures; and one would pursue another to within a foot or two of the spot where I was sitting. Sometimes I observed them stretching their necks along the ground, as if to press the food downwards.
The black vultures are often obliged to share their feasts with turkey vultures, and, according to Golsan and Holt (1914), they always get the better of the latter in a quarrel. On the other hand, according to Audubon (1840), "should eagles make their appearance at such a juncture, the Carrion Crows retire, and patiently wait until their betters are satisfied, but. They pay little regard to the dogs." In tearing off choice morsels from the carcass with their bills the vultures brace their feet firmly on the ground and flap violently with their wings to aid them in pulling away.
Their movements on the ground are not graceful. Aretas A. Saunders (1906) graphically describes them as follows: "When the vulture is taking his time about getting around, he moves with a very solemn, sedate walk, carefully placing one foot in front of the other. When he is in a hurry, however, he slightly spreads his wings and indulges in what looks like hopping but is really a very one-sided run. At first sight he seems to put both feet on the ground at once, but in reality he puts down the left foot first and takes his long step with the right foot."
In the air, on the other hand, the black vulture is much more at his ease, but he is far inferior in flight to the turkey vulture, owing to his shorter wings and tail and to his greater weight. While the turkey vulture sails in majestic circles on motionless wings, borne up by the air currents, the black vulture on the same up-currents is obliged to flap his wings from time to time. If the up-currents are strong, his need for flapping is reduced, but he never equals the grace of the turkey vulture. I once compared the flight of the two birds on a calm warm day in Georgia, as they were soaring over a sparse pine forest. They were both about 60 yards above my head as I reclined on the ground and about 40 yards over the forest. The turkey vulture soared in small circles, neither rising nor falling and without once flapping its wings, which with the tail were merely adjusted from time to time to the air currents. The black vulture, on the other hand, flapped its wings quickly at frequent intervals. The contrast was very marked. After a while they both sailed off. Whether they were inspecting me as possible carrion I do not know. On another occasion, when lying outstretched on a sandy Florida beach, I was startled by the shadow of a vulture passing over me and at once sat up. I have been told that this is a habit of vultures to determine whether a body is alive or dead. That they fly near for this purpose is not improbable but one cannot believe that they are able to plan to have their shadow fall on the body.
When a black vulture flying and circling at a great height becomes aware of a carcass lying far below it, the bird at first circles down but soon drops with great swiftness, with legs hanging and, at times, wings flapping furiously. Such actions of descent from a height immediately attract the attention of other vultures on the ground or roosting in trees and they at once follow up the clue. One such action, even a mistaken one, can quickly collect a flock of vultures.
The question that has been much discussed then arises, as to how these birds find the carrion. It is evident that sight is of great importance, and the way in which vultures turn their heads in flight suggests that they are all the time on the lookout for their food. As carrion is so evident to our own sense of smell, even from a great distance, it is natural for us to suppose that these birds also are guided by the sense of smell, especially when trees or bushes partly conceal the carrion. In fact, this belief in the use of the smelling powers has always been a popular one, but since the experiments of Audubon and Bachman (1835) it has generally been accepted that sight alone guides the birds to their food. These experiments, made chiefly on the black vulture, are summarized briefly as follows:
(1) A carcass securely hid in a brier and canebrake was not detected by the birds, although the odor was very marked and attracted dogs.
(2) Carrion on ground covered by a frame of brushwood 12 inches above it was not detected by vultures who passed over it during the 25 days of the experiment.
(3) Fresh meat, placed on canvas covering carrion, was devoured by vultures standing on the canvas, but they did not detect the carrion.
(4) A blinded black vulture did not notice carrion placed within an inch of its nostrils.
A few observers since Audubon occasionally have tested the sense of smell in black vultures, but their findings are generally not conclusive, are not free from the possibility of error, and are often contradictory. Thus, C. J. Pennock writes to me that in Florida he placed "the offal from a large green turtle on the ground 15 or 20 yards within a grove of closely growing pine trees, averaging perhaps 50 feet in height and with tops thickly interlocked but with no side limbs for 30 feet up. At 8:15 a. m. the meal was ready; at 9 o'clock a single black vulture was atop the fence nearby; at 9:40 there were 40 birds, all black vultures sitting on the ground, perched in trees or regaling themselves. No vultures were in sight when the table was spread, and it was thought the repast could not be seen by a flying bird at the nearest open side of the grove, but of this there is a possible doubt."
Dr. Frank M. Chapman (1929) at Barro Colorado Island has made the latest and most careful experiments. Most of them were on the turkey buzzard, and he says that "some of my results leave no room for doubt that the turkey buzzard has a highly developed sense of smell. From others, exactly the opposite conclusion may be drawn." On one occasion two black vultures perched on a tree about 125 feet to leeward of a small house where carrion was concealed. These were the first black vultures he had seen alight on the island.
There is one source of error that so far as I know has not been considered in these experiments and may account for some of the contradictory results. This was brought out by Darlington (1930), who in collecting beetles by the use of carrion bait in tropical regions also attracted vultures, and was led to the following conclusions:
Soon after the death of an animal, except in unusual cases or during cold weather, the body attracts numbers of flies and beetles, some of which may continue to circle about It for several hours or days. The resulting congregation of insects is noisy and conspicuous, and of a sort which does not occur except about decaying material, so that it may be considered more or less characteristic of the latter. Since Vultures can undoubtedly see and perhaps hear such insect swarms at a distance, they have probably learned to recognize their significance, just as we recognize the significance of gatherings of the Cathartidae.
Aretas A. Saunders (1906) found that the lives of black vultures on a rubber plantation in Nicaragua followed a regular routine, influenced only by hatching and the character of the weather. Early in the morning they sat on fence posts or walked about the plantation in search of bits of food. At noon in fine weather they circled high in the air, coming down toward evening for another walk. At sunset they flew one after another to fence posts, thence to the top of a large tree, where they waited until all were congregated. All at once they flew to another tree and thence to another, until they found one to suit their fancy. They seldom slept in the same tree two nights in succession, though they always commenced operations from the same tree. Saunders continues:
Butchering day, which occurs at irregular intervals, is the important day in the life of the Vulture. As soon as the men go down to the potrero to drive up the cattle, they know what is coming. They gather together on the fence posts and shed roofs, watching the movements of the men with an air of expectancy. Sometimes they wait for three or four hours before the butchering is finished and the remains thrown out to them. Then there is an instantaneous scramble. Each Vulture takes hold with his beak and begins to pull and hiss and flap until the piece he holds breaks off, when it is swallowed as quickly as possible and a fresh hold taken. At this rate the whole feast is consumed in an hour or two, when the vultures go back to time fence posts and sit in silence for the remainder of the day.
Black vultures are very social in their habits and often resort to regular roosts. One such I visited at Buzzard Isle, Lake Lamonia, in northern Florida. The roost was in big live oaks, mostly dead, and at about 11 o'clock in the morning contained some 200 black vultures and half a dozen turkey vultures. The birds did not leave when I walked beneath them on a ground devoid of vegetation and covered with their droppings and many bones. The odor was strong of a chicken yard, but not of carrion. Toward sunset I saw from a distance a number of flocks of about 20 vultures each, sailing and flapping high up toward the roost. On another occasion on the Vermilion River, La., I passed at sunset about a hundred of these black creatures sitting on the limbs of moss-draped cypresses, many more in a nearby field and six or eight on the roof of a deserted house. A short distance away several were perched on the floating body of a dead cow. It was a mournful sight.
Audubon (1840) describes a visit by John Bachman and himself to a roost of black vultures that attended to the offal of Charleston, S. C. This roost was in a swampy wood of about two acres, across the Ashley River, two miles from the city. "When nearly under the trees on which the birds were roosted, we found the ground destitute of vegetation, and covered with ordure and feathers, mixed with the broken branches of the trees. The stench was horrible. The trees were completely covered with birds, from the trunk to the very tips of the branches." They estimated the number of vultures at several thousands.
Simmons (1925) states: "Just before daybreak, when a reddish glow begins to show in the eastern sky, black vultures begin to leave their roosts in the mountainous country, passing over in a continuous long string by ones and twos, or as many as half a dozen at a time, moving eastward towards the slaughter pens or to spread out over the open country and begin their tireless vigil for carcasses." They return just after sunset.
B. J. Blincoc (1922) observed an unusual flight of these birds in March in Nelson County, Ky., where the black vulture is generally scarce at this season. The flock of 92 individuals "presented a beautiful appearance as the birds soared in a spiral column, each bird taking, intermittently, a few short wing strokes. At times the whole flock in a long train coursed across country on set wings in an orderly manner suggesting the movement of a flock of water fowl, but not a bird moved a wing until they again maneuvered into a spiral column." There was not a single turkey vulture among them.
J. J. Murray (1928), at Lexington, Va., found about 60 vultures at a slaughter pen, and at least 40 of them, he says, were black vultures. "As we disturbed them, they began walking in single file in a long procession up a steep hillside for 200 or 300 yards, and then near the top took flight." In a letter he says: "This procession was not in order to reach a high place from which to take off, for many of them had jumped to the ground from the top of the slaughter house as the procession started." To rise from the ground in calm weather it is sometimes necessary for the black vulture to hop or run along for 20 or 30 feet, beating its wings violently until it is able to take off.
In cold weather these vultures often sit around chimney pots and on chimneys to obtain some of the warmth. In wet weather they present a most dejected appearance, with wings drawn in close to the body and with back and tail in an almost vertical position. They have a habit of spreading their wings and tail to dry and air when the sun is shining. When alarmed or caught they eject the contents of their stomachs with great quickness and power.
In southern regions it is unnecessary to bury a dead animal to prevent long pollution of the air, as in the North; the farmer merely drags the carcass to a secluded spot and the vultures soon strip off and consume the flesh and entrails. Around butchers' stalls and in cities where offal is thrown into the street, the birds are semi domesticated and walk around almost underfoot. Owing to these habits of the black vultures in consuming carrion and offal of all sorts, the danger of their spreading disease by pathogenic bacteria dropped directly from the vultures' feet and plumage, or by their dejecta, has been given serious consideration. If, for example, anthrax may be spread in this way from the carcass of a horse dead of that disease, it may be better economy to burn or bury the body than to leave it to the vultures.
Dr. Casey A. Wood (1922) relates an experience with black vultures in Georgetown, British Guiana, where until 1921 large numbers of them frequented the city, especially in the region of the slaughterhouses, and were to be seen daily perched on the roofs of the houses. The prejudice among the inhabitants in their favor as scavengers was strong, but it was found that the birds polluted the drinking water, which was largely supplied by roof drainage. It was proved that serious pollution of the drinking water was brought about by the birds' habit of bringing filth to the roofs and also by the pathogenic bacteria in their feces. Analysis of the cistern water of houses protected by wires stretched above the ridgepole to prevent roosting showed it to be free from pathogenic bacteria, while cisterns filled from unprotected roofs, especially those known to be patronized by black vultures, were often shown to be infected by horrific germs. Since 1921 the black vultures have been nearly banished from the city by shooting and systematic frightening away.
Herbert W. Brandt communicates the following about the turkey and black vultures in Kleberg County, Tex., where both are abundant: "It is claimed by Mr. Kleberg that they spread the deadly anthrax to the cattle, and also other cow diseases. He trapped 3,500 buzzards on the Laureles Ranch alone during the winter of 1918-19. The trap is simply a wire-enclosed yard with some foul smelling carcasses of cows, hogs, etc., as bait and an entrance that closes behind the bird and keeps it in. A Mexican then enters the trap with a club and kills the birds and burns the bodies."
In a publication of the Biological Survey (Redington, 1932), it is stated that "the Biological Survey has discouraged the general destruction of turkey buzzards and black vultures. These birds have been accused of being important carriers of livestock diseases, but skilled investigators have shown that the virus of charbon, or anthrax, is destroyed in passing through the digestive tract of the turkey buzzard. There also are on record similar data regarding the virus of hog cholera. Experimental work of the Bureau of Animal Industry has indicated that the transmission of hog cholera on the feet or feathers of birds is by no means so likely to occur as is generally supposed."
Voice.-- The black vulture is a very silent bird. Hissing, grunting, and blowing compose its entire vocabulary, and these sounds are rarely to be heard except when the birds are feeding or fighting. Aretas A. Saunders (1906) describes its voice as consisting of "a hiss and low guff, guff, guff, like a dog barking in the distance." Pennock describes a cry as sounding like watt or waugh. The blowing sound resembles that made by bellows. Donald J. Nicholson (1928) says that the young hiss at an intruder and utter a blowing note very similar to that of a rattlesnake. Edward S. Thomas (1928) writes:
The birds were beard to give a variety of notes. Adults and young, when cornered or annoyed, give a rasping, hissing snarl, also described as a "snore", and "half-way between a wheeze and a squeal" the young give this frequently in the presence of the parents. The young also frequently make a sound which, when they were very young, was described as "Phuh U' or "Whuh I" Later this note became in the older birds, "Woof I" or "Wooft I" This note apparently denotes suspicion, and may be the counterpart of a grunting sound which the adults frequently emit. In addition, I heard the adult give a low, croaking "Coo," very much like a one-syllabled coo of the domestic pigeon.
Field marks.-- When this bird is seen at close range, alighted on the ground or on a tree, it is unmistakable. Its black head and neck bare of feathers proclaim it to be a black vulture, although it must be remembered that the head of the immature turkey vulture is also dark and not red as in the adult. The other characteristics of the black vulture are best seen in flight. Here its short, nearly square ended tail, as contrasted with the longer rounded tail of the turkey vulture, is evident. The feet may sometimes be seen against the tail as they reach nearly to the end and even project a little, but it is more difficult to see them in the turkey vulture. The wings seen from above and below both show a light-colored space at the outer end of the primaries, while in the turkey vulture all the primaries and secondaries are light colored, giving the effect of a light posterior border to the wings. While the wings of the turkey vulture are held up at an angle in soaring, those of the black species are as a rule more nearly horizontal, and the ends of the primaries are more distinct and spread out like fingers. The heavier, clumsier flight of the black vulture, with frequent flappings of the wings, easily distinguishes the two birds, although in very favorable airs the black vulture may soar nearly as well as the turkey vulture.
Enemies.-- The black vulture is fortunate in having few if any enemies. Eagles and wolves may chase it away from a carcass, and ospreys may wrathfully pursue it if it appropriates a fish from the osprey's nest. Even man treats it with consideration in return for its services in cleaning up carrion and offal, although in time most southern cities may adopt the more sanitary but more expensive methods needed in northern cities in order to escape the defilements of these scavenger birds. In some regions, as has already been mentioned under "Food", it may be necessary for man to control these birds when they kill young domestic animals.
While smaller birds take alarm quickly at the sight of a hawk, they are not disturbed by the presence of these vultures. M. P. Skinner thus writes of a black vulture in a roost among the sand hills of North Carolina: "They never bothered small birds--wood ducks, blackbirds, meadowlarks and myrtle warblers among others--who seemed to know this and to be able to recognize the vulture readily. They showed no alarm at the vultures sailing over them, although quick to dive out of sight when even a small hawk appeared."
Black Vulture* Coragyps atratus atratus
*Original Source: Bent, Arthur Cleveland. 1937. Smithsonian Institution United States National Museum Bulletin 167 (Part 1): -. United States Government Printing Office