The above account of my experiments was read on the 16th day of December 1826, and was what I may call my "maiden speech." Well do I remember the uneasy feelings which I experienced: the audience was large, and composed of many of the most distinguished men of that enlightened country. My paper was a long one; and it contradicted all former opinions on the subject under discussion; yet the cheering appearance of kindness which every where met my eye, as I occasionally glanced around, gradually dispelled my uneasiness, and brought me to a state of confidence. The reading of the paper being at length accomplished, I was congratulated by the President, as well as by every member present. Many questions were put to me, all of which I answered as well as I could. My esteemed and learned friend, Professor Jameson, requested permission to publish my paper in his valuable journal, which I most readily granted. Strolling homeward, I felt proud that I had at last broken the charm by which men had so long been held in ignorance respecting the history of our Vultures, assured that the breach which I had made upon a general and deeply rooted opinion, must gradually dissolve it, as well as many other absurdities which have for ages infested science, like the vile grub beneath the bark of the noblest forest tree, retarding its growth, until happily removed by the constant hammerings of the industrious Woodpecker!
I returned to America, urged by enthusiasm, to pursue the study of Nature in the majestic forests; and finding that doubts excited by persons prejudiced against me, existed in the minds of some individuals, I resolved to have my series of experiments repeated by some other person, in those districts where Vultures abound, and in the presence of a number of scientific men, with the view of satisfying the incredulous as much as in my power. My travels were continued, and I became acquainted with one of the best practical ornithologists our country affords, and moreover a man of general learning, my worthy and esteemed friend the Reverend John Bachman of Charleston, South Carolina. To him I frequently wrote, requesting him to make experiments on the faculty of smelling in our vultures. In the winter of 1833-4, the following were made, and afterwards published in Loudon's Magazine of Natural History (No. 38, March 1834, p. 164).
"On the 16th December 1833, I commenced a series of experiments on the habits of our Vultures, which continued till the end of the month, and these have been renewed at intervals till the 15th of January 1834. Written invitations were sent to all the Professors of the two Medical Colleges in this city, to the officers and some of the members of the Philosophical Society, and such other individuals as we believed might take an interest in the subject. Although Mr Audubon was present during most of this time, and was willing to render any assistance required of him, yet he desired that we might make the experiments ourselves—that we might adopt any mode that the ingenuity or experience of others could suggest, at arriving at the most correct conclusions. The manner in which these experiments were made, together with the results, I now proceed to detail.
There were two points in particular on which the veracity of Audubon had been assailed, 1st, Whether the Vultures feed on fresh or putrid flesh, and, 2d, Whether they are attracted to their food by the eye or scent.
On the first head it was unnecessary to make many experiments, it being a subject with which even the most casual observer amongst us is well acquainted. It is well known that the roof of our market-house is covered with these birds every morning, waiting for any little scrap of fresh meat that may be thrown to them by the butchers! At our slaughter-pens, the offal is quickly devoured by our vultures, whilst it is yet warm from the recent death of the slain animal. I have seen the Vultur Aura a hundred miles in the interior of the country, where he may be said to be altogether in a state of nature, regaling himself on the entrails of a deer which had been killed not an hour before. Two years ago, Mr Henry Ward, who is now in London, and who was in the employ of the Philosophical Society of this city, was in the habit of depositing at the foot of my garden, in the suburbs of Charleston, the fresh carcasses of the birds he had skinned, and in the course of half an hour, both species of Vulture, and particularly the Turkey Buzzard, came and devoured the whole. Nay, we discovered that Vultures fed on the bodies of those of their own species that had been thus exposed. A few days ago, a Vulture that had been killed by some boys in the neighbourhood, and that had fallen near the place where we were performing our experiments, attracted, on the following morning, the sight of a Turkey Buzzard, who commenced pulling off its feathers and feeding upon it. This brought down two of the Black Vultures, who joined him in the repast. In this instance, the former chased away the two latter to some distance,—an unusual occurrence, as the Black Vulture is the strongest bird, and generally keeps off the other species. We had the dead bird lightly covered with some rice chaff, where it still remains undiscovered by the Vultures.
2d, Whether is the Vulture attracted to its food by the sense of smell or sight? A number of experiments were tried to satisfy us on this head, and all led to the same result. A few of these I proceed to detail.
1st, A dead Hare (Lepus timidus), a Pheasant (Phasianus colchicus), a Kestrel (Falco Tinnunculus), a recent importation from Europe, together with a wheel-barrow full of offal from the slaughter-pens, were deposited on the ground, at the foot of my garden. A frame was raised above it at the distance of 12 inches from the earth; this was covered with brushwood, allowing the air to pass freely beneath it, so as to convey the effluvium far and wide; and although 25 days have now gone by, and the flesh has become offensive, not a single Vulture appears to have observed it, though hundreds have passed over it, and some very near it, in search of their daily food. Although the Vultures did not discover this dainty mess, the dogs in the vicinity, who appeared to have better olfactory nerves, frequently visited the place, and gave us much trouble in the prosecution of our experiments.
2d, I now suggested an experiment which would enable us to test the inquiry whether the Vulture would be attracted to an object by the sight alone. A coarse painting on canvass was made, representing a sheep skinned and cut open. This proved very amusing;—no sooner was this picture placed on the ground, than the Vultures observed it, alighted near, walked over it, and some of them commenced tugging at the painting. They seemed much disappointed and surprised, and after having satisfied their curiosity, flew away. This experiment was repeated more than fifty times, with the same result. The painting was then placed within fifteen feet of the place where the offal was deposited; they came as usual, walked around it, but in no instance, evinced the slightest symptoms of their having scented the offal which was so near him.
3d, The most offensive portions of the offal were now placed on the earth; these were covered over by a thin canvass cloth; on this were strewed several pieces of fresh beef. The Vultures came, ate the flesh that was in sight, and although they were standing on a quantity beneath them, and although their bills were frequently within the eighth of an inch of this putrid matter, they did not discover it. We made a small rent in the canvass, and they at once discovered the flesh, and began to devour it. We drove them away, replaced the canvass with a piece that was entire; again they commenced eating the fresh pieces exhibited to their view, without discovering the hidden food they were trampling upon.
4th, The medical gentlemen who were present made a number of experiments to test the absurdity of a story, widely circulated in the United States, through the newspapers, that the eye of the Vulture, when perforated, and the sight extinguished, would in a few minutes be restored, in consequence of his placing his head under his wing, the down of which was said to renew his sight. The eyes were perforated; I need not add, that although they were refilled, and had the appearance of rotundity, yet the bird became blind, and that it was beyond the power of the healing art to restore his lost sight. His life was, however, preserved, by occasionally putting food in his mouth. In this situation they placed him in a small out-house, hung the flesh of the hare (which had now become offensive) within his reach; nay, they frequently placed it within an inch of his nostrils, but the bird gave no evidence of any knowledge that his favourite food was so near him. This was repeated from time to time during an interval of twenty-four days (the period of his death), with the same results.