HOW DO VULTURES DISCOVER THEIR PREY' 2c7 



is "by their keen sight that they generally find their food. Supposing that an animal is wounded, 

 and escapes from the hunter, his course is marked by a Vulture soaring high in the air ; another 

 circling far awav on the horizon sees the first bird fly down, and follows in his track; and so on, 

 until a large company is feeding on the carcase. This action of the Vultures is well described by 

 Longfellow : 



" Never stoops the soaring Vulture 

 On his quarry in the desert, 

 On the sick or wounded Bison, 

 But another Vulture, watching 

 From his high aerial look-out, 



Sees the downward plunge, and follows ; 

 And a third pursues the second, 

 Coming from the invisible ether, 

 First a speck, and then a Vulture, 

 Till the air is dark with pinions."* 



The power of the Vulture's sight was long disputed by the former generation of naturalists, 

 and the celebrated Waterton wrote an article on the " Faculty of Scent in the Vulture," f to prove 

 that it was more by this means than by sight that the bird was able to discover a carcase. Waterton 

 was well acquainted with Vultures in Demarara and in Southern Spain, and he sums up his argument 

 as follows : " After the repeated observations I have made in the country where it abounds, I am 

 quite satisfied that it is directed to its food by means of its olfactory nerves coming in contact with 

 putrid effluvium, which rises from corrupted substances through the heavier air. Those are deceived 

 who imagine that this effluvium would always be driven to one quarter in the tropics, where the trade- 

 winds prevail. Often, at the very time that the clouds are driving from the north-east up above, 

 there is a lower current of air coming from the quarter directly opposite. This takes place most 

 frequently during the night-time, in or near the woods ; and it often occurs early in the morning, 

 from sunrise till near ten o'clock, when the regular trade-wind begins to blow. Sometimes it is 

 noticed in the evening, after sunset ; and now and then during the best part of the day in the rainy 

 season. . . . Vultures, as far as I have been able to observe, do not keep together in a large flock 

 when they are soaring up and down in quest of a tainted current. Now, suppose a Mule has just 

 expired behind a high wall, under the dense foliage of evergreen tropical trees ; fifty Vultures, we will 

 say, roost in a tree a mile from this dead Mule. When morning comes, off they go in quest of food. 

 Ten fly, by mei'e chance, to the wood where the Mule lies, and manage to spy it through the trees ; 

 the rest go quite in a different direction. How are the last-mentioned birds to find the Mule 1 Every 

 minute carries them farther from it. Now reverse the statement ; and instead of a Mule nearly dead, 

 let us suppose a Mule in an offensive state of decomposition. I would stake my life upon it that not 

 only the fifty Vultures would be at the carcase next morning, but also that every Vulture in the 

 adjacent forest would manage to get there in time to partake of the repast." It will be seen from the 

 above that Mr. Waterton allowed the keen sight of the Vultures to play, on some occasions, a part in 

 their discovering food. Another observation 011 this subject is contained in the late Mr. C. J. Andersson's 

 work on the ornithology of South-western Africa. Writing on the Sociable Vulture (Otogyps auricularis), 

 lie says : " I believe naturalists are not quite agreed as to whether Vultures hunt by sight, by scent, 

 or by both faculties combined. I have myself no doubt that they employ the one sense as well as the 

 other in finding their prey, though I feel inclined to give sight the preference ; and I once had a very 

 striking proof of how they employ their vision in guiding them to carrion in this instance, however, 

 not so much by the actual sight of the can-ion (though the first discovery probably originated in that 

 way) as by another singular contrivance. Early one morning, as I was toiling up the ascent of a 

 somewhat elevated ridge of hills, with the view of obtaining bearings for my travelling map, and 

 before arriving at the summit, I observed several Vultures descending near me : but thinking I had 

 merely disturbed them from their lofty perch, I did not take any particular notice of their appearance, 

 as the event was one of usual occurrence ; but on gaining my destination, I found that the birds were 

 not coming merely from the hill summit, but from an indefinite distance on the other side. This 

 circumstance, coupled with the fact that I had wounded a Zebra on the preceding day in the direction 

 towards which the Vultures were winging their way, caused me to pay more attention. The flight of 

 die Vultures was low at least five hundred to a thousand feet below the summit of the mountain ; 

 and on arriving near the base, they would abruptly rise without deviating from their direct course; 



* "Song of Hiawatha," Book XIX. f "Essays on Natural History," 1866. p. 17. 



