196 ON SOARING FLIGHT. 



They will not, however, disperse, as a covey of partridges would do, 

 but will range back and forth, covering an area of perhaps from 5 to 10 

 acres of ground. Flapping flight will alternate with downward-gliding 

 flight, and whenever in gliding a vulture approaches the earth it will 

 be seen to rise again by turning upon a curve and flapping. Within a 

 very few minutes the birds will be found ranging less widely, their 

 flight will become more circular, stragglers will be drawn in, aud the 

 flock will unite into a more compact mass, covering perhaps an acre of 

 ground or less, and will move in circles varying from 40 to 200 feet in 

 diameter. Tlie entire flock will slowly rise to a height of from 100 to 

 200 feet, the amount of flapping becoming noticeably less. After reach- 

 ing a certain altitude the flapping will entirely cease, somewhat sud- 

 denly, and after that, it matters not how high they may rise, not a 

 bird, as a rule, will flap again. After rising to a height of perhaps 

 600 to 1,000 feet they will simultaneously disperse in all directions, no 

 two birds keeping company, and all gliding downward in direct lines 

 toward the earth, the altitude gained enabling each bird to glide a 

 distance of a mile or more without eftbrt of any kind. 



Following the flight of any one of the birds which have thus become 

 dispersed it will be found to make its way toward any flock which it 

 may see soaring. But if none is to be seen it will, on approaching the 

 earth, select a spot from which to rise agaiu as before, but it will rarely 

 be seen to flap its wings again. If other birds are in the neighborhood 

 they will join the one that is soaring aud all will rise together. The 

 spot selected may be a hillside, hilltop, valley, or plain, and the birds 

 will ascend with equal ease in any case, the selection of a spot from 

 which to rise being apparently a matter of indiliereDce to them. ' Given 

 the condition of a warm surface beneath them and they will quickly 

 begin soaring when frightened from a carcass, usually drifting with the 

 wind, which is here assumed to be light, aud rising within a very few 

 hundred feet of the spot; and this they will do day after day, wherever 

 the carcass may be located. But soaring above a carcass forms but a 

 small fraction of their daily flight, by far the greater part of their time 

 being spent in -searching for food; aud since they must be at all times 

 either rising in circles or descending at the rate of from 1 to 3 feet x)er 

 second it will be seen that when they have mounted to a height of from 

 500 to 1,000 feet, beyond which height the smaller vultures in temper- 

 ate climates do not habitually rise, it will take them but a few minutes 

 to reach the earth again if they cease to move in circles. Their descend- 

 ing flight is usually in a direct line, or in two or three broken lines, and 

 they will continue to descend until within perhaps 200 or 100 feet of the 

 earth. Allowing that the rate of descent is but 2 feet per second, a 

 bird will then have but little more than one miuute of time in which to 

 select a spot from which to rise again, for it is certain that if he con- 

 tinues to follow a straight course he will within less than two minutes 

 land upon the earth. Very often he will approach within 50 feet of the 



