GLIDING AMONG THE VULTURES

Wanganui Chronicle, Volume 80, Issue 254, 26 October 1937, Page 3

GLIDING AMONG THE VULTURES

Their Habits in the Air

J HAVE just returned from a business trip tu Johannesburg on which 1 svas fortunate enough to be able to take with me a Kirby Kile sailplane, jvrites Philip Wills in the Li.'teiivr. This is the first time in which a soaring Expedition abroad has been made by any but the Germans, and 1 was able lo do something to dispel the general I'elief overseas that they are the only country knowing anything about soarz sng - jBL They had never seen any thermal Soaring out there—that is, advancing by using currents of rising warm air caused by the sun’s heat on warm flays—and I did several thermal flights, •on one of which I reached a height of 5400 feet above the start, or 11,200 fe-et above sea level. | The most interesting discoveries I made, from the general point of view, Were regarding the methods of the vultures out thdre. The vulture has to face a problem very similar to that of the soaring pilot. He is a large and lieavy bird, and he has to be on the wing all day and every day. Up can’t be a very efficient snaring shape, because if you make yourself a superFoarer you become very bad at take offs and landings. This is whv th-’ albatross. the most efficient snarer in the world, has to limit himself to th< latitudes known the Roaring Forties, where there is always a wind to help /I’mi to fake off. On the land, or on a day, an albatross simply can’t get <-fT the ground at all. But the vulture has to take oft from the high veldt, six I’thousand feet up, and the air is still further rarefied by the heat. The solution be has arrived at is to go in for (thermal soaring and so make use of the great numbers of rising columns ol Warm air which are found in subtropical countries and which make things so very uncomfortable fur aeroplanes and so lovely for sailplane pilots. Tho vultures parcel out the air into areas about hulf-a-mile square, and Jjird A patrols his own territory, keep- 1

ing a sharp watch on neighbours B, C and D. They are on the look out foi two things—food, and a free lift from thermals. Suppose A suddenly spots a kill below. He hovers ami dives down at it. Instantly B, C and D d:t«h in. and their neighbours follow suit. As everybody knows, immediately an animal dies, the air becomes full of vultures, ami this is how it is done. But now suppose our friend A dis rovers a thermal. Immediately h n enters the rising air he starts to circle and climb; this is the signal for his neighbours, and in less than a minute he is the apex of a pyramid of wheeling mid climbing vultures. Of course, I made much use of this: whenever I saw a number of birds in a thermal I would fly over and join them. They were not in the least frightened, as they have no natural enemies in the air. What was unexpected, however, was that I found it was no one-sided arrangement in my favour. When 1 joined the soaring brigade T was accepted silently into the ranks. If T gatecrashed into A’s territory, he simply moved one along to B, B presumably moved over to C, and so on perhaps down to the coast four hundred miles away. When I saw A circling, I would go and join him. But if 1 found a thermal on my own, in less than a minute there would be a swish am] a large brown bird with a wicked face would come whizzing in and join me, and in no time T would be one of half-a-dozen or more birds, wheeling so close that T could sometimes see their eyes. If the thermal went higher than about 2500 feet, the bird*; would usually leave me. Evi deafly their comfortable range of vision is about 2500 feet, or half a-mile: though one aeroplane pilot told mo he had met a vulture at 10.000 feet. Tf 1 Lad pushed my stick forward and pu f my machine into a dive. T’m sure that in no time T would have had a train of shrieking birds on my tail looking for an imagined kill.