438 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1911. 



III. — ALIGHTING. 



The act of alighting appears to be not the least difficult part in the 

 performance of flight; indeed, whether it be regarded from man's 

 standpoint or from the bird's, it may well be accounted the most 

 difficult. 



On a boisterous day when a bird wishes to alight at some particular 

 point, its powers are often taxed to the utmost. The obvious signs of 

 this being so are the abrupt and spasmodic turns, and the flapping of 

 the wings, and the jerky, erratic course immediately preceding the 

 alighting; while not infrequently the clumsy and hurried actions on 

 touching the ground, plainly show how comparatively little the flight 

 had been under control the moment before alighting. 



That this is a real difficulty of which the birds are fully conscioua 

 is, I think, shown by their preparing for alighting long before they 

 actually do so. Their first care is apparently to reduce their speed 

 as much as possible, so as still to leave them sufficient "way" to 

 insure some stability in the air, and some power of guidance. They 

 soar round and round or approach slowly on a long, wavering course, 

 trailing their feet as brakes, or advance in a vertically zigzag course, 

 finding much resistance in short but steep ascents. But even after 

 these and many other preliminary devices have been tried, birds 

 often get sadly knocked about on really boisterous days when alighting 

 on the cliffs. The difficulty lies not so much in the mere act of 

 alighting, as in the settling at some particular spot. A bird must 

 slow up, or the impact would be too great for its leg muscles to cope 

 with; and the difficulty is that when slowing up and almost at a stand- 

 still in the air, so to speak, it is greatly at the mercy of the air cur- 

 rents — a swirling gust of wind being able then to carry it tins way 

 and that, whereas were it in full flight an equal gust might hardly 

 affect its onward course. I have seen guillemots and puffins when 

 on the point of alighting, and despite their rapidly beating wings, 

 bodily blown over in the air and hurled backwards 30 feet from where 

 they intended to set foot. Frequently, too, a bird, in wild weather 

 or when agitated, will fail to effect a landing, on a cliff for example at 

 the first attempt, perhaps finding it has too much pace to risk a contact 

 with the rocks, or, having too little, a gust of wind will "take hold" 

 of it and bear it past the place it intended to alight upon. 



As when dealing with "Taking flight," I illustrated my remarks 

 by photographs of the gannet, it may be well now to continue with 

 the same bird, and to try to follow some of its actions when alighting. 



In plate 6, figure 2, the gannet is approaching, intent on alighting. 

 The pace is comparatively slow, and is being continually lessened, 

 and the course of the bird is being steadied by the trailing feet. The 

 position of its home is not indicated in the picture; it was on the 



