206 PATAGONIAN EXPEDITIONS I ZOOLOGY. 



Drought and Grasshoppers unfortunately often come together, so that the 

 Gulls are not so useful as they would otherwise be. In dry summers, 

 when the insects are abundant, it is common to hear people wish for 

 rain, that the Gulls might come and devour the Locusts. Apparently Gulls 

 have been useful to man in the same way on the western plains of North 

 America. 



"The Gulls congregate in great numbers about ploughed grounds, fill- 

 ing the new-made furrow till it appears like a white line, hovering in a 

 cloud over the ploughman's head, and following at his heels, fighting, 

 screaming, buffeting, in a compact crowd. When feeding they invariably 

 keep up a great noise and screaming. Wilson's expression in describing 

 a northern species, that its cry 'is like the excessive laugh of a negro,' is 

 also descriptive of the language of our bird. Its peculiar cry is length- 

 ened and inflected a thousand ways, and interspersed with numerous 

 short notes like excited exclamations. When their hunger is satisfied 

 they fly to the nearest water, where they bathe, drink and preen their 

 feathers. Their ablutions over (in which they appear to take great de- 

 light), they retire to some open spot in the neighbourhood abounding in 

 short green grass. Here they sit close together with their bills to the 

 wind ; in still weather they also all look one way ; and the observer will 

 watch the flock in vain to find one individual out of this beautiful order. 

 It is remarkable that they do not stand up to take flight, but rise in the 

 air directly from a sitting posture. Usually they flap their wings twice or 

 thrice before the body is raised from the ground. 



"In some seasons in August and September, after a period of rainy 

 warm weather, the larvae of our Great-horned Beetle rise to the surface, 

 throwing up little mounds of earth as Moles do ; often they are so 

 numerous as to give the plains, where the grass is very closely cropped, 

 the appearance of being covered with mud. These insects afford a rich 

 harvest to the Teru-teni (Vanellus cayennensis], which in such plentiful 

 seasons are to be seen all day diligently running about, probing and dis- 

 lodging them from under the fresh hillocks. The Gulls, not having been 

 endowed with a probing bill, avail themselves of their superior cunning 

 and violence to rob the Terus. I have often watched their proceedings 

 for hours with the greatest interest. Many hundred Terns are perhaps 

 visible running busily about the plain on all sides ; near each one a Gull 

 is quietly standing regarding his intended dupe with the closest attention. 



