108 MR. W. H. HUDSON ON THE HABITS OF RAILS. [Jan. 18, 



The Chajas {Chauna c^acarm) also sing in concert, "counting the 

 hours," as the Gauchas say ; for they sing about nine o'clock in the 

 evening and again just before dawn. 



Still more remarkable is the habit in the Scissor-tail (Milvulus 

 tyrannus) ; for these birds are not gregarious, and yet once a day they 

 rise up and, hurrying from tree to tree, summon each other to a 

 general gathering ; then, mounting with sharp chirping notes, they 

 precipitate themselves violently downwards from a great height, their 

 long tails opening and closing, their zigzag flight accompanied with 

 impetuous " whetting " and " grinding " notes. 



The Tinamous unite in small coveys and play, running about in 

 circles, rapidly doubling and suddenly crouching as if to conceal 

 themselves. 



Tyrant-birds and Thrushes chase each other screaming through 

 the air and amongst the trees. Hard-billed singing-birds sing in 

 concert on trees and bushes, and sometimes pursue each other and 

 fight all the time they are singing. Some Ducks fight mock battles 

 on the water. The habit is different in the Chiloe Widgeon (Mareca 

 chiloensis) ; for this Duck has an easy and powerful flight. lu small 

 flocks they rise until they become mere specks in the sky ; at that 

 vast height they hover, all the time singing their shrill notes, and close 

 and separate and close again ; and every time they close they slap 

 each other so smartly with their wings that the blows can sometimes 

 be heard when the birds have quite vanished from sight. 



Many mammals also have meetings and rejoice together, some 

 species even having set performances ; but the habit is less notice- 

 able in them, as they are not so impressionable by nature as birds, 

 and are also less buoyant in their motions, and less garrulous. 



In all the instances I have given, the sexual passion is in no way 

 concerned ; for these gatherings and displays take place at all seasons 

 of the year, and are in some cases less frequent during the season of 

 courtship. It is impossible to doubt that the cause is simply the 

 natural gladness felt by all sentient beings at times, when hunger is 

 satisfied and they are free from the restraints imposed by other 

 emotions. It is to a great extent an associate feeling, and, in species 

 accustomed to meet and to indulge in it with frequency, is instanta- 

 neously communicated from one to the other. Every shepherd and 

 herdsman on the pampas is familiar with the fits of joy that seize 

 his domestic or semi- domestic cattle. Thus a lamb in a flock will 

 suddenly spring up two or three times in quick succession, coming 

 down on his four feet together ; and instantly his companions become 

 possessed with a joyous contagion, and, breaking away from their 

 dams, they fly off in pursuit. Suddenly they all stop and group 

 themselves together; but in a few moments another lamb springs up 

 and bounds away, and the chase is renewed. 



It is not to be wondered at that some species should have not 

 only a definite and unchangeable manner of manifesting their joyous- 

 ness, but should give it such extravagant expressions as, for example, 

 the Ipecaha does, whilst in others it shows itself in the most 

 subdued manner or not at all ; for some animals are incapable of ex- 



