18 MOTACILLID^E. 



found living within a few hundred yards of each other, showing how 

 strictly each bird keeps to its own little " beat "; for this difference in 

 coloration is, no doubt, due entirely to the amount of moisture in the 

 .ground they live on. 



The Cachilas are resident, living in couples all the year round, the 

 sexes being faithful. Several pairs frequent a small area, and sometimes 

 they unite in a desultory flock ; but these gatherings are not frequent. 

 In the evening, at all seasons, immediately after the sun has set, the 

 Cachilas all rise to a considerable height in the air and fly wildly about, 

 chirping for a few minutes, after which they retire to roost. 



When approached they frequently rise up several feet from the ground 

 and flutter in the air, chirping sharply, with breast towards the intruder. 

 This is a habit also found in Synallaxine species inhabiting the grassy 

 plains. But, as a rule, the Cachilas are the tamest of feathered 

 creatures, and usually creep reluctantly away on their little pink feet 

 when approached. If the pedestrian is a stranger to their habits they 

 easily delude him into attempting their capture with his hat, so little is 

 their fear of man. 



To sing, the Cachila mounts upwards almost vertically, making at 

 intervals a fluttering pause, accompanied with a few hurried notes. 

 When he has thus risen to a great height (but never beyond sight as 

 Azara says) he begins the descent slowly, the wings inclining upwards ; 

 and, descending, he pours forth long impressive strains, each ending 

 with a falling inflection or with two or three short throat-notes as the 

 bird pauses fluttering in mid-air, and then renewed successively until, 

 when the singer is within 3 or 4 feet of the earth, without alighting he 

 reascends as before to continue the performance. It is a very charming 

 melody, and heard always on the treeless plains when there is no other 

 bird-music, with the exception of the trilling and grasshopper-like notes 

 of a few Synallaxine species. But in character it is utterly unlike the 

 song of the Sky-Lark with its boundless energy, hurry, and abandon ; 

 and yet it is impossible not to think of the Sky-Lark when describing 

 the Cachila, which, in its manners, appearance, and in its habit of 

 soaring to a great height when singing, seems so like a small copy of 

 that bird. 



The Cachila rears two broods in the year ; the first is hatched about 

 the middle of August, that is, one to three months before the laying- 

 season of other Passerine species. By anticipating the breeding-season 

 their early nests escape the evil of parasitical eggs ; but, on the other 

 hand, frosty nights and heavy rains are probably as fatal to as many 

 early broods as the instinct of the Molothrus bonariensis, or Cow-bird, 

 is to others at a later period. 



