26 BIRDS OF LA PLATA 



Swallow; but is so accustomed to the companion- 

 ship of man as to make its home in populous towns 

 as well as in country houses* It arrives in Buenos 

 Ayres about the middle of September, and appar- 

 ently resorts to the same breeding-place every year* 

 A hole under the eaves is usually selected, and the 

 nest is roughly built of dry grass, hair, feathers* and 

 other materials* When the entrance to its breeding- 

 hole is too large* it partially closes it up with mud 

 mixed with straw ; if there be two entrances it stops 

 up one altogether* The bird does not often require 

 to use mud in building ; it is the only one of our 

 Swallows that uses such a material at all* The eggs 

 are white, long* pointed, and five in number, 



In the season of courtship this Martin is a noisy 

 pugnacious bird, and always, when quitting its nest, 

 utters an exceedingly loud startling cry several times 

 repeated. It also has a song, uttered both when 

 resting and on the wing, composed of nine or ten 

 agreeably modulated notes, invariably repeated in 

 the same order. It is a pleasing song with something 

 of that peculiar human-like quality in the sound 

 which is so engaging in our Barn Swallow, But it is 

 a voice of much greater power and may be heard 

 when the bird sings flying at so great a height as to 

 be invisible. 



Before leaving in February these birds congregate 

 in parties of from twenty to four or five hundred, 

 their congregating place being usually on the broad 

 leafy top of an old ombu tree. 



