ii4 BIRDS OF LA PLATA 



but whether in such cases the birds are paired or 

 practise a promiscuous intercourse I have not been 

 able to discover. They have a great partiality for the 

 large domed nests made by the Anumbius acuti- 

 caudatus, called Firewood-Gatherer in the vernacular, 

 One summer a flock of about ten Bay-wings took 

 possession of a nest on one of my trees, and after a 

 few days I took fourteen eggs from it. Though the 

 birds hopped chirping around me, manifesting great 

 solicitude, the eggs were quite cold, and had I left 

 them many more would have been laid, no doubt ; 

 but as they were piled up three or four deep in the 

 nest they could never have been hatched. 



As a rule, however, the flock breaks up into pairs ; 

 and then a neat, well-made nest is built in the fork 

 of a branch, lined with horsehair ; or, oftener still, 

 a domed nest is seised, the Bay-wings fighting with 

 great spirit to get possession, and in it, or on it, their 

 own nest is made. Like their relation, the Common 

 Cow-bird, they seem strongly attracted by domed 

 nests, and yet shrink from laying in the dark interior ; 

 as a rule when they have captured a large domed 

 nest they break a hole in the side and so admit the 

 light and form an easy entrance. 



The eggs of the Bay-wing are five in number, 

 nearly round, and densely marked with dusky reddish 

 brown. 



