SCREAMING COW-BIRD 99 
serving the habits of another species (Molothrus 
badius) I discovered by chance the procreant habits 
of the Screaming Cow-birds; and as these obser- 
vations throw some light on the habits of M. badius 
I think it best to transcribe my notes here in full. 
A pair of Lefiateros (Anumbius acuticaudatus), or 
Firewood-Gatherers, have been nearly all the winter 
building a nest on an acacia tree sixty yards from the 
house; it is about 27 inches deep, and 16 or 18 in 
circumference, and appears now nearly finished. I 
am sure that this nest will be attacked before long, 
and I have resolved to watch it closely. 
September 28.—To-day I saw a Bay-wing (M. 
badius) on the nest; it climbed over it, deliberately 
inspecting every part with the critical air of a pro- 
prietor who had ordered its construction, taking up 
and re-arranging some sticks and throwing others 
away from the nest. While thus engaged, two 
Common Cow-birds (M. bonariensis), male and female, 
came to the tree; the female dropped on to the 
nest, and began also to examine it, peering curiously 
into the entrance and quarrelling with the first bird. 
After a few minutes she flew away, followed by her 
glossy consort. The Bay-wing continued its strange 
futile work until the owners of the nest appeared, 
whereupon it hopped aside in its usual slow leisurely 
manner, sang for a few moments, then flew away. 
The similarity in the behaviour of the two birds 
struck me very forcibly; in the great interest they 
take in the nests of other birds, especially large 
