ARGENTINE COW-BIRD 85 
phaga and Wren to those of the Mocking-bird, vary 
so much in size and materials, and are placed in such 
different situations, the young Molothrus must have 
in most of them a somewhat incongruous appearance. 
But in the habits of the young bird is the greatest 
incongruity or inadaptation. When the nest is in a 
close thicket or forest, though much too small for 
the bird, and although the bird itself cannot under- 
stand its foster-parents, and welcomes all things that, 
whether with good or evil design, come near it, the 
unfitness is not so apparent as when the nest is in 
open fields and plains. 
The young Molothrus differs from the true off- 
spring of its foster-parents in its habit of quitting 
the nest as soon as it is able, trying to follow the old 
bird, and placing itself in the most conspicuous place 
it can find, such as the summit of a stalk or bush, 
and there demanding food with frequent and impor- 
tunate cries. Thus the little Flycatcher had acquired 
the habit of perching on the back of its charge to 
feed it, because parent birds invariably perch above 
their young to feed them, and the young Cow-bird 
prevented this by always sitting on the summit of 
the stalk it perched on. The habit is most fatal on 
the open and closely cropped pampas inhabited by 
the Pipit (Anthus correndera). In December when 
the Cachila Pipit rears its second brood, the common 
and abundant Carrion Hawk also has young, and 
feeds them almost exclusively on the young of various 
species of small birds. At this season the Chimango 
destroys great numbers of the young of the Pipit 
