rid of the eggs of the Cowbird. As the egg is too large to be thrust out, the Yellow 

 Warbler commences a new nest above it. In one instance such reconstruction was twice 

 effected ; thus forming a nest of three stories." 



The clever method taken by the Yellow Warbler to baffle its persecutor indicates 

 intelligence of a comparatively high order, since most birds are easily imposed upon and 

 hatch and tend the greedy interloper to the ultimate destruction of their own offspring. 

 The young Cowbird, once established, is able, by reason of its superior size and strength, 

 not only to appropriate most of the food brought by its foster parents, but entirely to 

 dispossess its luckless companions by crowding them out of the nest, when, falling to 

 the ground, they perish miserably. 



