104 Birds Every Child Should Know 
Like the cliff swallow, the tree swallow is 
fast losing the right to its name. It takes 
so kindly to the boxes we set up for martins, 
bluebirds and wrens that, where sparrows do 
not interfere, it now prefers them to the hollow 
trees, which once were its only shelter. But 
some tree swallows still cling to old-fashioned 
ways and at least rest in hollow trees and 
stumps, even if they do not nest in them. 
Some day they may become as dependent upon 
us as the martins and, like them, refuse to nest 
where boxes are not provided. 
