280 LAND-BIRDS AND GAME-BIRDS 
instantaneously, though sometimes obliged to give chase, which 
they do most adroitly. They often resort to the edge of ponds 
or streams, where gnats or mosquitoes abound. In feeding 
from a swarm of very small insects, they frequently hover with 
the body almost erect, and sustained by a rapid beating of the 
wings. Their flight is quite characteristic, but cannot be well 
defined ; it is rarely protracted, unless directed toward their 
nest. They never alight on the ground, unless to pick up some 
material for building, or to perch upon a heap of earth. In 
autumn, they are not confined to their usual haunts, but wander 
quite freely about the country, though rarely to be found in 
woods. I have never seen them near Boston later than the 
sixteenth of October, and a majority pass to the southward 
much earlier. 
(ad). The Pewees possess a greater variety of notes than a 
superficial observer would suppose. They have a loud chip 
(more or less characteristic), being, I believe, the only non- 
oscine (or unmusical) birds who possess this note. ‘They have 
also a whit, a single rather melancholy whistle, but seldom 
heard, and various twitters, of which some are querulous and 
others not unlike those of the King-bird. Besides these sounds, 
of which the latter are heard chiefly in spring, they utter quite 
constantly during the breeding-season, though much less often 
in summer, and rarely in autumn, their familiar and cheerful 
note, pee-wee, which is subject to more or less modification. 
Occasionally, in April, a Pewee darts into the air, and, hover- 
ing or fluttering in a circle, repeats this note so rapidly and 
excitedly as to produce eccentric music, which might almost 
without impropriety be called a song. There is, I believe, 
nothing which I can say to endear these birds to the naturalist, 
more than they are now endeared to all who know them. 
Iv. CONTOPUS 
(A) BoreaLis. Olive-sided Flycatcher. 
(A rather rare summer-resident.) 
(a). About 71 inches long. Tail considerably forked; 
crown-feathers erectile and dark-centred. Above, of an inde- 
