BIRDS OF DURHAM AND VICINITY. 
61 
returned to the fence without alighting. The ice was broken, how- 
ever, and she quickly returned, this time to set foot on the shingle, 
and thereby express her satisfaction Avith the location. Frequently 
afterward, I found them together on the shingle, though it was 
several days before the nest was begun. Pewees, swallows, and 
swifts are especially interesting, because they have chosen to forsake 
their primitive haunts and come to dwell with man. Formerly, 
Pewees lived in the vicinity of v/ater, and nested on shelves of 
rocks, banks of earth, or among the roots of upturned trees. Now, 
since the land has become cleared, and flying insects are abundant 
everywhere, they are no longer obliged to live by water-courses, and 
while many still do so, yet many others live in field and farmyard. 
Very few indeed nest in the old places. Bridges and culverts are now 
resorted to by those which follow the water, while open sheds, barn 
cellars, and abandoned houses are utilized by very many. They have 
the nervous make-up peculiar to their tribe, evidenced by an incessant 
jerking of the tail. Although they do not essay to attack hawks, they 
keep a sharp eye out, and give instant warning when such aVi enemy 
comes in sight. 
Contopus borealis. Olive-sided Flycatcher. 459. 
The Olive-sided Flycatcher is only a migrant here, though it breeds 
in the more heavily timbered portions of the state. During the latter 
half of May and the first half of September it may occasionally be 
seen, generally on dead tops or branches of trees in unfrequented 
places. 
Contopus virens. Wood Pewee. 461. 
Wood Pewees are abundant summer residents in orchards and 
woods. They come late in May — two of my records say the twentieth 
and twenty-fourth — and leave in September. My latest record is 
September 15, when I saw three perched together in the dead top of a 
tree apparently contented, and it may have been several days later 
before they finally left. They usually spend the early part of the 
summer in the woods. After the young are on the wing, they come to 
the orchards and shade trees, and during August are sometimes one of 
the commonest birds along our streets. The nest is a low, lichen- 
covered structure, which looks so much like a natural growth on the 
branch supporting it, that it is difficult to find when the old bird is 
not at hand. 
