164 
NIGHT HAWK. 
a ploughed field, or in the corner of a corn field. The eggs 
are placed on the bare ground, in all cases on a dry situation, 
where the colour of the leaves, ground, stones, or other 
circumjacent parts of the surface, may resemble the general 
tint of the eggs, and thereby render them less easy to be 
discovered. The eggs are most commonly two, rather oblong, 
equally thick at both ends, of a dirty bluish white, and marked 
with innumerable touches of dark olive brown. To the 
immediate neighbourhood of this spot the male and female 
confine themselves, roosting on the high trees adjoining 
during the greater part of the day, seldom, however, together, 
and almost always on separate trees. They also sit length- 
wise on the branch, fence, or limb, on which they roost, and 
never across, like most other birds : this seems occasioned by 
the shortness and slender form of their legs and feet, which 
are not at all calculated to grasp the branch with sufficient 
firmness to balance their bodies. 
As soon as incubation commences, the male keeps a most 
vigilant watch around. He is then more frequently seen 
playing about in the air over the place, even during the day, 
mounting by several quick vibrations of the wings, then a few 
slower, uttering all the while a sharp, harsh squeak, till, 
having gained the highest point, he suddenly precipitates 
himself, head foremost, and with great rapidity, down sixty 
or eighty feet, wheeling up again as suddenly; at which 
instant is heard a loud booming sound, very much resembling 
that produced by blowing strongly into the bunghole of an 
empty hogshead ; and which is doubtless produced by the 
sudden expansion of his capacious mouth, while he passes 
through the air, as exhibited in the figure on the plate. 
He again mounts by alternate quick and leisurely motions 
of the wings, playing about as he ascends, uttering his usual 
hoarse squeak, till, in a few minutes, he again dives with 
the same impetuosity and violent sound as before. Some 
are of opinion that this is done to intimidate man or beast 
from approaching his nest, and he is particularly observed 
