314 USEFUL BIRDS. 
which they do usually at some height, in rather a labored 
manner, keeping about the same level. The ordinary note 
is a sort of hoarse, loud chuck, and the song sounds much 
like the rather musical creaking of arusty hinge. They have 
also a metallic, jangling note, and when a number perch on a 
favorite tree and sing in chorus, 
the clanging and creaking they 
produce are indescribable. 
When not disturbed, they 
breed in companies, often in 
groves of white pine ; but where 
they are much shot at, they 
separate, and each pair finds a 
secluded place for its nest. As 
Fig. 140.—Crow Blackbird, male, soon as the young are reared, 
Sismnaraernantibty the birds gather in flocks of 
hundreds or even thousands, and forage together. In mi- 
gration they sometimes travel in immense armies. A great 
flight of these birds passed over Concord on Oct. 28, 1904. 
From my post of observation, on a hilltop, an army of birds 
could be seen extending across the sky from one horizon to 
the other. As one of my companions remarked, it was a 
great “rainbow of birds;” as they passed overhead, the line 
appeared to be about three rods wide and about one hundred 
feet above the hilltop. This column of birds appeared as 
perfect in form as a platoon. The individual birds were 
not flying in the direction in which the column extended, but 
diagonally across it ; and when one considers the difficulty of 
keeping a platoon of men in line when marching shoulder 
to shoulder, the precision with which this host of birds 
kept their line across the sky seems marvellous. As the 
line passed overhead, it extended nearly east and west. The 
birds seemed to be flying in a course considerably west of 
south, and thus the whole column was gradually drifting 
southwest. As the left of the line passed over the Concord 
meadows, its end was seen in the distance, but the other end 
of this mighty army extended beyond the western horizon. 
The flight was watched until it was nearly out of sight, and 
then Follawed with a glass until it disappeared i in the distance. 
