156 
BIRDS OF PENNSYLVANIA 
several weeks later took a batch of Screech Owl’s eggs out of it. An¬ 
other singular experience he had with owls is, he made a hole in a wil¬ 
low tree; when he came to look after it again he found owls had taken 
possession of it and had nearly filled it with field mice; he said there 
were enough mice in it to fill his derby hat. This happened just 
before a heavy snow storm and about ten days later every mouse was 
gone.” 
Mr. L. M. Turner informs me that he has made a number of exami¬ 
nations of Screech Owls captured in Illinois, and very generally found 
their food consisted of such insects as the larger beetles and grasshop¬ 
pers, also many mice. Grasshoppers and other orthopterous insects are 
devoured in large quantities by these birds. 
During the summer months and at other times when insect life is 
abundant the Screech Owls subsist mainly on an insect diet. These birds 
also prey* on mice, shrews, other small quadrupeds and small birds. In 
the twenty-seven stomach examinations, which I have recorded, of birds 
taken principally in the winter season, seventeen had fed on mice and 
insects; five, small birds; three, mice and insects; two, small birds and 
insects. 
Genus BUBO Cuvier. 
Bubo virginianus (Gmel.). 
Great Horned Owl; Hoot Owl. 
Description (Plate 19). 
Length (female) 21 to 24 inches ; extent about 5 feet; tail about 9 inches ; male 19 
to 23 long ; extent about 50 to 53 inches. Can be distinguished by its large size and 
long ear-tufts. Plumage blackish, brownish, dusky, grayish and whitish in mix¬ 
ture ; throat and middle of breast white. 
Habitat .—Eastern North America, west to the Mississippi Valley, and Irom Lab¬ 
rador south to Costa Rica. 
This well-known and rather common inhabitant of the forests can 
easily be recognized by its large size, the conspicuous white feathers of 
the throat and the long-ear tufts which measure 2| inches or more in 
length. The Great Horned, the largest of all our native owls, is the 
first to commence nesting. I have found its eggs in February, and am 
told that it occasionally lays in January. In this locality the Great 
Horned Owl seldom breeds in hollow trees; sometimes it constructs a 
rude and bulky nest of sticks, lined with grasses and feathers, on the 
large horizontal limbs of trees in its favorite wooded retreats. Its eggs, 
measuring about 2J inches in length by 2 inches in width, are mostly 
deposited in the deserted nests of hawks or crows. Although it is stated 
by different writers that this species lays four or more eggs, I have 
never found, in seven nests examined, over two eggs or a like number of 
young. Mr. Thomas H. Jackson, of West Chester, Pa., writing in the 
♦This species, and also the Great Horned Owl, is said to prey occasionally on fishes. 
f 
