570 THE AMERICAN NATURALIST. [VoL. XXXIII. 
Within a radius of an eighth of a mile of these two trees 
there are a number of evergreen trees, under which I found 
at various times considerable numbers of pellets ; since these 
proved to be not roosting but merely casual feeding perches, 
and since I found no other owls roosting in the vicinity, it 
would seem very probable that these pellets, or most of them, 
were produced by the owls observed by me. These pellets 
contained the remains of 5 small birds (including Regulus, 
Junco, Certhia), 3 Blarina brevicauda, 3 B. parva, 1 Blarina, 
undetermined, 2 Zapus hudsonius, 3 Peromyscus leucopus, I 
Microtus pinetorum, 139 Microtus pennsylvanicus, and 4 unde- 
termined individuals of Microtus. Pellets found under trees 
which are not day roosts would necessarily contain the remains 
of animals eaten by the owls in the early evening, before 
they returned to their roost. 
II. 
The very fact that pellets are found beneath trees which 
are merely feeding perches, as they have been termed by me, 
proves that the pellets beneath a roost do not represent all 
produced by owls. How great a proportion of all the food 
consumed is contained in the roost pellets cannot be deter- 
mined by field observation alone, since it is impracticable to 
follow and observe owls during their nocturnal wanderings. 
To determine how much food is eaten by owls, and how many 
pellets are disgorged away from their roosting places, I have 
compared my data with those given by Dr. A. K. Fisher in 
his very able and thorough work, “ The Hawks and Owls of 
the United States in their Relation to Agriculture” (U. S. 
Dept. Agric. Bulletin, No. 3, 1893). Dr. Fisher tabulates the 
results of the examination of several thousand stomachs of our 
rapacious birds. To-be sure, the number of objects found in 
an owl’s stomach do not necessarily represent all eaten by that 
owl in the course of a day. But since Fisher’s tables show per 
bird a somewhat higher average of food contents than do mine 
on pellets, his figures would approximate closer to the total 
food consumption per owl, and on this account the comparison 
of the two sets of data may be of interest. 
