568 THE AMERICAN NATURALIST. (VoL. XXXIII. 
TABLE II. Norway SPRUCE TREE. 
DAILy 
Epiat NUMBER OF OWLS ON THE TREE CONTENTS OF PELLETS Foop 
AVERAGE 
Fob: 2 15 a1 ace. 
"m $ Lay 
Feb. 26 wto ¥ Meals. 50 Micr. penn. 
acai? Ra Ae A 
Lecter» nee Ge, 42 
Feb. 27, 1 wis. 
= 6 OB I wils. 1 Blar. parva 
Mar. 1, 1 wils. 1 Zapus 
Mar. 5 6 2, 1 wads. 1 Cambarus 2427 
ae a Gs 1 Finch (?) 
ogee “UT 27 Micr. penn. 
a ee fe eth T O., 
Mar. 6, I act. 1 wils. 1 Passer domesticus 
Mar. 14 oo ee ore 1 Melospiza fasciata 
eS Re OP 1 Blar. parva 
cdg TC 18 Micr. penn. 
Mar. 15, I ace. 
Mar. 19 ‘ . i ae : se Br SER 1.2 
6 Micr. penn. 
ohare ene IY er 
gig i I ace. 
Mar. 20; ? 
anor 3 I ace 
Oo ey vi ae, i 
Mar. 26 “ 23 Tae 1 Bird 57 
“oa tae 4 Micr. penn. 
ee o ra 
u s0, et ae 
vertical column gives the date of collection of pellets; the 
second, the number of owls on the tree each day; the third, 
the contents of the pellets; the fourth, the number of small 
mammals (mice and shrews) eaten by each owl daily. This 
number was ascertained at each period of collection of pellets, 
by dividing the total number of mammals by the number of 
days when owls were present on the tree, and dividing the 
