520 
ECONOMIC RELATIONS OF OUR BIRDS. 
actual count, ranged from seventy to one hundred and one, and was usually 
nearly one hundred. Assuming that these constituted a whole day s food, the 
thirty birds were destroying three thousand worms a day, or ninety thousand 
for the month during which the caterpillar is exposed.” 
Family YIREONID-®: Gkeenlets. 
Fig. 121. 
Ekd-eted Greenlet {Vireo olivaceus). After Baird, Brewer and Ridgway. 
Tdbvlar Summary of Economic Relations showing the number of specimens con¬ 
taining animal and vegetable food, and the number 
contained in the stomachs, classified as to economic relations under the heads 
Beneficial, Detrimental and Unknown Relations. 
Number and Name of Speci¬ 
mens Examined. 
Of forty-nine Red-eyed 
Vireos ^ examined .. 
ClASSIFICATION 
OF Food. 
47 
14 
'd 
0) 
Animal food. 
Vegetal food. 
6 
3 
8 
Beneficial. 
37 
a 
o 
o 
145 
Detrimental. 
32 
116 
Unknown. 
Ratios Represented by Lines. 
Of sixteen Warbling 
Vireos examined.. 
Of twenty-one Yellow- 
throated Vireos ex¬ 
amined . 
16 
1 
10 
5 
21 
13 
13 
u 
S3 
o 
O 
Animal food. 
Vegetal food 
1 
41 
11 
.g 
13 
O 
O 
23 
55 
Beneficial 
Detrimental 
Unknown 
Animal food 
Vegetal food 
Beneficial 
Detrimental . 
Unknown. 
1 Scale reduced one-half for the Red-eyed Vireo 
