ECONOMIC RELATIONS OF OUR BIRDS.                   563
136. EMPIDONAX FLAVIVENTRIS, BD. YELLOW-BELLIED        FLYCATCHER.
GROUP II. CLASS a.
A single specimen of this species was obtained at Worcester, July 26, 1876.
Dr. Hoy identified it at Racine, during the summer of 1869. Mr. Nelson speaks
of it as a common migrant in Northeastern Illinois. None of the fragments
of
five insects found in its stomach were identified.
FAMILY CAPRIMULGIDE: GOATSUCKEI.
FIG. 131.


NIGHT-HAWK (Chordeiles popetue). After Bd., Br. and Mldg.
Tabular Summary of Economic Relations showing the number of specimens
eating animal and vegetable food, and the number of insects taken from
the stomachs, classified as to economic relations under the heads Beneficial,
Detrimental and Unknown Relations.
NUMBER AND NAME OF SPECI-   CLASSIFICATION
MENS EXAMINED.           OF FOOD.          RATIOS REPRESENTED BY Lnms.
2         Animal food ......a
I)    | Vegetal food.
Of two Whippoorwills          Beeiil....
examined .Beneficial
2 Q0 10 Detrimental ......
2     141 Unknown.
| Animal food ......
JV  egetal  food  .........| .................
Of five Night-hawks I      I      Beneficial food
examined .......enfica.
2  0   8 Detrimental .
5      83 Up:.nown ..


I