IX] THE ENEMIES OF BUTTERFLIES 113 



For North America Marshall records over 80 cases 

 of birds attacking butterflies. Among them is an 

 interesting record of a bird seizing and rejecting a 

 specimen of Anosia plexippus {=Danais archippus), one 

 of the few Danaines found in this region. 



It must be admitted that the data at present 

 available with regard to the attacks of birds upon 

 butterflies under natural conditions are too meagre to 

 allow of our coming to definite conclusions on the 

 points at issue. It is safe to say that a number of species 

 of birds have been known to attack butterflies — that a 

 few out of the number feed upon butterflies system- 

 atically — that some of the most persistent bird enemies 

 devour the presumably protected forms as freely as 

 the unprotected — but that in a few instances there is 

 some reason for supposing that the bird discriminates. 

 Beyond this it is unsafe to go at present. 



In attempting to come to a decision as to the part 

 played by birds in the destruction of butterflies an 

 evident desideratum is a knowledge of the contents of 

 the stomachs of freshly killed birds. Unfortunately 

 few systematic observations of this nature exist. 

 G. L. Bates^, when collecting in the Southern Came- 

 roons, noted the stomach contents of a considerable 

 number of birds. The remains of beetles were re- 

 cognised in 213 cases: Orthoptera in 177: ants in 57 

 (mostly in stomachs of birds of the genus Dendromus) : 

 other Hymenoptera in 8: coccids in 32: bugs in 19: 

 white ants in 31 : slugs and snails in 24: spiders in 85 



1 Ibis, 1911. 

 p. M. 3 



