BIEDS IN RELATION TO THE ALFALFA WEEVIL. 61 
The food habits of the leopard frog stamp it as one of the most 
beneficial of the lower vertebrates. Its only harm lies in the destruc- 
tion of beneficial predaceous and parasitic insects, but this is out- 
weighed by its persistent attack upon such insect pests as mosquitoes, 
crickets, grasshoppers, and the predaceous water beetles injurious to 
small fish fry. It is deplorable that so many of these batrachians 
are being slaughtered, either for fish bait or for the small morsel of 
food which their legs afford. 
CONCLUSION. 
The investigation of the food habits of the birds of Utah in rela- 
tion to the alfalfa weevil verifies the statement frequently made that 
the abundance of an insect, and consequently the ease with which it 
may be secured, are important factors governing the food habits of 
birds. With the exception of a few restrictions placed upon certain 
species by their methods of feeding, insectivorous birds are to a 
certain degree indiscriminate in their choice of food. Flycatchers, 
swallows, nighthawks, etc., are limited in a large measure to flying 
insects; thrushes, meadowlarks, blackbirds, and gallinaceous species 
secure most of their insect food from the ground; while warblers, 
chickadees, woodpeckers, cuckoos, etc., feed largely among the tree 
tops. It is the ground-feeding birds which come into most intimate 
contact with the alfalfa weevil, but birds that feed on the wing may 
secure the insect at the time of its spring and summer flights; and 
such species as search for their food over trunks of trees may come 
into contact with a few hibernating adults. Over much .of the terri- 
tory covered by the writer in his two seasons' work these bird enemies 
of the weevil had learned to search for the insect as a food in the 
comparatively short period of four or five years, a fact which makes 
the large proportion of this food eaten by some species the more 
remarkable. 
With the possible exception of a fungous disease, which in some 
localities destroyed large numbers of the pupse, there probably was, 
at the close of 1912, no other natural agency which had done more in 
holding the alfalfa weevil in check than the native birds. Being 
alert to detect any unusual abundance of suitable food in the insect 
world, they were among the first to turn their attention to this new 
pest, and when once a convenient supply of this food was found in 
the alfalfa these fields became popular with many species. It is 
quite possible that in the case of some of the birds examined a knowl- 
edge of the location of this insect had been only recently acquired, 
and a few years more experience with it would place these species 
much higher in the scale of weevil enemies. 
