30 BULLETIN 107, U. S. DEPARTMENT OF AGRICULTURE. 
eaten 25 or more weevils in one stage or another, and 3 had also eaten 
a few pupae. 
Of the remaining items of animal food, caterpillars (5.59 per 
cent), ground beetles (4.2), and Hemiptera (mainly the small cicada, 
Platypedia putnami) (4.09) were most conspicuous. Weed seeds 
again were prominent, amounting to 22.3 per cent, while grain 
formed about 4-J per cent. 
Summary. — Though the individual vesper sparrow is unable to 
consume as many of the insects in question as some of his larger and 
more voracious neighbors, as Brewer's blackbird or the robin, its 
economic relation to the weevil is nevertheless important. During 
June and July it subsists on the pest to the extent of over half of 
its food, while from a fifth to a third more is composed of other 
equally injurious insects, together with weed seeds. The grain eaten 
is doubtless mainly waste. These birds, whose natural home is in 
the dry sagebrush areas, probably are just beginning to discover 
the food supply obtainable in alfalfa fields. As they become mere 
accustomed to visiting the alfalfa, we may expect them to render 
still greater service in the suppression of the pest. 
WESTERN SAVANNAH SPARROW. 
(Passerculus sandwichensis alauclinus.) 
The western savannah sparrow is to the average person an incon- 
spicuous individual in the bird life of Utah, even though fairly 
abundant in many sections. It is frequentl} 7 met in the Salt Lake 
Valley, but is much more common in the valley of the Weber, where 
in some fields it is the most abundant of the sparrows. 
In May, 1911, seven savannah sparrows were obtained. All but 
one had fed on the weevil, and this pest composed 72.42 per cent 
of the stomach contents. The larvae apparently were preferred, for, 
although adult weevils were common, they occurred at an average 
of only a little over one per bird, while the larval form was found 
at the rate of 21 in every stomach. One had eaten no less than 61 
of the green worms, the highest number recorded for the species. 
The remaining food, which, save a mere trace of rubbish, was en- 
tirely animal in character, verifies the claim that this bird is one of 
the most highly insectivorous of sparrows, and that " they take equal 
rank in this regard with such notable insect destroyers as the cat- 
bird, robin, and bluebird 'V The food other than weevil was de- 
cidedly in the bird's favor as a large part was caterpillars, fly larvae, 
plant lice, and some unidentified coleopterous larvae. 
1 Judd, S. D., The Relations of Sparrows to Agriculture, Bull. 15, Biol. Survey, U. S. 
Dept. of Agr., 1901. 
