32 BURNED I. AUKS in RELATION TO AGRICULTURE. 
ation of tin 1 food habits of this subspecies indicates how powerfully 
local conditions, such a^ the abundance or scarcity of certain foods. 
affect the economic value of a bird. Horned larks, like other birds, 
naturally have recourse to the foods which are most abundant and 
most accessible, the ubiquitous wild oats being, in the case of the 
California birds, by far the greatest single (dement of their diet. 
In California, then, where they depend chiefly upon grain for food. 
the horned larks may do considerable harm, especially when they are 
very numerous. Elsewhere in the United States, other foods being 
generally abundant, grain is taken only incidentally and little injury 
is done. 
SUMMARY. 
Examination of 1,154 stomachs collected in all parts of the United 
States and southern Canada shows that the food of the horned larks 
consists <>f insects, 20.6 percent, and vegetable matter, nearly six- 
sevenths of which are weed seed. 79.4 percent. 
The nestlings are highly insectivorous, hut soon after leaving the 
nest the} r become much more vegetarian than even the adults. 
The horned larks of California differ markedly in food habits from 
those of other parts of the country, being almost entirely vegetarian. 
and although the number examined constitutes little more than a fifth 
of the total, yet they consume half of all the grain eaten by the whole 
group. Below are contrasted the amounts of grain eaten by the horned 
larks of California and of other States: 
Grain. 
California. 
Elsew here. 
Oats 
pi ret nt. 
31.1 
9.1 
Trace. 
None. 
l'i ret nt. 
i 86 
Wheat 
1 . (if, 
Corn 
i '.»: 
Buckwheat 
.68 
Total 
•10. 2 
12.2 
From the above facts and figures it might appear that the California 
horned larks are decidedly injurious, but the quantity of oats eaten as 
indicated by the ratios does not fairly represent the birds' economic 
status, since a huge proportion of this grain is wild and hence of no 
value to tin 1 farmer. 
Of the grain eaten in the other States, buckwheat is a negligible 
amount, while practically all of the corn and oats eaten is waste. 
Although the Great Plains region, the most important wheat-growing 
area of the country and also the center of abundance of the horned 
larks, is represented by a proportionate number of tin 1 stomachs 
examined. \ et the percentage of wheat eaten is only L.66. In fact, the 
