THE YELLOW-HEADED BLACKBIRD. 31 
data regarding the food. As indicated by the contents of these 
stomachs, the food for the seven months consists of 33.7 percent of 
animal (insect) matter and 66.3 percent of vegetable matter. The 
animal food is composed chiefly of beetles, caterpillars, and grass- 
hoppers, with a few of other orders, while the vegetable food is made 
up almost entirely of grain and seeds of useless plants. Predaceous 
beetles (Carabidee) constitute 2.8 percent of the season’s food, a very 
small amount for a bird of such pronounced terrestrial habits. Most 
of these beetles are eaten in May, June, and July, and none are taken 
in the fall months. Other beetles amount to a little more than 5 per- 
cent, and are eaten mostly in the early part of summer. Caterpillars 
constitute 4.6 percent, but nearly two-thirds of them are taken in 
July, and in that month they form 21.5 percent of the month’s food. 
Remains of the army worm (Leucan/a unipuncta) were identified in 6 
stomachs. Grasshoppers are first eaten in May, but do not amount to 
any important percentage until July, the month of maximum con- 
sumption. In this respect this bird appears to differ, like the bobolink, 
from most other species, as August is usually the month in which 
grasshoppers are eaten most freely; but the examination of a larger 
number of stomachs might prove the yellowhead to be no exception to 
the usual rule. After August the consumption of grasshoppers is 
considerably increased, and the total for the season is 11.6 percent. 
The remainder of the animal food, 9.7 percent, is made up of other 
insects, chiefly Hymenoptera (ants, wasps, etc.), with a few dragon- 
flies and an occasional spider and snail. 
So far as its animal food is concerned, the yellowhead has a very 
good record. For a ground feeder, it takes very few predaceous 
beetles, while insects harmful to vegetation constitute 30 percent of 
its food. 
The vegetable food consists almost entirely of seeds, and for eco- 
nomic purposes may be divided into grain and weed seed. Of grain, 
oats hold first place, as in the food of the redwing, and are probably 
eaten in every month when they can be obtained, although none were 
found in any of the 5 stomachs taken in September. The 3 October 
stomachs contained an average of 63 percent, but a greater number of 
stomachs would in all probability give a smaller average. August, 
apparently the next month of importance, shows 43.2 percent. Next 
to oats corn is the favorite grain, and was eaten to the extent of 9.8 
percent, nearly all in the months of April, May, and June, with a 
maximum of 48.8 percent in April, when no wheat was eaten. Wheat 
appears from May to August, inclusive, and is the only vegetable 
food that reaches its highest mark in August. The average for the 
season is 3.5 percent. 
Grain collectively amounts to 38.9 percent, or considerably more 
than half of the total vegetable food, and more than one-third of all 
