202 
THE CONDOR 
Vol. XIII 
frightened they perched in some nearby fir trees or on the telegraph wires. The 
third flock could always be found in the near vicinity of some meadow-land south 
of Sisson. Close observation failed to show them feeding on anything but 
butterflies. 
The stomach examination of the few Brewers taken at this time substantiated 
the fact that their food was made up almost entirely of the butterflies. The 
stomach of one bird taken very early in the morning, when examined, was found to 
contain five Itiigouia caJifoniica and parts of several others. A few grains of oats 
and parts of beetles were found in- the stomach of a bird taken in a meadow near a 
stubble field. Birds collected the latter part of June and July contained a large 
percentage of beetles but no larvae or adults of Kugoiiia ca/ifoniica . Considering 
the comparativ’e numbers of individuals of the different species of birds found to 
feed on the butterfly, the Brewer blackbird took 9o percent of the butterflies eaten 
by birds, the meadowlark 21^2 percent and the kingbird, blue jay and Say phoebe 
shared the rest. 
Only four western kingbirds ( Tyraumis verfical/s) were .seen. Two birds 
perched on the telegraph wires along a road, were watched for some time. One of 
them was .seen to catch two butterflies in the air. On another occasion two kingbirds 
were .seen in the same general location, probably the same birds. They continu- 
ally flew out from the wire and caught some insect in the air. As the air was 
filled with butterflies, it seems probable that these birds were catching them. Two 
kingbirds seen perched on a fence in a barnyard appeared also to be feeding on 
butterflies. It is to be regretted that no specimens are at hand for stomach exam- 
ination, as the supplementary evidence, thus obtainable, would have thrown light 
on the extent to which the kingbird acts as a check. 
Meadowlarks { Stiirnclla iicglecta) were so shy that except in one case, it was 
impossible to determine the kind of food taken. A lone meadowlark feeding 
with some Brewer blackbirds on the grass plot adjoining the station was seen to 
run after several butterflies and to catch one. In the examination of seven 
stomachs, onh- two showed the remains of butterflies. All of the birds whose 
stomachs were examined, were taken in meadows or cut fields of wild hay where 
other insect life was abundant. Beetles and grasshoppers formed the bulk of 
the food. 
A Say phoebe ( Sayoiiis sayiis) collected August 30, was found to contain a 
large butterfly of another species and also a Eiigonia califoniica, as well as some 
ants. Since 75 percent of the .stomach contents was composed of butterflies of dif- 
ferent kinds and since, according to Beal (1910), these insects form more than 10 
percent of the food of this bird for the year, it would appear that this flycatcher, as 
well as the kingbird, can be ranked as one of the checks on Eugouia calif arnica. 
Doubtless another large flycatcher, the ash-throated flycatcher ( Myiarchus ciner- 
ascois) , took its share of the butterflies, for it is known to feed to a considerable 
extent on butterflies and moths. No specimens of this species are available. 
If the food of the smaller flycatchers can be judged from that of the western 
flycatcher) difficilis) it is doubtful if they bore any relation to the out- 
break. The stomachs of the two western flycatchers examined, contained numer- 
ous small flies and a few small bees and beetles. A small white moth was found in 
one of the stomachs. Moreover it seems strange that a bird of its size should take 
so large an insect as the butterfly under discussion. No specimens of the western 
wood pewee {Myiochanes richardsoni) are at hand. Its food habits are known to 
be much like those of the western flycatcher. 
The red-winged blackbird {Age/aias phoeniceiis, subspecies ?) w^as very abund- 
