208 
THE COxNDOR 
Vol. XIII 
{Sfiiniclla neglecta), western kingbird ( Tyrauuus verticalis) , blue-fronted jay 
{Cyanocitta stelleri frontalis) , and Say phoebe ( Sayoniis sayus). 
4. b'our out of five species found to feed on the butterfly are numbered 
among the birds whose usual food habits justly subject them to severe criticism 
from the farmer. 
5. The Brewer blackbird {Enphagus cyanocephaliis) was found to be the 
most efficient check both on account of numbers and food habits. When the com- 
parative number of individuals of the different species of birds were considered, it 
was found that the Brewer blackbird took 95 percent of all the butterflies eaten by 
birds. In this particular outbreak, therefore, one species of bird rather than birds 
in general, played the great'^st part in the destruction of the insect. 
6. The examination of thirteen stomachs of the red-winged blackbird 
ia/HS p/ioenicciis, subspecies?) showed over 93 percent of its food to be v^egetable 
matter, thus bringing out the vast difference in food habits between this bird and 
the Brewer blackbird ( Enphagns cyanocephaliis), 83 percent of whose food was 
animal matter. 
7. Eiigonia calitornica in the butterfly stage, probably on account of its 
large size, was not eaten by any species of bird smaller than the Say phoebe. The 
smaller birds probably had a more intimate relation to the outbreak when the in- 
sect was in the larval and pupal stage. 
8. The birds in feeding on the butterfly attacked the insect at a critical point 
in its life history and were therefore of more value as a check than they would have 
been had they fed on the larva or pupa. 
9. A comparison of the food of birds taken before the plague with that of 
birds taken while the plague was at its height, showed that birds had varied their 
food habits and had taken advantage of the abundant supply of insect food in the 
form of butterflies. Their value as checks in this particular insect outbreak, there- 
fore, was real. 
10. The data collected shows of what value birds may be in the checking of 
an insect outbreak rather than their value in the prevention of an outbreak. 
LITERATURE CITED 
Aiighey, S. 
1878. Notes on the nature of food of the birds of Nebraska. United .States Ento- 
mological Commission, First Report, Appendix II. 
Beal, F. E. L. 
1907. Birds of California, Part I. U. .S. Dept. Agric., Di\-. Biol. Snrv. Bull., No. 
,50, pp. 1-100, 3 pis. 
1910. Birds of California, Part II. Ibid., No. .54, pp. 1-96, 6 pis. 
tVeed, C. IM., and Dearborn, N. 
190,5. Birds in their relation to man (Philadelphia, Lippincott), viii, .580, pis. and 
text figs. 
FURTHER NOTES FROM SANTA CRUZ ISLAND 
By ALFRED B. HOWELL and A. VAN RO.SSEH 
T he topography of Santa Cruz Island is more varied than that of any other 
of the islands comprising the Santa Barbara group, and it has a corresponding 
diversity of bird life. Its greatest altitude is nearly three thousand feet; for 
the most part it is grass land with extensive barren stretches, and canyons fflled 
