ae & 
ECONOMIC VALUE OF BIRDS, 9 
we do not realize that Gulls and some other water birds 
are also beneficial as scavengers in eating refuse which, 
if left floating on the water, would often be cast ashore 
to decay. Dr. George F. Gaumer, of Yucatan, tells me 
that the killing of immense numbers of Herons and other 
littoral birds in Yucatan has been followed by an increase 
in human mortality among the inhabitants of the coast, 
which he is assured is a direct result of the destruction of 
birds that formerly assisted in keeping the beaches and 
bayous free from decaying animal matter. 
Lack of space forbids an adequate treatment of this 
subject, but reference to the works and papers mentioned 
below* will support the statement that, if we were de- 
prived of the services of birds, the earth would soon 
become uninhabitable. 
Nevertheless, the feathered protectors of our farms 
and gardens, plains and forests, require so little encour- 
agement from us—indeed, ask only tolerance—that we 
accept their services much as we do the air we breathe. 
We may be in debt to them past reckoning, and still be 
unaware of their existence. 
But to appreciate the beauty of form and plumage of 
* Notes on the Nature of the Food of the Birds of Nebraska, by 
S. Aughey; First Annual Report of the United States Entomological 
Commission for the Year 1877, Appendix ii. pp. 18-62. The Food of 
Birds, by S. A. Forbes; Bulletin No. 3, Illinois State Laboratory of 
Natural History, 1880, pp. 80-148. The Regulative Action of Birds 
upon Insect Oscillations, by S, A. Forbes, ibid.. Bulletin No, 6, 1883, 
pp. 3-32. Kconomic Relations of Wisconsin Birds, by F. H. King; 
Wisconsin Geological Survey, vol. i, 1882, pp. 441-610. Report on the 
Birds of Pennsylvania, with Special Reference to the Food Habits, 
based on over Four Thousand Stomach Examinations, by B. A. War- 
ren; Harrisburg, E. K. Meyers, State Printer. large 8vo, pp. 434, plates 
100. The English Sparrow in North America, especially in its Rela- 
tion to Agriculture, prepared under the Direction of C. Hart Merriam, 
by Walter B. Barrows; Bulletin No. 1, Division of Economic Orni- 
thology and Mammalogy of the United States Department of Agricul- 
