REPORT OF THE CHIEF OF THE BUREAU OF BIOLOGICAL SURVEY. 



U. S. Department of Agriculture, 



Bureau or Biological Survey, 

 Washington, D. C, October 17, 1911. 



Sir: I have the honor to sMhmit herewith a report on the work of 

 the Biological Survey for the fiscal year ending June 30, 1911, with 

 an outline of the work for 1912. 



Respectfully, Henry W. Henshaw, 



Chief, Biological Survey. 

 Hon. James Wilson, 



Secretary of Agriculture. 



WORK OF THE BIOLOGICAL SURVEY. 

 INCREASING THE NUMBER OF NATIVE BIRDS. 



During the year circulars have been issued calling attention to 

 the fact that certain of our native birds appear to be diminishing 

 in numbers. This applies particularly to game birds, but it is true 

 also of some of the more valuable insectivorous species and of shore- 

 birds. Moreover, it is doubtful if, taking the country as a whole, 

 any of our native species are increasing, except perhaps in restricted 

 localities. This is the more deplorable, inasmuch as now, more than 

 ever, there is pressing need of the services of insectivorous birds to 

 hold in check the constantly increasing numbers of insects im- 

 ported from abroad or that cross our borders from adjacent terri- 

 tory. As these destructive foreign insects are rarely accompanied 

 by the enemies which check their increase in their native habitat, 

 they soon multiply till they become veritable pests. Nature has 

 provided in this country a sufficient number of species for the work 

 of keeping insects in check, including the various swallows, fly- 

 catchers, thrushes, woodpeckers, sparrows, and others, and it re- 

 mains for us by vigorous and concerted effort not only to protect 

 tlie useful species, but to enable them to so increase that their war- 

 ff.re against the insect hosts shall be thoroughly effective. This can 

 best be effected in four ways: 



(1) By providing artificial nesting sites for the species that nest 

 171 hollow trees or in the cornices and cavities of buildings. To some 

 slight extent this is already being done in this country, but to obtain 

 appreciable results provision must be made on a much larger scale. 

 It is well within the capabilities of the average farmer boy, when 

 furnished with a few necessary tools, to make nesting boxes for some 



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