Method of Bird Study and Photography 21 



When the first edition of this work was published in 1901, I 

 had used the tent, with or without changing the nesting site, in 

 the case of twenty-six nests, belonging to fifteen Extent of 

 species of birds; the list is now extended to embrace Application 

 fifty -nine nests, belonging to thirty species, and the of the 



experiments, which have been continued through Method 

 five successive seasons (1899-1903), may be regarded as fairly 

 establishing the value of the method. That the extent of its 

 application is wide is equally clear. 1 In the entire list, which 

 is now tabulated for the benefit of future workers, the age of 

 the young is in most cases estimated from the data at hand, 

 which are only approximately accurate. 



EXPERIMENTS IN THE USE OF OBSERVATION TENT AND IN THE CHANGE 

 OF NESTING SITE. 



1 Mr. John B. Parker, of Cleveland, Ohio, has further successfully 

 applied the method to ten additional species, including the Field, Vesper, 

 and Grasshopper Sparrows, the Acadian Flycatcher and Wood Pewee, the 

 Goldfinch, Cardinal Bird, Yellow-billed Cuckoo, and the Cooper's Hawk, a 

 bird of an exceedingly shy and suspicious nature. 



Mr. Ned Dearborn, of the Field Columbian Museum, Chicago, has also 

 used the method with valuable results. (See Birds in their Relation to 

 Man, by Clarence M. Weed and Ned Dearborn; the J. B. Lippincott Co., 

 1903-) 



