PREFACE. 



IN studying the habits of wild birds two important problems are at once encountered, 

 that of approach and the control of the position of the nest. Mv first e.xperiments 

 were made with Redwing f^lackbirds and Cedar Waxwings, and I soon perceived 

 that an important principle was involved, which every subsequent experiment tended to 

 confirm. Wishing to test its value as fully as possible, every available nest which came 

 to hand was utilized, without the exercise of choice in regard to species. 



The observations were made for the most part in central New Hampshire, in the 

 towns of Northfield and Tilton, and pertain to the common birds of the countr}'. 

 I am indebted to my sister for many practical and valuable suggestions. 



Francis Hobart Herrick. 



Western Reserve University, 



Adelbert College, Cleveland, Ohio, April, lyoi. 



