326 Wood, Autumn Warbler Migration. [july 



reluctance of some adult birds to leave their summer quarters. A 

 few adult male Yellow Warblers remain here at least two weeks 

 after the last young bird has departed but, as the last of certain 

 northern species may be represented by either or both adult and 

 young, it would seem as if some of the lingering adults influenced 

 a few juveniles to remain with them and sometimes left the trusting 

 youngsters far in the rear in the wild panic to flee the country. 



Satisfactory data, relative to the general distribution of autumn 

 warblers, can only be acquired by the liberal use of a gun. Little 

 reliance can be placed in field-glass observation and I doubt if 

 anyone, familiar with the family, is willing to accept such records 

 as positive in unusual cases, as when birds are exceptionally early, 

 late or rare. Of course the adult males of a few species can be 

 identified with certainty and a bird student, with enough knowledge 

 to have any business in the field, should know the Myrtle in all 

 plumages but he can get no accurate idea of the number of species 

 in his neighborhood, their relative abundance, etc. In just one 

 autumn I established a better knowledge of the warblers here than, 

 other parties in fifteen years of field-glass observation. 1 In order 

 to decrease the mortality I used a field-glass as much as possible. 

 It was very useful when warblers were near the ground or in trees 

 to the height of about thirty feet, if the birds possessed distinctive 

 under markings. However, it was practically useless at that 



1 1 mention this because my admission, in a previous paper, of having taken speci- 

 mens aroused the indignation of a certain class and appealing letters were sent to 

 the state game warden and others. I was born a lover of birds and have always 

 taken an interest in their welfare, but when it becomes necessary to secure them in 

 order to do certain work well, I feel justified in doing so. However, discussion is 

 futile but the above class should know that birds will be taken for some time to come. 

 Probably the most effective method of determining routes is "bird tagging," and 

 sooner or later a society will be organized to take up this work, and effective results 

 will depend almost entirely on birds secured; furthermore, much material is at pres- 

 ent required to permanently establish the subspecies and define their ranges. It 

 is true that some disapprove of this "hair splitting" but for no good reason that I 

 can see, except tiny are not interested in the subject or know nothing in regard to 

 it. However, in this, as in other branches, you can not suppress the taste for knowl- 

 edge and it is better to work out the problem soon as possible than allow it to drag 

 along with forms accepted and then rejected as in the past. In his great work 

 'The Birds of Middle and North America,' Prof. Ridgway laments the lack of 

 material not only in the foregoing connection but even in establishing plumage 

 variations of actual species. Without further illustrating the necessity of securing 

 birds at the present time suppose we look into the future centuries and we find a 

 subject of great interest requiring a mass of new material. I refer to differentiation 

 or modification. 



