KEYS 



Note. — The following signs and abbreviations are used in the keys and 

 in the text : — 



$ — male. 

 ? = female. 

 Ad. = adult. 



Im. = immature. 



* = irregular. 



** = very irregular. 



Groups A (birds larger than an English Sparrow) and B (birds smaller 

 than an English Sparrow) may be used throughout New England and 

 eastern New York; groups A' and B' only in southern Connecticut and the 

 lower Hudson Valley; groups A" and B" onh r in the northern portions of 

 New York and New England. (See p. 25.) 



No provision has been made in the keys for birds in immature plumage; 

 in the autumn and winter in most cases where the female (?) is specified, 

 young males may be included in the same category. 



The occasional dates of arrival or departure given in the keys are, of 

 course, only approximate, and will vary according to the season and to 

 latitude. One may also expect a variation of about ten per cent, each way 

 in the lengths of birds given in the keys and text. 



