As the females and autumn birds almost invariably retain suggestions of 

 the characteristic spring markings of the males the difficulty is really less 

 than is generally anticipated. Of course, puzzling specimens occur which 

 give even the experts some difficulty, but it is usually an alternative between 

 two species, which can be settled by giving attention to one or more 

 small details. In studying the warblers the observer is advised to first 

 become familiar with the spring males. When the males of the common 

 species are known, a comparatively easy matter with such strongly char- 

 acterized forms, most of the females are recognized without much difficulty 

 as they usually carry a subdued reflection of their mate's brighter colour 

 pattern. In the autumn, most juveniles resemble the females closely 

 enough to make recognition not so very difficult. There are thus compara- 

 tively few plumages besides the spring males that have to be learned 

 individually. The Canadian Warblers represent twelve genera, seven of 

 which are represented by single species only. Dendroica has sixteen species, 

 Vermivora five, and three others are represented by three species each. 

 The generic details of the most important will be discussed under their 

 proper headings. 



Though called "Warblers" their song should as a rule hardly be 

 dignified by such a term. With few exceptions the songs are only insig- 

 nificant little notes without much prolonged continuity, but as they are 

 often specifically distinctive the student is advised to pay close attention 

 to them, for when the great warbler migrations are on, the presence of a 

 new or rare species is often first made known by a single unfamiliar sound 

 directing attention from the many to the one that would otherwise escape 

 notice. 



Economic Status. The Warblers are highly insectivorous. A few 

 take more or less seed and a little fruit, the latter almost invariably wild, 

 and no complaints have been made against any of the family. Their 

 effect, therefore, is wholly beneficial. Being active they reach all kinds of 

 insect habitats from the axils of highest flung leaves to between blades of 

 grass on the ground, and as they are small they are satisfied to take insects 

 and insect eggs that are too insignificant or too well hidden to receive the 

 attention of larger birds. 



636. Black and White Warbler. BLACK AND WHITE CREEPER. FR. LA FAUVETTE 

 NOIRE ET BLANCHE. Mniotilta varia. L, 5-30. Plate XXXIX B. There is little 

 plumage variation. 



Distinctions. A small black and white warbler which creeps about holes and branches 

 like a woodpecker. In the autumn the colours of the young bird are similar to those of 

 the adult but slightly veiled and have small washes of buff and less black on the throat. 

 It is only to be mistaken in spring for the Black-poll but the white median stripe on the 

 crown instead of all black can distinguish it from that species. 



Field Marks. Its creeping habits, strong black and white coloration with median 

 crown stripe. In the autumn it is the only all black and white warbler to be seen in eastern 

 Canada. 



Nesting. On ground -at the base of a stump, log, or rock, in nest of strips of bark, 

 grasses, etc., lined with rootlets and long hair. 



Distribution. Eastern North America; breeds in most of Canada north to well beyond 

 the settlements. 



This is one of the earliest warblers to arrive "in the spring and one of 

 the easiest to identify at any time as it is always well marked and there is 

 little difference in seasonal or sexual coloration. 



