207 



Field Marks. The even and uniform bright yellow of spring birds is unmistakable. 

 Some dull females are more green than yellow but the green-edged wings and yellow 

 tail, lack of colour contrasts, size, and actions of the bird are easily recognized. 



Nesting. In an upright crotch in bushes and small trees in nest of fine fibres and a 

 large amount of plant-down, lined with plant-down and sometimes long hairs. 



The Yellow Warbler is one of the few species that sometimes refuses to incubate 

 Cowbird's eggs. Instead of throwing out the intruding egg, however, it builds a new 

 nest over the old one, burying it and its entire contents, including often some of its own 

 eggs, in the foundation of the new structure, in which another set of eggs is deposited. 



Distribution. Nearly all North America. The Eastern Yellow Warbler inhabits 

 all Canada except the Pacific slope. 



SUBSPECIES. The Yellow Warbler is divided into four subspecies; the Eastern 

 Yellow Warbler D. cestiva which occupies most of Canada, includes the type of the species. 



This is the commonest breeding Warbler in southern Canada. It 

 shares with the Goldfinch the popular name of Wild Canary, but the lack 

 of black will determine it at a glance. It is found in shrubby localities in 

 open country or along stream or marsh edges. It is a common visitor to 

 the garden and its cheery little song is very pleasing. In the autumn the 

 Yellow Warbler is one of the first species to leave. Shortly after July 

 it disappears and by mid-August only a few stragglers are left. It goes 

 before many observers begin to think of autumn migrations and thus 

 details of its autumn movements are difficult to obtain. 



654. Black-throated Blue Warbler. FR. LA FATJVETTE BLEUE 1 GORGE NOIRE. 



Dendroica caerulescens. L, 5-28. Plate XL B. 



Distinctions. The male, so descriptively named and strongly marked, is very dis- 

 tinctive. The female, however, especially in autumn, is more difficult to distinguish; 

 it may resemble either the juvenile of the Tennessee, the autumn Black-poll, or the Bay- 

 breast. The streaked back and wing-bars, however, of the two last are absent. It 

 is darker and more greyish green than the Tennessee above and more buffy below. An 

 indistinct and partly concealed white or light spot at the base of the primaries is always 

 diagnostic of females of this species. 



Field Marks. The male is distinctive. The female in any plumage can usually 

 be recognized from all other evenly coloured dull green warblers by the sometimes very 

 faint light spot at the base of the primaries, which shows more conspicuously in life 

 than might be expected. 



Distribution. Eastern North America, breeding in the north, south to the borders 

 of civilization. 



SUBSPECIES. The Black-throated Blue Warbler is divided into two subspecies 

 of which we have only one in Canada, the type form D. c. caerulescens, the Northern Black- 

 throated, though occasionally specimens closely approach the southern variety, Cairn's 

 Warbler D. c. cairnsi, in having a suggestion of black spots on the back. 



655. Myrtle Warbler. YELLOW-BUMPED WARBLER. FR. LA FATJVETTE A. CROU- 

 PION JAUNE. Dendroica cor onata. L, 5-65. Plate XLI A. 



Distinctions. A very easily recognized species. All plumages have at least sugges- 

 tions of the yellow crown, rump, and side marks. The juveniles are largely rusty brown 

 above and have more or less of a wash of same colour across breast with the streaks only 

 slightly indicated. 



Field Marks. The yellow rump is always distinct and bright and makes the most 

 conspicuous field mark. Its presence and the side and crown marks of the same colour, 

 sometimes indistinct in autumn but always present, make reliable identification guides 

 in life. 



Nesting. In coniferous trees, 5 to 10 feet above the ground in nest of vegetable fibre 

 lined with grasses. 



Distribution. Nearly all North America north to tree limits. Breeding just beyond 

 the dense settlements. 



