ALASKA MYRTLE WARBLER 259 



breast in the male. The upper parts in winter plumage and in the 

 young are also less rufescent than in the eastern bird." 



The breeding range of this race, so far as known, extends from 

 northwestern Mackenzie to western Alaska, and southward to central 

 British Columbia and central Alberta. It has been found in winter 

 from California to southeastern Louisiana, in the southeastern United 

 States, and in northern Baja California and in southern Veracruz, 

 in Mexico. It may be commoner than is supposed, as it is recognizable 

 only with specimens in hand. 



Dr. Joseph Grinnell (1900) writes of its habits in northern Alaska: 



Hoover's Warblers were numerous summer residents of the timber tracts 

 throughout the Kowak Valley from the delta eastward. In the latter part of 

 August scattering companies were frequenting the spruce, birch and cotton- 

 woods, among the foliage of which they were constantly searching, with oft- 

 repeated 'chits,' just as are their habits in winter in California. The last ob- 

 served, a straggling flock of six or eight, were seen in a patch of tall willows 

 about sunset of August 30th. The following spring the arrival of Hoover's 

 Warblers was on May 22nd. They were already in pairs and the males were 

 in full song. At this season they were confined exclusively to the heavier 

 spruce woods. In the Kowak delta, on the 23rd of June, a set of five consider- 

 ably-incubated eggs was secured. The nest was in a small spruce in a tract of 

 larger growth, and only four feet above the ground. It is a rather loose structure 

 of fine dry grass-blades, lined with ptarmigan feathers. 



In the Atlin region of northern British Columbia, according to Mr. 

 Swarth (1926), it is a common species, breeding mostly in the low- 

 lands : 



A nest with five fresh eggs (Mus. Vert. Zool. no. 1992) was taken by Brooks 

 on June 15. It was in a slender spruce, one of a small thicket in a locality 

 that is largely poplar grown, about forty feet from the ground and near the 

 top of the tree. It rested on the twigs forming the terminal forks of a branch, 

 about three feet from the trunk. The outer walls of the nest were built mostly 

 of the shredded bark of the fire-weed stalks, with a little fire-weed 'cotton,' some 

 coarse grass and small twigs, and several wing and tail feathers of a small 

 bird. In the lining there was some horse hair, mountain sheep hair and a few 

 soft feathers. 



Another nest, containing newly hatched young on June 28, was in a small jack 

 pine in open woods on the shore of Lake Atlin. 



During the last week in August and the first week in September the southward 

 exodus was at its height. Flocks of warblers, mostly this species, flitted 

 rapidly through the poplar woods, and there was a constant stream of myrtle 

 warblers making long flights overhead. The last one, a single bird, was seen 

 September 19. 



As the breeding ranges of Hoover's warbler and Audubon's warbler 

 approach each other in British Columbia and may even overlap it 

 would not be strange if hybrids between these two closely related 

 species should occasionally turn up. Joseph Mailliard (1937) calls 

 attention to a number of such hybrids between both f onns of coronata 



