HABITS OF VIRGINIA'S WARBLER 223 



until 1864, when the present writer took a second example at Fort 

 Whipple, on the 15th of August; this was a young bird, very 

 likely bred in the vicinity. Shortly afterward, in 1869, Mr. Ridg- 

 way ascertained that the bird was abundant in the East Huin- 

 boldt and Wahsatch Mountains, where it was breeding in thick- 

 ets of scrub-oak. He found a nest containing four eggs, on the 

 9th of August, on the side of a ravine ; it was sunken in the 

 ground among the withered leaves, so that its brim was flush 

 with the surface, and measured 3J inches in diameter by 2 

 inches in depth. The material consisted of loosely interwoven 

 strips of the inner bark of the "mountain mahogany ", mixed 

 with grasses, mosses and slender rootlets, and lined with the 

 far of some small quadruped. According to Dr. Brewer's 

 measurements, the eggs were 0.64 long by 0.47 broad; the 

 ground-color, when fresh, was rosy white, and this was "pro- 

 fusely spotted with numerous small blotches and dots of pur- 

 plish-brown and lilac, forming a crown around the larger end". 

 Mr. 0. B. Aiken shortly afterward extended the known range 

 of the species to include the eastern foot-hills of the Rocky 

 Mountains in Colorado, where it breeds. This excellent ob- 

 server found it in various parts of the State, but especially 

 along the eastern base of the mountains, where, in its favor- 

 ite haunts, it sometimes outnumbers all the other Warblers put 

 together. It is a shy and timid species, generally darting, with 

 its sharp note of alarm, into its place of concealment when ap- 

 proached. In summer, it frequents the scrub of the hillsides, 

 at any elevation up to about 7,500 feet, but during the migra- 

 tions it is found indifferently in the pine forests and among the 

 cottonwoods and willows along the streams. "The male is 

 very musical during the nesting season ", says Mr. Aiken, " utter- 

 ing his sweet ditty continually as he skips through the bushes 

 in search of his morning repast ; or having satisfied his appe- 

 tite, he mounts to the top of some tree in the neighborhood of 

 his nest, and repeats at regular intervals a song of remarkable 

 fullness for a bird of such minute proportions. . . . No bird 

 with which I am acquainted conceals its nest more effectually 

 than this warbler. This is placed at the base of a tussock of 

 grass among the oak bushes, being sunk in a hollow scratched 

 in the earth, so that the rim of the nest is on a level with the 

 surface. The overhanging grass of the tussock hides all so 

 completely that the nest is only to be discovered by the most 

 careful and persistent search. About the first of June, five 

 white eggs, delicately speckled with reddish brown, are laid." 



