EASTERN WHITE-CROWNED SPARROW 1277 



and the shrub growth is still young. Under such conditions I have 

 found two nests only 300 feet apart, and computed territory sizes 

 as between .88 and 1.85 acres each. On the other hand, a breeding 

 bird census of 18 K acres of open lichen woodland— the most extensive 

 vegetative type of central Labrador — revealed a low density of two 

 nests, or about 1 territory per 9 acres. This would be about 70 

 pairs per square mile, but Thomas H. Manning (1949) estimated 

 that in western Ungava the population was between 10 and 30 pairs 

 per square mile, the higher counts being in burnt areas. 



Courtship. — The sexes being alike, it is difficult to follow territorial 

 disputes and courtship until birds have been color-marked. No one 

 has yet done this early enough in the season to unravel this phase 

 of the life history of the eastern subspecies. 



Within a week after arrival on the breeding grounds a good deal 

 of territorial song is heard from about 5:00 a.m. to 10:00 a.m. and 

 again in the evening. For a week or so thereafter the birds utter 

 much high-pitched trilling with depressed crowns, either from the 

 ground or from no more than 4 feet above it. This trill is quickly 

 communicated to the whole nearby group, several other birds then 

 repeating it. The trilling bird often attracts a companion who 

 approaches with crest high and loud pete notes, as though alarmed, 

 and they fly off together. Three-party nuptial chases are common 

 at this season. More specifically, the bird that emits the high, 

 trilling dreeeee note often crouches low, with head up, and flutters 

 its wings as though rotated from the "wrist." I did not notice the 

 tail-spreading and the spasmodic wing opening and closing that 

 caught the attention of Francis Harper (1958) in this same area. 

 As I proved by collecting, the female gives a loud chatter during these 

 mating chases (this female contained oocytes up to 1 millimeter in 

 diameter). Two weeks after the population arrived, while trilling 

 was going on everywhere, I saw a female crouch and trill (I wrote 

 whimper), and the male then mounted quickly three times. Soon 

 afterward song fell off noticeably. 



The male of the eastern white-crowned sparrow seems to share 

 some notes and postures heretofore (Nice, 1943, and Blanchard, 1936) 

 ascribed to the female only. On June 13, 1957, I collected a trilling, 

 wing-flipping bird that turned out to be a male. Error is easy under 

 the stress of collecting in close quarters, and a male that entered 

 unobserved may have been the inadvertent victim of my search during 

 the few seconds involved; but, again, on June 24, 1958, I saw a color- 

 banded male, the mate of a female with eggs in the nest, rotate its 

 wings "at the wrist," in the slow wing-flutter that the female gives 

 while trilling in invitation to copulation (Blanchard, 1936). 



