410 U.S. NATIONAL MUSEUM BULLETIN 23 7 pabt i 



are in almost constant song and keep as far as possible from one 

 another. There is, thus, little overt aggression among them. 



Nesting. — This absence of territorial behavior, coupled with the 

 shyness of nesting birds, makes nest hunting difficult. The dis- 

 covery of fully fledged young redpolls in the streamside alders of 

 Indian House Lake on June 8 was a complete surprise to me. Six 

 occupied nests were found on June 9, 14, and 25. These nests were 

 bmlt on a careless foundation of small twigs laid across adjacent 

 branches out from the trunk of a small spruce, or in the crotch of an 

 alder or willow, and from 3 to 6 feet off the ground, usually about 

 5 feet. On this platform is woven a loose cup of fine twigs, rootlets, 

 and grasses or, if in the forest, black tree moss {Usnea harhatus). 

 The nest is then completed by a thick layer of ptarmigan body 

 feathers (mostly white), making a small warm cup into which the 

 female can sink almost out of sight as she sits on her small eggs. AU 

 these nests appeared to be loosely buUt, and they disintegrated 

 quickly once abandoned, their feather liniug blowing away. Walkin- 

 shaw (1948), on the other hand, considered the Alaska nests very well 

 bmlt, and found many of the past year's nests in the low leafless 

 willows. 



L. I. GrinneU and Ralph S. Palmer (Grinnell, 1943) had similar 

 difficulty locating nests around ChurchUl, Manitoba. Of nine nests 

 found, "the bulk material was chiefly dried grasses, though in one 

 nest, small twigs had also been used." Ptarmigan feathers were 

 used in the lining of eight nests, plant-down in five, hair in one, and 

 lemming fur in another. According to Brandt (1943), the use of 

 small twigs as a nest foundation is characteristic of this species and 

 helps to distinguish it from the nest of the hoary redpoU where the 

 two nest together in Alaska. 



The dimensions of 11 nests given by L. I. GrinneU (1943) and 

 Brandt (1943) were as follows: Outside diameter, 7.6 to 10.0 cm., 

 averaging 8.7; inside diameter, 4.5 to 6.0 cm., averaging 5.6; outside 

 depth, 5.0 to 8.8 cm., averaging 6.8; and inside depth, 3.0 to 5.1 cm., 

 averaging 4.0. 



The nest site naturally varies with the type of cover available. 

 In the semibarrens, the principal habitat of this species, it nests 

 usually in dwarfed or poorly formed spruces, or in willow and alder 

 thickets. Where the common redpoll ranges onto the tundra, it 

 must perforce use any cover available, whether driftwood stranded 

 by high tides, tufts of grass, or human artifacts. Concealment 

 likewise varies considerably; nests in spruce are usually the best 

 concealed, those in deciduous shrubs sometimes poorly so because 

 they may be built before the foliage has developed enough to provide 

 concealment. Although some nests survive the sweep of winter 



