Occasional Papers of the Museum of Zoology 1 5 



As found on islands at Tanana poplars thickly cover many- 

 acres with nearly a pure stand, the trunks often reaching a diameter 

 of eighteen inches or more. Under an old forest of this kind there 

 are many decaying limbs and logs, but there is little herbaceous 

 vegetation. Old trees of willow and scrub alders may often be 

 found in the forest; there are also numerous young paper birches 

 and white spruces, and it seems certain that the poplars will 

 eventually be replaced by the white spruce-paper birch type of 

 forest. 



Tracks of mice and shrews and of red fox were seen in a poplar 

 forest near Tanana in winter, but no trapping was carried on in 

 this habitat and no opportunity was found to study a well-developed 

 poplar forest in summer. However, a few records from Osgood 

 are available. The vertebrates of the habitat probably differ 

 little from those of the white spruce-paper birch forest. 



A grove of aspens, Populus treniuloides , was noted near timber- 

 line in a cove on the hills north of Tanana, and several isolated 

 trees were seen on the shores of a small lake near the head of the 

 north fork of the Kuskokwim. The species was also found on the 

 divide toward Lake Minchumina, some of the trees being fair 

 sized, but on the top of a wind-swept hill they occurred in a thick 

 growth of stunted shrubs not over two or three inches in diameter 

 and about ten feet tall. It is probable that aspens occur much 

 more frequently than these notes would indicate. No records of 

 vertebrates were secured from the aspens. 



White spruce-paper birch habitat and association: 



Canachites canadensis osgoodi. Alaska spruce grouse. Resident. 

 Bonasa umbellus yukonensis. Yukon ruffed grouse. Resident, breeding. 

 Buteo lagopus sancti-johannis. Rough-legged hawk. Summer, breeding 



(Osgood). 

 Aquila chrysaetos. Golden eagle. Summer. 

 Pandion haliaetus carolinensis. Fish hawk. Summer, breeding. 

 Bnho virginianus lagophonus. Northwestern horned owl. Resident. 

 Surnia ulula caparoch. Hawk owl. Resident. 

 Strepioccryle alcyon caurina. Western kingfisher. Summer. 



