150 University of Calif orma Publications in Zoology ["^ol- 24 



in northern Alberta, to the eastward. The adjacent coastal strip of 

 southeastern Alaska is indicated as Canadian, and there are narrow- 

 strips of Canadian extending inland along certain river valleys, of 

 which the Stikine is one. The interior is thus regarded as of a higher 

 zone than the coast. This is not in accordance with our own findings. 

 One of the rules upon which life zones are based is as follows : ' ' The 

 northward distribution of terrestrial animals and plants is governed 

 by the sum of the positive temperatures for the entire season of growth 

 and reproduction" (Merriam, 1898, p. 54). Exact figures are lacking 

 for the region we visited, but there can be no doubt that the summer 

 temperature of the country immediately east of the mountains is 

 appreciably higher than on the coast. In further illustration of the 

 relative zonal positions of the two regions, the following lists of some 

 characteristic summer birds of the lowlands should be considered. 



COAST INTERIOE 



Dendragapus obscurus sitkensis Bonasa umbellus iimbelloicles 



Oyanooitta stelleri stelleri Buteo swainsoni 



Nannus hiemalis pacifieus Nuttallornis borealis 



BegiJus satrapa olivaceus Spizella passerina passerina 



EegTilus calendula grinnelU Vireosylva gilva swainsoni 



Ixoreus naevius naevius Setophaga rutiedlla 



Furthermore, in the course of our work the interesting fact was 

 developed that certain species of birds that occur commonly at sea 

 level on the coast occur inland at constantly increasing elevations. 

 Ascending the Stikine it is noticeable, at a point about a hundred miles 

 inland, that the characteristic spruce forest found at sea level on the 

 coast and on the banks along the lower reaches of the river, here begins 

 to ascend the mountain sides, its f)lace in the valley being taken by the 

 poplar woods. In the Telegraph Creek region we found the spruce 

 belt at an altitude of perhaps 1500 to 2000 feet, and found therein the 

 bird species to which reference is made. It is an additional complica- 

 tion that whereas certain subspecies extend unchanged from the coast 

 to the interior as inhabitants of this spruce belt, some species are repre- 

 sented by different subspecies, at the two extremes. Nannus hiemalis 

 pacifieus and Begulus satrapa olivaceus belong in the first mentioned 

 category. In the second, Dendragapus obscurus sitkensis, Begulus 

 calendula grinnelU, and Ixoreus naevius naevius, of the coast, appear 

 to be replaced in the interior by Dendragapus obscurus flemingi, 

 Begulus calendula calendula, and Ixoreus naevius meruloides. Among 

 mammals, Marmota caligata is one conspicuous species that occurs at 

 sea level on the coast {M. c. caligata) and at high elevations inland 

 {M. c. oxytona). It is a matter for regret that we were unable to give 



