56 TJnwersity of California Publications in. Zoology [Vol. 3u 



Canada jays; the absence of these factors may have been the favorable 

 feature of the place. The nesting species of gulls and tern were not so 

 fortunate, for they suffered severely from the raids of herring gulls, to 

 the ultimate destruction of nearly all the young that were hatched. 



OTTEE CEEEK 



The upper portion of Otter Creek (3500 to 4000 feet altitude), 

 where we worked for two weeks, may be described as characteristic of 

 vast areas throughout this region that lie in an intermediate position 

 between the wooded lowlands such as border Lake Atlin and the 

 timberless mountain tops. Willow is the dominant forest growth 

 along the bottom of this valley, never as large trees but as densely 

 growing, rounded bushes, rarely more than twenty feet high and 

 usually much lower. On Otter Creek, as on some other streams, the 

 necessities of hydraulic mining have caused the damming of the stream 

 far up the valley. For miles above the lake thus formed the valley 

 floor is transformed into a willow swamp, a haven for ducks. 



The mountain slopes on either side, and much of the valley floor 

 in the upper reaches of the stream, are dry and more sparsely covered 

 with vegetation. There are extensive grassy areas, and at about 3800 

 feet altitude the creeping birch begins to be conspicuous. Mostly 

 this is a rather innocuous shrub, low-growing and easily walked over 

 or avoided, but I found some sections (at about 4000 feet altitude) 

 where it formed a chaparral on hill sides and ridges ten feet high or 

 more and well-nigh impenetrable. 



On the surrounding mountain sides, especially on north and east 

 facing slopes, spruce, and abo-fe that, balsam, grow in small groves in 

 some places, in solid stands for miles on favored exposures. On Spruce 

 Mountain, forming the western boundary of Otter Creek Valley, this 

 forest ceased abruptly between 4500 and 5000 feet altitude. Above 

 that boundary grassy slopes and ridges prevail, with a very little false 

 heather in places and a few scattered thickets of balsam. 



ZONAL AND FAUNAL POSITION OF THE ATLIN REGION 



Atlin occupies a position relative to the coast about the same as 

 Telegraph Creek, in the Stikine Valley, and Hazelton, in the Skeena 

 Valley, 150 miles and 375 miles to the southward, respectively. Both 

 of these places I had visited in previous years (see Swarth, 1922, 1924), 

 and comparisons between the regions naturally follow. Atlin Lake is at 



