IjSTTEODUCTION. 



25 



diminish in size until they reach their limit on the coast about opposite Kadiak Island, This large 

 island is included within the present district, and forms its western boundary. Strangely enough, 

 although the eastern part of Kadiak is heavily wooded, the western part of the island is destitute 

 of trees. The climate is somewhat drier and the winters colder in the Kadiak portion than else- 

 where in the district. 



The forests are almost wholly coniferous, and the Abies sitkensis, A. mertensiana, A. canadensis, 

 and Pinvs eontorta are generally distributed and form the great bulk of the trees. In the region 

 about Sitka and southward, the yellow cedar, Gupressus nutTcatensis, is a striking and handsome 

 tree of great size, reaching 100 or more feet in height and 5 or 6 feet through at the base. 



Taking the climate of Sitka as typical of this district, and bearing in mind that it becomes 

 milder to the south and drier and colder to the north and west, we have, as the results of nearly 

 fifty years' observations by the Russians, the following data : The maximum temperature during 

 this period was + 87°, with a minimum of — 4°, the mean annual temperature being 430.28. The 

 mean annual rainfall during this period was over ?0 inches, with the record for one year reaching 

 103 inches. The mean annual number of days on which rain and snow fell was 198, and it varies 

 from 190 to 285, according to Mr. W. H. Dall. 



To show the seasonal distribution of these factors I subjoin a table giving means for observa- 

 tions taken at Sitka during fourteen years between 1849 and 1862, inclusive: 



INOTB. — All of the temperatures in this report are according to Fahrenheit. 



The enormous precipitation upon the seaward face of the mountains along this coast has pro- 

 duced a large series of some of the finest glaciers in the world, which extend to the sea in many 

 of the bays. The effect of this damp climate and heavily-wooded region upon the animal life 

 found there is so well known, as illustrated on the coast of Washington and Oregon, that it scarcely 

 needs mention here. All of the colors of the birds and mammals resident here are intensified and 

 are darker than those shown by the same or allied species resident elsewhere. Pale browns be- 

 come rich rufous, or rusty-red, and grays become dark brown, with corresponding changes in other 

 colors. The red on Pinieola enucleator and Acanthis Knaria, in resident examples, is more Intense ; 

 enough so to nearly produce recognizable races. 



It is a well-known fact to fur traders that the furs of animals killed in this district are much 

 darker or more intensely colored than elsewhere in the Territory. This holds good with both cin- 

 namon and black bears, besides other species. 



Seiurus M^sonius douglassi is the most familiar and striking example of this intensity of col- 

 oration. Spermophilus empetra Icodiacensis, described from Kadiak specimens and not known from 

 other parts of the Territory, has the top of the head and middle of the back a much darker shade 

 of brown than is exhibited by typical empetra, which occupies most of the surrounding region. 

 Curiously enough, liodiacensis exhibits, at the same time, a much paler or grayer color on the 

 sides and below than is shown by empetra. 



Among the birds of this district the effects of climatic influence are even more marked than 

 among the mammals. In the following list are named the species showing this most plainly : 

 Turdus aonalaschJcm, T. ustulatus, Parus rufescens, Troglodytes Jticmalis pacificiis, Leucosticte 

 tephrocotis littoralis, Melospiza fasciata rvjina, Passerella iliaca unalaschensis, Cyanocitta stelleri, 

 Megascops asio Icennicottii, Bubo virginianus saturatus, Accipiter atricapilius striatulus, Den- 

 dragapvs obscurus fuliginosns, Bonasa timbellus sabini, with Acanthis linaria and Pinieola enucleator, 

 in which the intensification of color is apparent but not sufficient to warrant separation from the 

 typical form. In addition to the foregoing species the following birds are only found in the Sitkai^ 



S. Mis. 156 4 



