282 
REPORT OF THE CHIEF OF ENGINEERS. 
Appendix L. 
ORNITHOLOGICAL REPORT FROM OBSERVATIONS AND COLLECTIONS MADE IN PORTIONS 
OF CALIFORNIA, NEVADA, AND OREGON, BY ASSISTANT II. W. HENSHAW. 
United States Engineer Office, 
Geographical Surveys West of the IOOtii Meridian, 
Washington, J). C., April 21, 1879. 
Sir: I have the honor to transmit the following report upon the ornithology of the 
regions visited by me during the field seasons of 1877 and 1878. 
Very respectfully, your obedient servant, 
3 II., W. Henshaw. 
Capt. George M. Wheeler, U. S. A., 
Corps of Engineers, in charge. 
The present report includes an enumeration of the birds met with during the field 
seasons of 1877 and 1878 by the writer, with more or less extended notices of their 
habits, relative abundance' or scarcity, extent of habitat, &c., &c., from original field- 
notes and observations. To but a limited extent has it been thought advisable to de¬ 
part from the rule of including only results accruing directly from the expedition, and 
to indicate briefly general facts respecting the distribution of species elsewhere, as com¬ 
pared with the region under consideration. In the instance of a number of the puz¬ 
zling forms met with, a careful study has been made of their relations with allied 
species and the results included in the present connection ; but in the main the notes 
bear directly upon the area included in the examinations of the survey for the time 
specified. 
In 1877, field-work in connection with Party No. 1, California Section, extended from 
the 12th of May to the 1st of October. The following year and with the same party, 
the interval between July 18 and October 1 constituted the field season. Unfortu¬ 
nately in the latter year work began at so late date that the much desired opportunity 
was lost of presenting in the present report a full account of the very considerable 
number of species inhabiting this region, of whose nesting habits little or nothing is 
known. The notes therefore that bear upon this part of the birds’ histories were ob¬ 
tained during the early portion of but a single season. 
The routes followed during the two years amounted practically to a continuous line 
from Carson, near the western border of Nevada and a little south of the Central Pa¬ 
cific Railroad, to The Dalles, on the Columbia River. A considerable portion of the 
time was spent in the mountains, but more in the valleys and on the plains that lie 
at their eastern bases. Thus opportunity was had, so far as the necessities of the 
topographical parties to which the writer has usually been attached would permit, 
to make a comparative study of the birds of the several sections entered. Taken in 
connection with what has hitherto been accomplished in the same region, and espec¬ 
ially with the very valuable report of Dr. J. C. Newberry, made in 1855, it is thought 
that the avifauna of the eastern slope, in its general features, may be considered as 
pretty well made out. Perhaps a brief glance at the area covered in the present report, 
in its relations to contiguous regions, may be of interest. 
The Sierra Nevada of California, in its entire length, and the Cascade Mountains of 
Oregon form essentially a continuous chain of. peaks, which constitutes the first real 
obstacle to the extension of animals and plants to the westward that is encountered 
after the main chain of the Rocky Mountains, the “backbone” of the continent, has 
been passed. So far, at least, as the extension of birds is concerned, it appears to be 
an extremely effectual one, and the rockji barrier thus constituted maybe taken as 
limiting with precision the Middle Faunal Province. 
Attention has elsewhere* been called to the fact that the influence of the Pacific 
province is visible in the birds of the eastern slope, and the conclusion drawn from a 
study of its avian life, that, while by no means a typical portion of that province, it is 
yet sufficiently dashed by Pacific province forms as to more properly be included in 
that zoological division rather than with the middle region. The number of species 
and varieties of birds typically representing the Pacific province that are found along 
the eastern slope is not very great, since, of course, they are limited to mountain-in^ 
habiting forms that constitute but a small proportion'of the aggregate number be- 
longing thereto. On the other hand I know of but four species strictly attributable to 
the middle region that reach into the mountains of the eastern slope, viz, Tardus pallasi 
audnboni, Carpodacus cassini, Pica melanoleuca hudsonica, and Tetrao ohscuriis. That the 
* Annual Report of Geographical Surveys West of the One Hundredth Meridian, 1877, p. 1304 \etseq. 
