GEOGRAPHICAL SURVEYS WEST OF 100TH MERIDIAN. 301 
By the above, however, it is by no means intended to imply that snch matters are 
not entitled to a place as aids to the proper understanding of the relation of species 
to each other. It is doubtless true that there is occasionally to be noticed certain 
changes in respect to the habits and songs of birds that accompany changes of locality, 
and which may furnish the first clew to external variation, in support of which they 
may be adduced as additional and valid testimony. But it is no less true that the 
purely individual variation in birds’ songs and habits is often very great; in truth, 
such appears to be the rule rather than, the exceptiou ; a fact which should be kept 
fully in mind when such features are made to enter into the question of specific or 
varietal distinctions. 
P. chlorurua (Towns.) Green-tailed Finch. 
This sparrow is rather numerous in summer along the eastern slope, and reaches 
well into Oregon, if not, indeed, to the Columbia River. 
Several nests with eggs were found in July. 
ALAUDID.E—Larks. 
Eremophila Boie. 
E. alpestris chrysolcema (?) (Wagl.). Horned Lark. 
The usual central region form of the horned lark occurs rather numerously about 
Carson in summer upon barren pasture lauds, sage brush, and alkaline flats, &c. Its 
breeding rauge extends into Southern Oregon, and perhaps even farther northward. 
It appears to me that the identity of this central region form with the chrysohema 
of Mexico is open to doubt and that its true place may be elsewhere. Pending an ex¬ 
amination of the question, however, I employ the name in current use. 
ICTERIDJE—Orioles. 
Xanthocephalus Bonaparte. 
X. icterocephalus (Bp.). Yellow-headed Blackbird. 
This blackbird is extremely abundant in all suitable localities along the eastern 
slope far towards the Columbia River. In the latitude of Carson, it begins to breed 
somewhat before the middle of May, and by the 15th the tule beds, to which it 
always resorts, will be found to contain nests in all phases of construction, while a 
few pairs, more ardent or enterprising than the rest, possess their full complement of 
four eggs. By the 1st of Juue nearly every nest contained eggs in various stages of 
advancement, while in not a few instances the young had already made their appear¬ 
ance. 
The habit of colonization at this period is carried in this species to an extreme not 
observable in any other of the family, unless, perhaps, it be the tri-colored, as that 
bird is found in Southern California. Thousands flock together to form a happy, noisy 
community, their songs filling the swampy recesses with a confused and indescribable 
medley. Though by no means melody of a high order, they fall not unpleasantly upon 
the ear rightly attuned to bird music, when they are correctly interpreted as a mere 
rendering into audible sound of the overflowing jollity and good humor of the birds 
as they trill forth the notes in a happy-go-lucky sort of style from the swaying reeds. 
The nests, while usually built well up on the reeds and fastened to the upper 
stalks, are not always so situated, but are occasionally, as was noticed in several in¬ 
stances at Washoe Lake, placed close to the marshy ground among the coarse grasses. 
When such is the case, the structure is very similar to that of the common red-wing 
under like circumstances. As the nests so placed were among the earliest found, it is 
probable that the more usual positions—high up on the reeds—is exchanged for one 
affording better protection and security for the early broods. 
Dr. Coues tells us that the males appear to desert the females during the period of 
incubation. But if this be a matter of observation, I think it is, to say the least, un¬ 
usual. I have found the males of this species as domestic in their habits and as assidu¬ 
ous in attention to their young as any of the family. It is true, as observed by Mr. Nel¬ 
son, that they are much shyer than their mates, the natural result of their more con¬ 
spicuous colors and their distrust of danger on account of this. They are hence less 
often seen about the nest when it is disturbed. 
Agel.eus Vieillot. 
A. pliceniceus (L.). Red-winged Blackbird. 
An abundant summer resident along the eastern slope. 
Carson. 
More or less winter about 
