164 THE CONDOR | (Vol. Seem 
an open pasture. Although the tree was fairly thick, the nest was deserted be- 
fore an egg was laid. Whether due to my having discovered it, or the result of 
its position, I have no way of telling. I discovered the nest at a distance of 
about twenty feet from the tree and did not approach any closer until I re- 
turned for the set, when I found the nest deserted. 
The nest is placed from seven to twenty-five feet up, and well out at the 
end of a branch, usually very well concealed. As a matter of fact unless dis- 
covered building the nest is almost impossible to locate. On one oceasion | dis- 
covered a nest by the fact that its occupant, presumably the male, was singing 
while on the nest. I judge this to be a rather uncommon occurrence. The nest 
blends so well with its surroundings that sometimes, even though | have for- 
merly located the nest, I have had difficulty in locating it again. 
It might be well here to describe one or two nesting sites, to give a fair 
idea of their normal location. I found one nest, March 13, 1918, by following 
the building birds. It was located in a small live oak tree about seven feet 
from the ground. It would have been impossible to have seen it from any angle 
except directly above, unless led to it by the birds. Fronds of Spanish moss 
hung all about it, part of one frond being woven into one side of the nest. The 
nest was on the west side of the tree. Another nest, more usual in location, I 
found on March 8, 1918, It was about sixteen feet from the ground and about 
the same distance out from the trunk, near the end of a large branch in a elus- 
ter of folhage and moss. An unusual nest was one located in a manzanita bush 
under a live oak. This nest gave my companion and me a bad hour or two be- 
fore we located it; we must have passed by it at least three times before it was 
discovered. This is the only instance that has come under my observation, oi 
the bird building in other than a live oak. 
The usual complement of eggs is four, sometimes three, very Seldom five. 
I believe Mr. H. W. Carriger has one set of five taken by Mr. Gurnie Wells in 
Sonoma County. This is the only set of five I have heard of. The ground color 
of the egg is pearly white, dotted with reddish brown spots and specks at the 
larger end. The ground color never varies, but the number and distribution of 
the spots is seldom alike in any two eggs. In one set of three in my collection, 
one egg is pure white with very few minute specks on it; the other two have 
only a few slight markings. In most of the other sets I have, the markings are 
typical. The eggs vary somewhat in shape and size, some sets being slightly 
round without being distinctly larger at one end than the other, while others 
are elongated and larger. 
About two weeks after incubation is started the nestlings are hatched and 
by the time the month is out they are ready to take their first trials of flight. 
The nestlings are fed by both parents during ther stay in the nest. I watched 
four fledglings being fed for a period of about an hour; they were visited every 
rive minutes on an average during this period. The nestlings were partially 
covered with feathers at the time and were keeping the parents very busy fill- 
ing their hungry mouths. 
T have given some study to bird population in this territory and estima. te. 
that in associationally good country a hundred breeding pairs to the square | 
mile is a fair average. The area of Sonoma County is fifteen hundred square — 
miles, and of that area about two hundred and fifty are well sprinkled with — 
live eas This would give about twenty-five thousand breeding pairs of Hut- 
ton Vireos in Sonoma County. I consider this really to be a low estimate. Here 
