18 University of California Publications in Zoology. |Vou.5 
Santa Ana. The north base of Sugarloaf merges into the gentle 
slope leading down to Baldwin lake, at about 7500 feet altitude. 
This gentle slope is a typical sage flat. The hills to the east are 
largely upper Sonoran in spite of the high altitude; for this is 
on the side influenced by the desert air currents, and shut off 
from the cooling Pacific breezes. It is a very arid region, too. 
A small stream gushes out at the upper end of the sage flat, and 
a cienaga of a few acres relieves the saginess along its course ; 
but it shortly soaks away. I found only one spring (in August) 
on the north side of Sugarloaf, in the deepest canon on the east 
side. There are as many belts of plant life on the north face of 
Sugarloaf, an altitudinal distance of only 2300 feet, as there are 
on the north side of San Bernardino peak in 6000 feet. In a 
mornine’s climb up the former I passed from the sage and pinon 
(Upper Sonoran), into black oak and yellow pine (Lower Trans- 
ition) ; then through silver firs (Upper Transition), into the pure 
tamarack pine woods of the Boreal zone. On the crest of the 
ridge are a good many limber pines, which might be considered 
an indication of the middle division of Boreal (Hudsonian). 
My visit to this interesting region was too late in the season to 
be at all sure that the birds were in their breeding zones. In 
fact, they had very evidently moved up and down, and many 
migrants were also in evidence. On August 22, 1905, in the one 
hour from 10 to 11 a.m., I hid myself in a willow thicket near 
the spring at 8500 feet altitude on the north side of Sugarloaf, 
and took a census of all the birds visiting the spring during that 
time. Highty-five individuals were noted, representing the fol- 
lowing species: four red-shafted flickers, two Cabanis woodpeck- 
ers, one Clarke nutcracker, three blue-fronted jays, two Allen 
hummingbirds, two Stephens fox sparrows, three green-tailed 
towhees, twenty-five Sierra juneos, twenty-five Audubon warblers, 
one slender-billed nuthateh, six mountain chickadees, six Iutes- 
cent warblers, two Parkman wrens, two golden pileolated war- 
blers, and one Tolmie warbler. 
Towards the north base of the mountain and out on the flat, 
mixed with the sage, were extensive thickets of service-berry 
bushes, loaded with ripening fruit. Here birds from all direc- 
tions fairly swarmed, and to enumerate them here would be to 
