Sept, 1914 
BIRD NOTES FROM THE SIERRA MADRE 
209 
food as well as the female. The wrens were the only other members that left 
the open spaces around the tree, and usually it was only the female, who 
seemed to do all the feeding. The male spent most of his time on a stub above 
the nest singing, occasionally making short excursions after food. The other 
four species spent most of their time around the tree itself ; the Chickadees in 
an untiring search for insects upon the trunk and on the fallen limbs and bark 
around the base ; the Bluebirds and Martins using the higher limbs as stations 
from which to pursue butterflies, etc. ; and the two Swifts taking the stump as 
a point to circle and dodge around in graceful flight. 
I noticed that the Swifts had a habit of suddenly darting straight down, 
as on the angle of a long V, and, making a half turn at the lowest point, shoot- 
ing up again, in an ascent of inconceivable rapidity. As this brings me back 
again to this interesting bird, I will confess that I am all at sea, as regards this 
particular instance of unusual nesting. To all appearances the nest which I 
examined, and which I had seen the Swifts enter a number of times (nine in 
all, to be exact), was typical of the Tree Swallow {Iridoprocne bicolor) of 
which I had previously noted several pairs upon the flats, but none around this 
particular stub. All of the time I was on the snag the Swifts would fly at me, 
keeping up an angry and protesting twittering; and after I had come down, 
first one and then the other would alight at the hole and either go inside, or 
would hang on the edge for awhile and then fly off again with more excited 
twitterings. When at rest the white wing patches were very noticeable and 
also the extra long narrow wings that were crossed scissor-fashion below the 
tail. As there was absolutely no question of identification in this case, the 
query presents itself, first, what causes had operated to force these birds to 
choose this unusual nesting site ? And secondly, was this nest entirely of their 
own making? I say entirely, because I saw one of the birds carry a piece of 
grass into the hole after I had left the tree. Or had they pre-empted a swal- 
low ’s nest, remodeling it to suit their own taste? Of one thing I am positive, 
there was no soft vegetable or gummy matter of any kind in the nest compo- 
sition (I lifted the nest up expressly to see), such as I have seen mentioned by 
all writers on the subject before. 
In answer to the first question, I can only note a few facts that may bear, 
upon the subject. In an area of eight or ten miles around the flats, there are 
very few cliffs that would fill the needs of these birds, those which are of any 
extent presenting few cracks or fissures that would serve as nesting sites. One 
exception of which I have knowledge is, or rather was, until the winter just 
passed (when a rock slide shaved it absolutely bare), a large broken mass of 
granite, high up on the slopes of Strawberry Peak (in the Big Tujuiiga Range) 
situated a short mile or so to the northwest of the extreme western edge of 
Barley Plats. Here in previous years I have observed numbers of the Swifts, 
during the breeding season, but the nature of the intervening country has pre- 
vented a closer investigation. 
One other place where I have noted them in the breeding season is on the 
back slopes of San Gabriel Peak near the headwaters of the West Fork of the 
San Gabriel River. In preceding years the species has been fairly abundant 
along the rocky walls of the canyons here, but this year they have evidently 
been driven from their usual haunts by the heavy blasting which has been done, 
incidental to driving a new trail through the canyon. If our birds were some 
that were accustomed to nest in either of the places mentioned, or if an earlier 
nest in some more legitimate site had been by some cause destroyed, it might 
