Nov., 1901. I 
THE CONDOR 
165 
Contopus borealis. Olive-sided Flycatcher. A common species all through 
the Sierras, its shrill notes from the tall, dead trees marking its presence every- 
where. The birds are very cautious after nesting has commenced and its requires 
vigilance to detect either bird at the nest. The male will sit in one place seldom 
varying its monotonous note for even an hour at a time, if it finds it is observed, 
and now and then a low chuckle from the female on her nest is the only response. 
PHOTOGRAPHING AN OLfVE-SIOED FLYCATCHER'S NEST 70 FEET UP IN SILVER FIR. 
but too ventriloquistic to expose the location of the nest. The nests are completed 
at Fyffe by June i and contain fresh eggs until about the middle of June. I 
collected a nest on June 10 1897 from a fir tree, the nest being 72 feet from the 
ground on a horizontal limb. The nest was composed of rootlets with which was 
mixed a quantity of a bright yellow dry moss {^Evernia vulpina') so common in the 
Sierras, and contained four eggs, one third incubated. This nest afforded an 
opportunity to attempt aerial photography with fair results. The birds were very 
pugnacious while I was in the tree, flying about with a lively snapping of beaks. 
June 14, 1897 Mr. Carriger found a nest in a Douglas spruce 72 feet up. This 
contained four eggs, but owing to the droop of the limb and the distance of the 
nest from the trunk of the tree it could not be reached. A scoop was tried but 
efforts to secure the eggs proved unsuccessful. The average heights of nests f)f 
