368 ANIMAL LIFE IN THE YO SEMITE 



Canon, 9600 feet (July 19, 1915). Present on floor of Yosemite Valley, at least in 

 spring. Noted during spring migration at Dudley, April 29, 1916 (D. D. McLean coll.), 

 and at Pleasant Valley, May 24, 1915. Inhabits brush patches, foraging and singing 

 from perches above these and less often from limbs 10 to 30 feet above ground in 

 adjacent trees. 



The Wright Flycatcher is one of a group of small flycatchers (genus 

 Empidonax), the members of which are so closely similar in size and 

 coloration that they cannot always be distinguished from one another in 

 life on these characters alone, even by an expert. Fortunately, some of 

 the species in this assemblage possess distinctive call notes by which they 

 may be recognized; and each of them occupies a particular habitat or 

 type of country, so that as a rule they may be identified upon the basis 

 of these life characteristics with a fair degree of certainty. Thus the 

 Wright Flycatcher is characterized by the lisping quality of its rather 

 protracted song (described in detail farther on), and by its preference 

 for the chaparral slopes of the higher altitudes (mostly above 6000 feet). 



The earliest seasonal record we made for the Wright Flycatcher in 

 the Yosemite region is for April 29, 1916, when an adult male was collected 

 near Williams Butte, east of the mountains. AVhen we arrived at Hazel 

 Green, on May 14, 1919, these flycatchers were already present ; by May 17, 

 in the same year, males had established posts in Yosemite Valley, and 

 by May 19, at Chinquapin. The species probably arrives in the Yosemite 

 region in numbers during late April or early May. Through the summer 

 it is common within its proper range, which extends to greater altitudes 

 than that of any of the other members of the group. After the young 

 are reared the birds indulge in a slight up-mountain movement to still 

 higher levels, even to timber line, in an endeavor to profit by the increased 

 food supply then available there. The latest record of this bird at hand is 

 for September 13, 1915, when 5 were seen and 2 collected for positive identi- 

 fication, at Gem Lake (altitude 9036 feet). The 5 birds were in willows, 

 a habitat not usually frequented by the Wright Flycatcher during the 

 summer season. This of course marked them as transients; for it is well 

 known that many species of birds during migration forage or seek shelter 

 in situations totally different from those which they customarily occupy 

 during the nesting season. 



At Chinquapin, on May 21, 1919, a pair of Wright Flycatchers was 

 found exercising squatter's rights over about an acre of dense chaparral 

 on a flat near the stage barns. The thicket was about four feet high and 

 comprised a dense growth of snowbush {Ceanotkus cordulatus), green 

 manzanita, and chinquapin. The male bird had a number of forage posts 

 at the tops of some dwarfed black oaks which struggled up slightly above 

 the general level of the chaparral ; he would progress from one to another 



