LITTLE FLYCATCHER 203 



seems to have any effect on the frequency or the strength of the 

 flycatcher's notes. 



"In midsummer, after the little flycatcher's nesting time is over, 

 and when many of the other birds are silent, its notes will still be 

 heard almost each day, though more so near the close, also occasion- 

 ally after sunset; and this is the case until well into August, after 

 which they wholly cease." 



Mr. Howsley contributes the following notes : "During the earlier 

 mating period, it is common for this flycatcher to give the pre-pe-dee 

 call, not pre-pe-deer like the western flycatcher, but a short, snappy, 

 dead tonal sound. Later, this note changes to zwee-beck, just as 

 short and snappy. This call is given altogether after mating has 

 been completed and nesting begun, the pre-pe-dee not being heard 

 afterward. In the earlier stages of courtship, several birds were 

 heard to mix the two calls, sometimes using one, sometimes the 

 other." 



Field marks. — As stated in this paragraph under the other species, 

 the four common, western Empidonaces are difficult to recognize in 

 life by color or markings; they have no prominent field marks, 

 though, as Dawson (Dawson and Bowles, 1909) says, "comparing 

 colors, Traill's gives an impression of brownness, where the Western is 

 yellowish green, Hammond's blackish, and Wright's grayish dusky. 

 These distinctions are not glaring, but they obtain roughly afield, in 

 a group where every floating mote of difference is gladly welcomed." 

 The notes of the four species are quite distinctive, and they are 

 commonly found in quite different types of habitat. None of the 

 other three is likely to be seen in the low, dense, moist thickets fre- 

 quented by the little flycatcher. 



Enemies. — Both subspecies of Empidonax trailli are rather un- 

 common victims of the cowbirds of their respective regions, except 

 in southern California and Colorado. Dr. Friedmann (1929) says: 

 "Forty records have come to my attention, two from Colorado, and 

 the rest from California." 



Winter. — The fall migration must start very early in August, for 

 Dickey and van Rossem (1938) say: 



The first fall arrivals of this species appeared August 14, 1925, In the flooded 

 forest at Lake Olomega [in El Salvador], and within a few days it became 

 extremely common all through the undergrowth. By far the greater part were 

 of the western subspecies, breivsteri. During the winter Traill's flycatchers 

 were fully as abundant as during the fall, and as many as fifty were seen in 

 one day in the willows and shrubbery along the San Miguel River. Out of 

 four specimens taken at random in that locality on February 3, 1927, three were 

 brewsteri and only one was trailUi. Between April 1 and 12, 1927, during the 

 spring migration, these flycatchers were literally swarming in the underbrush 

 of the sandy peninsula at Barra de Santiago. Three specimens taken were all 

 breivsteri. 



