Nov., 1921 HOME LIFE OF THE BLACK-TAILED GNATCATCHER 177 
eatechers. In the ease of the pair nesting in 1920 the male invariably followed 
the female from bush to bush while hunting together. This female was nota- 
ble for the decidedly brown tone of the back and wings, contrasting with the 
clear gray of the male. The male whose photographs appear herewith showed 
at all times an independent and fearless disposition. His mate, after each 
brood was hatched, at first refused to visit the nest while a person was near, 
but soon gained confidence. Under other circumstances she occasionally in- 
dicated marked curiosity by approaching silently to within arm’s length or 
hovering close above one’s head. 
It does not seem to be generally known that the black cap of the male 
Black-tailed Gnateatcher is present only in spring and summer plumage. Hav- 
Fig. 31. a, MALE BLACK-TAILED GNATCATCHER SHADING YOUNG FROM SUN; 
ILLUMINATED BY REFLECTED LIGHT; PHOTO TAKEN JUNE 30, 1921. b, 
MALE BUACK-TAILED GNATCATCHER; PHOTOGRAPHED May 13, 1921. 
ing previously noticed the absence of black-capped birds during the fall and 
winter months, I was able, by systematically watching the male here shown, 
to observe the changes in the color of the cap. About the middle of February 
black patches appeared on the crown and quickly spread over the entire top 
of the head. The reverse change in the fall took place much more slowly and 
in the form of a gradual obscuring and replacing of the glossy black by gray. 
The first signs of gray could be detected about the middle of July and it re- 
quired approximately a month and a half for all traces of darker color, with 
the exception of a permanent blackish streak above the eye, to disappear. 
The change appeared to be complete before the new tail feathers were entirely 
