BELL'S VIREO 259 



jurious. This will add about 11 percent, leaving about 16 percent of 

 the food of debatable import. As the small quantity of vegetable 

 matter eaten is of no economic significance it may be disregarded. 

 Ladybird beetles are about the only beneficial forms that the birds 

 take, and these are not consumed in very great numbers." 



Behavior. — Ordinarily Bell's vireo is a timid, shy, retiring little 

 bird, but when incubating, brooding, or feeding its young it shows 

 considerable fearlessness, coming freely to the nest even in the near 

 presence of an intruder ; it has somtimes been touched by the human 

 hand while bravely defending its eggs or young. The male is quite as 

 devoted as the female, and generally remains near his incubating mate, 

 singing joyously in the same bush or in one nearby. But, at other 

 times, this vireo is active and restless, disappearing into its leafy 

 retreats on the least alarm; it jumps and flits about in the bushes so 

 rapidly that it is difficult to catch a glimpse of it, though it may be 

 watching the observer from behind some sheltering foliage. Its 

 actions remind us of that other dweller in low shrubbery, the white- 

 eyed vireo. It is often found in similar thickets with the white-eye, 

 or with the black-capped vireo in Oklahoma or Texas, where the 

 ranges of these species overlap. As Pitelka and Koestner (1942) 

 say, "individuals are seldom seen above six or seven feet in shrubby 

 vegetation and their flights are usually made low over openings 

 between thicket patches." 



Voice. — Mrs. Nice (1931) writes: 



There is no music in the Bell Vireo's refrain, but it possesses a quaint charm 

 in its air of enthusiasm, in the rapid jumble of it all. It may be phrased 

 tvhillowhec, whillowhce, whe6; sometimes there are three whiUoiohees. Either 

 song may end with a rising or falling inflection. When the bird is thoroughly in 

 the mood, his rate is a song every 3 seconds, but this rapid pace is seldom kept 

 up as long as a minute, 15, 16 and 17 songs a minute being the highest numbers 

 I have recorded, while 8 or 12 are more commonly heard. As for hour records, 

 a nesting bird sang the following number of times: 32, 56, 57, 61, 70, 99, 131 

 and 254. These birds seem to sing all day long and all summer long, although 

 in August their zeal diminishes ; the last songs are heard from the 13th to 21st 

 of September. 



Unlike most birds the male sings a great deal in the home bush ; in the 9 hours 

 of observation 388 songs were given there and 417 elsewhere. He even sings 

 while sitting on the eggs. On June 22 during a 41 minute session of incubation, 

 the absurd little bird gave 30 songs. 



Elsewhere (1929) she noted, on September 6, 1925 : 



The Bell Vireo sings a little each morning. One day we saw him eating 

 berries of black alder, in the meantime singing his regular jiggledy jiggledy jee; 

 he also had a scolding kind of song — zip zip zip zip zip zip zee. Sometimes this 

 was preliminary to the ordinary song, sometimes not. * * ♦ 



The scold, dice chec chee dice, is the most expressive utterances, given by 

 both male and female. A sputtering spee spec, heard from the male during 

 nest building, appeared to be a courtiug note. The juvenile call note is a single. 



