CERULEAN WARBLER 333 



and tail coverts is lacking; below there is more yellow and tlie side 

 streaks are obscure. The first nuptial plumage is acquired by a moult 

 limited chiefly to the head and throat which become bluer and whiter 

 respectively. Later plumages are brighter, but green always replaces 

 the blue of the male." 



Food. — No thorough study of the food of the cerulean warbler seems 

 to have been made, but it is known to be insectivorous, foraging among 

 the foliage, twigs, branches, and even on the trunks of trees. It is an 

 expert fly catcher, darting out into the air for flying insects. A. H. 

 Howell (1924) says that "examination of 4 stomachs of this species 

 taken in Alabama showed the food to consist of Hymenoptera, beetles, 

 weevils, and caterpillars." Professor Aughey (1878) observed this 

 warbler catching locusts in Nebraska. 



Behavior. — S. Harmsted Chubb (1919) describes the behavior of 

 the cerulean warbler as follows : 



A bird more difl5cult to observe I have rarely if ever met with. His life seemed 

 to be confined almost entirely to the tops of the tallest deciduous trees, where he 

 would generally feed, with apparent design, on the side most remote from the 

 would-be observer, exhibiting a wariness not expected on the part of a warbler, 

 and finally leaving the tree, the first intimation of his departure being a more 

 distant song. He never remained in the same tree top more than eight or ten 

 minutes at a time and yet rarely ventured out of hearing distance from the center 

 of his range. Fortunately, he would sometimes take a perch on a bare twig and 

 sing for several minutes, but the perch was always high and generally with the 

 sky as a poor background for observation. Had it not been for the almost in- 

 cessant singing, being heard almost constantly from daybreak until nearly dark, 

 the task of identification would have seemed hopeless. 



Voice. — Aretas A. Saunders writes to me: "I have but six records 

 of the song of this bird. There is probably more variation in the song 

 than these records show, for all six are much alike. The song consists 

 of four to eight notes, of even time and all mainly on one pitch, fol- 

 lowed by a trill about a tone higher, the latter, in all of my records, 

 pitched on Q"". The first notes, in one of my records, are upward 

 slurs, and in two others the first note of the group slurs upward, but 

 in all of the others all of the notes are of even pitch and not slurred. 

 The pitch varies from G'" to C". The songs are undoubtedly be- 

 tween one and two seconds in length, but I had no stop watch at the 

 time, so did not time them. The song iy rather loud and not par- 

 ticularly musical. In form the song is much like that of the Black- 

 burnian warbler, but the loudness, different quality, and lower pitch 

 distinguish it." 



Francis H. Allen (MS.) writes the song as "toee luee wee wee hzzz., 

 heard many times without any apparent variation." This was some- 

 what different from the song of a cerulean I heard, which had a 

 "chippy" beginning that suggested the song of a yellow palm warbler, 



