784 TT.S. NATIONAL MUSEUM BULLETIN 237 part 2 



easy to be sure of a moult without specimens which actually show it. 

 The freshness of many feathers in spring indicate it." 



Food. — From 17 stomachs (12 adult, 5 immature) Hyde (1939) 

 collected between April and October, he determined the food to be 

 82 percent animal matter by bulk and 18 percent vegetable matter, 

 Orthoptera comprised 36.47 percent of the August-September food, 

 Coleoptera 19.3, Heteroptera 12.2, Lepidoptera 3.3, and Hymenoptera 

 1.8 percent. Additional items of animal matter included Diptera, 

 Neuroptera, spiders, unidentified arachnids, myriapods, and gastro- 

 pods. 



The Orthoptera eaten were crickets (especially Nemobius sp.), 

 grasshoppers, and katydids; the Coleoptera were weevils (mostly), 

 chrysomelids, carabids, scarabaeids, and histerids; the Heteroptera 

 were lygaeids, pentatomids, and a few others; the Lepidoptera included 

 caterpillars of cutworms (noctuids); and the Hymenoptera were 

 andrenids (chiefly), ants, ichneumonids, tenthredinids, and chalcids. 

 All the insects were species found on or near the ground in the vegeta- 

 tion in which the bird fives. 



Seeds of grasses constituted 6.2 percent of the total food; ragweed 

 9.2 percent (75 to 85 percent in two specimens taken in October); 

 Pologonaceae 1.6; and sedges less than 0.5 percent. Hyde adds: 

 "It is nearly certain that if faU, winter, and early spring specimens 

 had been examined in proportion to those collected in the summer, the 

 percentage of vegetable matter would have been much higher." 



The principal food brought to day-old nestlings was smooth noctuid 

 caterpillars. These and soft abdomens of Orthoptera (katydids, tree 

 crickets, and grasshoppers) were the chief items fed to young birds 

 the first 3 days after hatching. After the third day the parents 

 brought a greater variety of insect food, though caterpillars and 

 Orthoptera still predominated. Other items Hyde saw fed to the 

 nestfings included sawffies (Cimbex), a large garden spider (Argiope), 

 and a firefly (lampyrid). 



Voice. — "More often heard than seen" describes Henslow's sparrow. 

 Unless the bird happens to be singing, its presence is easily over- 

 looked. Though its unobtrusive song has been described (Peterson, 

 1947) as "one of the poorest vocal efforts of any bird, * * * a hic- 

 coughing *tsi-fick'," it is characteristic and readily identifies the 

 singer. It is sometimes given from concealment in the grass, but 

 more usually from a weed stem or bush just above the level of the 

 surrounding vegetation. 



Though the song is generally heard as two short buzzy notes, often 

 described as "flee-sic," an audiospectrographic analysis of tape re- 

 cordings by Borror and Eeese (1954) revealed that it actually consists 

 of six separate notes, the last three of which are the ones usually 



