88 U.S. NATIONAL MUSEUM BULLETIN 237 part i 



female fed a second fledgling in a near-by shrub. Another was discovered low in 

 an apple tree. We watched it sit perfectly still for more than twenty minutes, and 

 we wondered how the parents would find it. Without a sound from parent or 

 fledgling, the female flew straight to the latter, fed it, and flew away. The fledg- 

 ling remained in its place. * * * 



On July 24, we saw the parents together carrying food to three or four young in an 

 alder tree near the road. The next day the family was still in the alders. The male, 

 with a green caterpillar in his beak, flew from the orchard and fed a young bird. 

 We saw the male again on August 1 and nearly every day after that until August 8. 



Hazel L. Bradley's study (1948) indicates that newly hatched birds 

 are pinkish orange in color, almost bare, but with bits of gray natal 

 down on some of the feather tracts. There are large bulges for the 

 eyes, which are closed and membrane-covered at first. One bird 

 opened its eyes at the age of four days; all had the eyes opened at five 

 days. The large wing feathers seemed to be emerging from their 

 sheaths at five days of age, and pin feathers also appeared along other 

 feather tracts, particularly on the back. At six days feathers were 

 out of the sheaths and enlarging. At 11 days of age one group of 

 young was capable of flights of 20 feet or more. The female had re- 

 moved egg shells, brooded the young, fed them, and eaten or carried 

 away fecal sacs. Nest defense was the one activity in which the male 

 participated. 



Commenting on helpers among birds, Alexander F. Skutch (1961) 

 notes for indigo buntings that "juveniles fed still younger birds in 

 captivity." And Val Nolan, Jr. (1961) found that "Prairie Warblers 

 accept and feed nestling Indigo Buntings" and that the buntings will 

 accept young prairie warblers. 



Few data are available for productivity. In Michigan, Berger 

 (1951) notes: "From eight eggs in four non-parasitized nests, six 

 buntings were fledged. Five parasitized nests containing seven host 

 and ten Cowbird eggs fledged two buntings and four Cowbirds." 

 Phillips (1951) found that 18 young fledged out of 41 eggs laid. 



Cowbird parasitism. — As suggested above, a serious factor in the 

 breeding success of indigo buntings is nest parasitism by the brown- 

 headed cowbird {Molothrus ater). Berger's study (1951) in Michigan 

 revealed the fact that five out of nine bunting nests were parasitized; 

 three contained one cowbird egg, one contained two, and one contained 

 four eggs. In these nests four of the cowbird eggs hatched and all 

 four young cowbirds were successfully reared. In Ohio, Phillips (1951) 

 found that 6 out of 14 nests were parasitized and one cowbird fledged 

 from seven eggs laid. Howard Young (1963) gave the following 

 summary for cowbird parasitism on the indigo bunting: 12 out of 26 

 nests were parasitized; 6 out of 17 cowbird eggs hatched and all 6 

 fledged. The first recorded breeding of the indigo bunting in Califor- 

 nia was in Los Angeles County where Don Bleitz (1958) found a nest 



