EASTERN EVENING GROSBEAK 215 



least 14 days. In the Ivor bird observatory at Erindale, Ontario, 

 the incubation periods for three marked eggs were 12, 13, and 14 

 days, respectively. 



One of Ivor's birds laid a second clutch; the first egg appeared 

 when the only nestling of the first set was 1 1 days old and stiU in the 

 same nest. Young birds recently fledged have been seen as late as 

 mid-August in Ontario and on August 30 in Vermont, according to 

 EHzabeth Holt Downs (MS.). B. M. Shaub (1958) reports a young 

 male still in juvenal plumage at his Northampton, Mass., feeding 

 station on Oct. 26, 1957. These records suggest the possibility of 

 two broods occasionally in the wild. 



Young. — When the young hatch, the eggshell may be removed by 

 either parent. In one case the female ate all the shell. 



At hatching, the nestling is much like the young of the rose-breasted 

 grosbeak, but the skin is darker. The little bird appears very red, 

 with damp gray feathers on its head. These neossop tiles are about a 

 quarter-inch long and dry within 25 minutes. Paul Kuntz (1939) 

 gives his impression of the young: "They were strong and healthy 

 chicks, all black with a fluffy down. They looked exactly Uke young 

 Bullfinches." My own notes read: "The white natal down sticks out 

 from the top of the head. The membrane covering the eye looks 

 purplish and very large. The bill is yellow. The egg-tooth is like 

 the tiniest white bead on the upper mandible. The gape is white. 

 The mouth and pharynx have an iridescent appearance — tones of 

 violet and carmine." My notes for the second day state: "When the 

 babies are not raising their heads, they throb with every 'peep' they 

 utter. The natal down is perfectly placed to cover them as a blanket 

 while in the nest. They lie beUies down. Bellies and throats are 

 bare, but down grows on head, wings, and tract down the back." 



Parents of newly hatched aviary nestlings at Erindale, Ontario, 

 fed them a gruel of masticated earthworms and mealworms, which 

 they first chewed for some time until a dark liquid stained their 

 bills. We watched wild adults in the Nipissing District of Ontario 

 feeding the young similarly on the masticated larvae of the spruce 

 bud worm (Choristoneura fumiferana Clem.). When the greenish bills 

 of the adults become stained dark brown from masticating insect 

 larvae, it is a sure sign they are feeding their young. The spruce bud- 

 worm in all stages of development is the main item of insectivorous 

 food for nestling evening grosbeaks wherever both the insect and 

 the bird occur together. Moreover, the birds often appear for the 

 first time or in unusual numbers wherever there is an outbreak of 

 spruce budworm during the breeding season (see under Food, p. 224). 



A number of evening grosbeak stomachs from the collection of 

 the Royal Ontario Museum of Zoology, including those of juvenals, 



