EASTERN EVENING GROSBEAK 217 



nestling on my side of the nest raised its uropygium, which was covered 

 with white down, as if to help the father remove the fecal sac. 



Both parents defend the nest and young. On July 4, 1 94 6 at the Algon- 

 quin Park nesting, I watched the pair drive off a gray jay by dashing 

 at it, giving rough buzzmg notes. They treated a bronzed grackle 

 and a robin in the same manner, and threatened a young hermit thrush. 

 They tolerated the following species near or even in the balsam fir that 

 held the nest: Golden -crowned and ruby-crowned kinglets, a myrtle 

 warbler, Blackburnian and Canada warblers, and a purple finch. 

 They chased no other evening grosbeaks and seemed tolerant of the 

 few that appeared in the nesting vicinity. 



The young birds grow quickly. An aviary nestling measured 50 

 millimeters when 51 hours old and 57 millimeters when 78 hours old. 

 The eyes begin to open on the fourth or fifth day and are fully open on 

 the fifth or sixth day. The sex of a healthy nestling can be determined 

 by the ninth or tenth day. Thus H. R. Ivor wrote in his journal of a 

 9-day old bird: "The nestling definitely seems to be a male. The 

 tail feathers have barely broken and show all black. The white of the 

 middle secondaries are very pure white." 



C. E. Hope found a fledgling male about 12 days old from a nest in 

 Algonquin Park, Ontario, on July 6, 1946 to weigh 32 grams. A 

 second young male collected on August 9 weighed 61.5 grams. The 

 Shaubs have reported on weights of juveniles trapped at their feeding 

 station at Saranac Lake, N.Y. in the summer of 1952 (Shaub and 

 Shaub, 1953). "Two females weighed 52.6 and 49.6 grams respec- 

 tively. A Juvenal male weighed 55.2 grams and an adult male weighed 

 51.2 grams." 



The young normally leave the nest on the 13th or 14th day. One 

 fledgling male, that had left the nest prematurely in Algonquin Park, 

 Ontario, was fed exclusively by its father until independent. A young 

 aviary male at 36 days from hatching was being fed from time to time 

 by its mother, although able to feed itself as well. 



Juvenal males have golden heads, and when they raise the crest to 

 to beg for food, as I have seen them do in Muskoka, they are very 

 handsome. My husband watched a juvenal female with a peach- 

 colored breast following and begging from an adult in Muskoka on 

 August 5, 1951. The young bird looked as big or bigger than the adult 

 and had a full-grown tail. Elizabeth Holt Downs (MS.) recorded the 

 dates of the arrival of the first young at her feeding station in Vermont 

 for the years 1953-1957. In 1953, 1954, and 1955 the first young ap- 

 peared on June 26. In 1956 the arrival date was July 6; in 1957, June 

 17. Juveniles out of the nest have been reported as early as the first 

 week in July in Ontario. The latest date of juvenile feeding is a young 



