254 U.S. NATIONAL MUSEUM BULLETIN 237 paet i 



Blackbird. Three or four eggs seem to constitute the normal clutch." 



The measurements of 27 eggs average 23.3 by 16.8 millimeters; the 

 eggs showing the four extremes measure 24-8 by 17.0, 23.9 by 18.0, 

 21.3 by 16.0, and 21.9 by 15.8 millimeters. 



Incubation. — Incubation is performed by the female and she is a 

 very close sitter. The period is probably 12 to 14 days as in H, v. 

 vespertina. 



Young. — The young seem similar in every way to those of other 

 races of this species. F. M. Chapman (1897) collected a young 

 male but a few days from the nest, April 21. Because of the early 

 date he concluded that the species bred there early in March. 



H. H. Kimball found a number of juvenals with their parents in 

 the Paradise region of the Chiricahua Mountains, Ariz., from about 

 the middle of July. Young were taken from July 13 to 24, 1918, 

 and from July 10 to 23 in 1919 (collections of M. M. Peet and the 

 Chicago Nat. Hist. Mus.), 



H. S. Swarth (1904) tells us that in the Huachucas in the vicinity 

 of Miller Canyon "on July 30, 1902, 1 came upon half a dozen birds 

 scattered through the pines at an altitude of about 9000 feet. An 

 old male was observed feeding a fully jQedged young * * *." 



Food. — "When busy feeding, the birds are rather quiet," writes 

 Willard (1910). "They walk along the branches from cone to cone 

 and extract seeds which seem to form the major portion of their 

 biU-of-fare." 



W. E. D. Scott (1885) saw them "feeding on small cones in a spruce 

 tree" in the Santa Catalinas. Brandt (1951) published a report of 

 their fondness for apple seeds, and Wesley E. Lanyon (in litt.) found 

 them in hackberry trees. 



Allan R. Phillips has written me of a flock he found "at the lower 

 edge of the ponderosa pines in the Santa Catalina Mts. — a point 

 where one seldom sees them * * *. The crops (Feb. 29) were full of 

 lenticular seeds, perhaps Acer grandidentatum, which as I now recall 

 they were gathering under some walnuts." 



Behavior. — The Mexican evening grosbeaks in the Canadian Zone 

 of the Chiricahua Mountains of Arizona behave very much as do 

 their eastern relatives in the highlands of Ontario. Both live largely 

 an arboreal life, and many of their bird associates are similar. In 

 summer both fly down from the trees to the little springs for water. 

 When in the Chiricahuas in June, Peterson (1955) gives a clear picture 

 of the bird in its environment. He teUs us: 



After we had zigzagged for miles up the rugged mountain flanks to the camp 

 ground at Rustler Park we found ourselves at the edge of the Canadian Zone. 

 Here on the cool north slopes pines gave way to Douglas fir and we were not too 

 surprised when an evening grosbeak flew up from a spring where it had been 



