480 LIFE HISTORIES OF NOBTH AMEEIGAN BIRDS. 



about two weeks old, and may then be seen sitting on some of the branches 

 close by and clamoring- for food. They are fed entirely on insects, etc., and are 

 faithfully cared for l)y the parents until able to provide for themselves. The 

 migration from the northern sections of tlieir breeding range to their winter 

 homes in Central America begins usually in August, but occasionally some birds 

 linger until September. This species is rarely imposed on by the Cowbird. The 

 eggs of the Baltimore Oriole are usually elongate ovate in shape, more rarely 

 ovate. Tlie shell is tine grained, moderately strong, and shows but little gloss. 



The ground color is ordinarily pale grayish white, one of those sul)tle tints 

 which is difficult to describe ; in a few cases it is pale bhiish white, and less often 

 the ground color is clouded over in places with a faint, pale ferruginous suffusion. 

 The egg is streaked, blotched, and covered with irregularly shaped lines and 

 tracings, generally heaviest about the larger end of the egg, with different shades 

 of black and brown, and more sparingly Avith lighter tints of smoke, lavender, 

 and pearl gray. In a few instances the markings form an irregular wreath, and 

 occasionally a set is found entirely i;nmarked. 



The average measurement of fifty-six eggs in the United States National 

 Museum collection is 23.03 by 15.45 millimetres, or about O.'Jl by O.Gl inch- 

 The largest egg of the series measiu-es 25.'J1 by 16.76 millimetres, or 1.02 by 

 0.66 inches; the smallest, 20.83 by 14.99 millimetres, or 0.82 by 0.59 inch. 



Of the type specimens, ¥o. 22644 (PI. 7, Fig. 6), from a set of four, taken 

 by the late Capt. B. F. Goss, near Pewaukee, Wisconsin, on June 7, 1872, shows 

 a rather unusual type of markings; No. 25557 (1*1. 7, Fig. 7), from a set of five, 

 Ralph collection, taken on Shelter Island, New York, June 10, 1882, represents 

 one of the finer and more profusely marked examples; No. 25558 (PI. 7, Fig. 8), 

 also from a set of five, taken by Di\ William Ij. Ralph, near Holland Patent, 

 New York, June 3, 1887, shows the coarser style of markings and a rather dai-k 

 ground color; and No. 25846 (PL 7, Fig. 9), from a set of four, taken on June 

 7, 1887, by the same collector and at the same place as the last, shows a speci- 

 men in which the markings are mainly confined to the center of the egg. 



igo. Icterus bullocki (Swainson). 



BULLOCK'S ORIOLE. 



Xanthormis bullocki Swainson, Philosophical Magazine, I, 1827, 436. 

 Icterus bullocki Bonaparte, Geographical and Comparative List, 1838, 29. 



(B 41G, 217, R 272, C 327, U 508.) 



GEOfiRAPninAL kange: Western North America; north to sonthern British Colum- 

 bia, southern Alberta, and Assiniboia, Dominion of Canada; east to western North and 

 South Dakota, western Nebraska, eastern Colorado, and western Texas; Lower California; 

 south in winter into the valley of Mexico and to Puebla. Accidental in Maine. 



Bullock's Oriote, a species as handsome and conspicuous as the preceding- 

 one, re]ilaces it in the western portions of the United States, and is likewise 

 widely distributed. Its breeding range within our borders corresponds to its dis- 



