THE COWBIRD, 441 



Ralph collection, represents one of the smaller-sized specimens, with lighter- 

 colored markings, and was taken near Holland Patent, New York, on May 31, 

 1884, from a nest of a Phoebe containing four of its own eggs and two of those 

 of the Cowbird. The two last named were evidently both laid by the same bird. 



171. Molothrus ater obscurus (Gtmelin). 



DWARF COWBIRD. 



Sturnus obscurus Gmblin, Systema Naturae, I, ii, 1788, 804. 



M[olothrus\ ((teryav. obscurus OouES, Birds of the Northwest, 1874, 180, in text. 



(B — , 211a, E 258a, C 314, U 495a.) 



GrEOGRAPHiCAL RANGE: Mexico and adjoining portions of the United States from 

 southern Texas to southwestern Arizona and Lower California. 



The breeding range of the Dwarf Cowbird in the United States is coincident 

 with its geograpliical distribution. It can only be considered a summer resi- 

 dent in southern Arizona, although a few appear to winter there, as I shot an 

 adult male on Rillito Creek, near Tucson, on Januaiy 24, 1873. It usually 

 arrives from its winter home in southern Mexico about the middle of March, 

 and is then found associating with diiferent species of Blackbirds, especially 

 Brewer's Blackbird, frequenting the vicinity of cattle ranches, roads, and cul- 

 tivated fields. By April 15 the flocks have scattered, and small parties of from 

 five to twelve may now be seen in suitable localities, such as the shrubbery 

 along water courses, springs, etc., where other small birds are abundant. The 

 character of its food, and its general habits as well, are similar to those of the 

 common Cowbird, which it closel}' resembles, being only a trifle smaller. In 

 middle Texas the two races intergrade to some extent, and it is claimed both 

 breed there. In the lower Rio Grande Valley, Texas, the typical Dwarf Cow- 

 bird is common, and I found it equally so in the vicinity of Tucson, Ai'izona, 

 where I have taken quite a number of its eggs. 



Mr. F. Stephens writes me that it is a common summer resident as far west 

 as the Colorado River, beyond the immediate vicinity of which he has never seen 

 it. Mr. L. Belding found it common in the streets of San Jose del Carbo, Lower 

 California, associating with Brewer's Blackbirds, during April, but he rarely saw 

 it later. It is questionable if it breeds there. 



Like its eastern relative, the Dwarf Cowbird drops its eggs in the nests of 

 other birds, principally in those of species which are smaller than itself. The 

 following is a list of those in which they have thus far been found: 



Gontopus richardsoni, Western Wood Pewee. 

 Pyrocephahis rubineus mexicanus '<^erinilion 



Flycatcher. 

 Agelaius phceniceu^, Eed-winged Blackbird. 



Icterus spurius, Orchard Oriole. 

 Icterus bullocki, Bullock's Oriole. 

 Chondestes grammacus strigatus, Western 

 Lark Sparrow. 



Icterus cucullatus, Hooded Oriole. Amphispiza biUneata, Black-throated Spar- 



loterus cucullatus nelsoni, Arizona Hooded j row. 

 Oriole. ; Peuccea carpalis, Eufous-winged Sparrow. 



