598 REPORT OF NATIONAL MUSEUM, 1893. 



Texas, the typical Dwarf Cowbird is common, and I found it equally so 

 in tlie vicinity of Tucson, Ariz., 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 tbe Colorado River, beyond the immediate vicinity of which 

 he lias 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 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: 



Coniopus rkhardsoiii, Western Wood i Canlinalis cardinalis canicaiidus, Gray- 



Pewee. 



Pyrocejihalus rubineiis mcxicanus, Vermil- 

 lion Flycatcher. 



Ageluius phccnicem, Red-winged Black- 

 bird. 



Icterus cncuUatus, Hooded Oriole. 



tailed Cardinal. 



SporophUamorelleti sharpii, Sliarpe's Seed- 

 eater. 



Piram/a rubra cooperi, Cooper's Tanager. 



Vireo noreboraceiisis, White-eyed Vireo. 



Vireo beUil, Bell's Vireo. 



Icterus cucullatus nelsoni, Arizona Hooded Vireo bellii 2>usiIIus, Least Vireo. 



Oricde. HeJminthopliila lucice, Lucy's Warbler. 



Icterus spurius, Orchard Oriole. j Dendroica astiva sonorona, Sonora Yel- 



Icterus buUocki, Bullock's Oriole. j low Warbler. 



Choiidestes grauwuicus strirjatus, Western | GeotkJypis trichas occideniaUs, Western 



Lark Sparrow. 

 Amphlspiza bilineata, Black - throated 



•Sparrow. 

 Peucaacarpalis, Rufous-winged Sparrow. 

 Melospiza fasciaia fallax, Desert Song 



Sparrow. 

 Embernaf/ra rufivirgata, Texas Sparrow. 



Maryland Yellow- throat. 



Icteria rireus longicauda, Long-tailed 

 Chat. 



Mimus polyglottus, Mockingbird. 



P.olioptila plumbea, Plumbeous Gnat- 

 catcher. 



Sialia mexicatia, W^estern Bluebird. 



Doubtless a number of others still remain to be added. 



According to my observations the Least Vireo seems to be oftener 

 imposed upon, in southern Arizona at least, than any other bird; the 

 Desert Song Sparrow, Black-tliioated Sparrow, and Vermiliou Fly- 

 catcher following in the order named. 



The earliest date known by me on which an egg of this subspecies 

 was found is April 18, the latest August 2, showing that the laying 

 season lasts considerably longer than with Molothrus ater, and it 

 appears to be at its height during the month of June. 



I found it almost impossible to obtain a full set of the Least Vireo's 

 eggs; nearly every nest found contained I or 2 eggs of this parasite, and 

 usually only 1 or 2 of its own, and the latter were frequently punctured. 

 In fact, this was so often the case that I am inclined to believe that it is 

 done purposely and not by accident; but whether made by the beak 

 or claws of the bird I will not venture to say, but believe it is done 

 with the latter. In many nests I found 1 or 2 of the owner's eggs thrown 



