442 LIFE HISTORIES OF NOETH AMERICAN BIEDS. 



Melospiza fasciata fallax, Desert Song Spar- 

 row. 



Umbernagra rufivirgata, Texas Sparrow. 



Piranga rubra cooperi, Cooper's Tanager. 



Cardinalis cardinalis canicaudus, Gray -tailed 

 Cardinal. 



Sporophila morelleti sharpii, Sharpe's Seed- 

 eater. 



Vireo noveboracensis, White-eyed Vireo. 



Yireo bellii, Bell's Vireo. 



Vireo bellii pusillus, Least Vireo. 



Helminthophila lucice, Lucy's "Warbler. 



Dendroica cestiva sonorana, Sonora Yellow 

 Warbler. 



Dendroica ehrysoparia, Golden - cheeked 

 Warbler. 



Geothlypis trichas occidemtaZ/'s, Western Mary- 

 land Yellowthroat. 



Icteria virens longicauda, Long-tailed Chat. 



Mimus polyglottus, Mockingbird. 



Polioptila plumbea, Plumbeous Gnatcatcher. 



Sialia mexicana, Western Bluebird. 



Doubtless a number of other names 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-throated Sparrow, and Vermilion Flycatcher 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 

 apparently considerably longer than with Molothrus (iter, 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 eggs of the Least 

 Vireo, nearly every nest containing one or two eggs of this parasite, and usually 

 only one or two 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 the claws of the bird I will not 

 venture to say; believe, however, it is done by the latter. In many nests I found 

 one or two of the owners' eggs thrown out and broken, and occasionally every one, 

 the foster parent sitting on the parasite's eggs alone. Among other instances I 

 found this to be the case in a nest of the Plumbeous Gnatcatcher, which was 

 placed in a thick mistletoe bunch growing from a limb of a mesquite tree, about 

 15 feet from the ground and well hidden. I first observed the nest on June 10, 

 1872, when it contained a single egg; on visiting it again on the 17th the female 

 was sitting on a couple of Dwarf Cowbird's eggs alone, and on looking on the 

 ground I found the remnants of three eggs, which evidently had been thrown 

 out. Bullock's Oriole may occasionally rid herself of the parasitic egg; at any 

 rate I noticed the remains of one lying under a nest of this species, with portions 

 of one of her own. This nest contained only three eggs of the rightful owner, 

 and the bird was sitting on these. The largest number of Dwarf Cowbird's eggs 

 found by me in one nest was three, that of a D esert Song Sparrow, and all of its 

 own eggs were missing. I several times found nests containing single eggs of 

 this parasite abandoned, and also picked up two uninjured from the ground, 

 where they evidently had been dropped by the bird, not finding a suitable nest 

 in time to deposit them. None of the young of the foster parents seem to survive 

 the advent of a young Cowbird in their nest longer than two or three days, 

 as they are soon starved by their more vigorous and voracious foster brother. 

 After the young Dwarf Cowbird is old enough to care for itself it abandons its 



