SEVEN NEW WHITE-WINGED DOVES 



9 



DESCRIPTION 



Type, U. S. Nat. Mus. (Fish and Wildlife Service Collection) No. 

 481592, adult male, breeding, active milk glands, near Ruidosa, 

 Presidio County, Texas, altitude about 3,000 feet, May 25, 1957, by 

 George B. Saunders, collector's number 2662. 



Crown vinaceous drab; hindneck light purple drab; back and terti- 

 aries drab; middle rectrices nearest olive brown; throat deep olive 

 buff to avellaneous; breast light drab; abdomen pale smoke gray to 

 pale olive gray; and flanks pale mouse gray. 



MEASUREMENTS 



Males (10 specimens) : wing 166.0-175.0 mm. (av. 172.0) , tail 120.5- 

 133.0 (126.6) , tarsus 26.0-28.0 (26.5) , culmen 20.0-23.0 (21.5) , length 

 (2) 317-340 (332) , extent (2) 518-538 (526) . Females (5 specimens) : 

 wing 162.0-164.9 mm. (av. 163.5), tail 112.9-121.3 (116.5), tarsus 

 25.0-26.9 (25.8) , culmen 20.7-22.3 (21.5) , length (2) 304-306 (305), 

 extent (2) 494-498 (496). 



RANGE 



Breeds in the Chinati Mountains and adjacent parts of the Rio 

 Grande bottomland from near Presidio, Presidio County, north to 

 Indian Hot Springs, Hudspeth County, Texas. It probably also occurs 

 in the Sierra Vieja, as white-winged doves were seen flying to the 

 bottomland near Porvenir from the direction of those mountains. 



A few are reported to winter in the Big Bend region of Texas, but 

 the majority journey farther south into Mexico. How far they go at 

 that season is not known, but a specimen taken in February near 

 Presa Calles, Aguascalientes, Mexico, at 7,000 feet, has the character- 

 istics of this race. 



REMARKS 



When male specimens from the lower Big Bend (Lajitas, Castolon, 

 Chisos Mountains) are compared with those from the Chinati Moun- 

 tains and adjacent valley of the Rio Grande, in the upper Big Bend, 

 it is apparent that the latter have significantly longer wings and tail. 

 This is surprising since the two ranges are separated by less than 60 

 miles. In the collecting done from Chinati north to Porvenir, 9 of 

 10 males taken in the breeding season were typical grandis and the 

 tenth was intermediate between grandis and monticola. The ecologi- 

 cal differences between their habitats are believed to be the principal 

 basis for the separation of the two populations. 



Along the Rio Grande Valley the principal physical barriers between 

 these two populations are the Colorado Canyon, 3.1 miles in length, 

 and the Grand Canyon of Santa Elena, 7 miles in length. These are 

 very narrow, deep canyons, with vertical rocky walls rising at each 

 side of the Rio Grande, and no trees or shrubs bordering the river. 



