10 



NORTH AMERICAN FAUNA 65 



The upland on each side of the canyon walls is barren, with gravelly 

 hills and no cover for whitewings. The only habitat between these 

 two canyons is in small, isolated coves in the river bottom and at the 

 moutlis of tributary arroyos or washes where there are scattered 

 clumps of tamarisk (Tamarix) , mesquite (Prosopis) , and associated 

 trees. 



Formerly there was much more nesting habitat in the river bottom- 

 land from Presidio to El Paso. From Presidio northward almost all 

 river bottom woodland that was suitable for nesting has been cleared 

 for agricultural crops for a distance of approximately 25 miles, except 

 for an occasional thin fringe near the river. From near Chinati 

 north to Ruidosa and locally beyond as far as Indian Hot Springs 

 there are occasional coves of woodland, chiefly of dense tamarisk and 

 mesquite, that offer nesting cover for whitewings. When this part of 

 the Rio Grande was scouted by plane in 1949 no adequate cover 

 for white-winged doves was seen north of Esperanza to El Paso. 



Although most of the specimens of grandis were collected near 

 Ruidosa where the eastern edge of the river bottomland meets the 

 foothills, the doves flew in from the direction of the Chinati Moun- 

 tains. This range is to tlie east, and its highest elevation, Chinati Peak, 

 is 7,730 feet. Local hunters said tlie whiteAvings nested in the oak 

 woodland of the mountains. How many grandis nest in the oak wood- 

 land of the Chinati Mountains and how many utilize other plant 

 associations remains to be determined. 



SPECIMENS EXAMINED 



United States: Texas (Presidio County) : Chinati, Ruidosa, and 

 near Ponenir. 



All white-winged doves in the interior highlands of Mexico have 

 been refeiTed to the race mearnsi (Friedmann et al., 1950), but breed- 

 ing specimens collected there ha\'e longer wings and tail, shorter 

 bill, and average slightly grayer plumage than Arizona mearnsi. Birds 

 from the more northern highlands, as in Nayarit and Durango, are 

 slightly darker than those of Oaxaca and Puebla, but they too have 

 longer wings and tail than mearnsi. Study of these highland birds 

 confirms that they are a distinct subs{>ecies which may be named: 



Zenaida asiatica monticola^ new subspecies 

 Mexican Highland White-winged Dove 



CHARACTERS 



It has shorter wings and tail than grandis. Birds from the highlands 

 of Nayarit, Durango, and more northern States average browner 

 than grandis, but those from Puebla and Oaxaca average slightly 



