MASKED BOBWHITE Colinus virginianus ridgwayi (Brewster) 



Order: GALLIFORMES Family: PHASIANIDAE 



Distinguishing characteristics : Similar to the common bobwhite of the Eastern United 

 States but smaller. Male with breast almost pure brick red, and head and throat black 

 with variable amount of white forming a line over the eye . Plumage of females similar 

 to eastern bobwhite . 



Present distribution : Extremely localized in the central portion of the State of Sonora, 

 Mexico. Definitely known from only two areas between 1,500- and 2,500-foot elevation 

 in central Sonora where good growths of grass occur under desert shrubs and cacti. 



Former distribution : More extensive than now through middle Sonora to about 50 miles 

 north of the United States--Mexico border in central southern Arizona from the Baboquivari 

 Mountains east to the upper Santa Cruz Valley . Its habitat in Arizona was tall grass- 

 mesquite plains with some smaller shrubs and cactus . 



Status : Extirpated from Arizona in early 1900's . Now being reintroduced. Extremely 

 uncommon and localized in its present range in Sonora . Habitat very vulnerable to cattle 

 grazing. 



Estimated numbers : About 1 , 000 . 



Breeding rate in the wild : Average brood size 11 in 1968 and 14 in 1969. 



Reasons for decline : Overgrazing, lack of fire, and consequent invasion of woody species 

 of plants at the expense of grass which is essential for survival . Very short nesting 

 season gives little opportunity for renesting . 



Protective measures already taken : Field studies of ecology, life history, and present 

 distribution are underway in Sonora by a biologist of the Bureau of Sport Fisheries and 

 Wildlife. Masked bobwhites are being propagated at Patuxent Wildlife Research Center. 

 Several releases of this stock have been made in selected areas of suitable habitat within 

 historical range in Arizona by cooperative efforts of Federal and State of Arizona agencies. 



Measures proposed : Determine location of remaining populations in Sonora . Attempt to 

 induce owners to exclude cattle from these areas . Continue and expand present captive 

 propagation with stock on hand supplemented with new blood from wild birds . In available 

 habitat, determined as suitable by ecological studies in Arizona, introduce stock from 

 captive reared flocks. Purchase land for management specifically for the masked bobwhite. 



Number in captivity : About 600 in 1970 . Fluctuates greatly with use of birds for release 

 to the wild. 



Breeding potential in captivity : Good . 



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