22 LIFE HISTORIES OP NORTH AMERICAN BIRDS. 



10. Callipepla squamata castanogastris Brewster. 



CHESTNUT-BELLIED SCALED PARTRIDGE. 



Callipepla squamaia castanogastris Brewster, Bulletin Nuttall Ornithological Club, 



VIII, January, 1883, 34. 

 (B — , C — , R — , C — , U 293«.) 



Geographical range: Lower Rio Grande Valley in Texas, south to San Luis 

 Potosi, eastern Mexico. 



This well-marked subspecies is easily distinguished from the Scaled Par- 

 tridge, being a much richer and darker colored bird ^than the latter. Its range 

 seems to be a very restricted one, and is confined to the Lower Rio Grande 

 Valley in Texas and eastern Mexico. It has been taken near Fort Brown, 

 Texas, by Asst. Surg. James C. Merrill, U. S. Army, where it is rare, and it 

 extends northwestward from this locality at least to Eagle Pass, Texas. 

 According to Mr. George B. Sennett, the foothills of the Rio Grande, about 

 100 miles back from the coast, mark the eastern limit of this bird. 



"Mr. C. W. Beckham reports this subspecies from Mineral City, about 

 50 miles northwest from Corpus Christi, Texas."^ 



According to Mr. J. A. Singley, it seems to be very common about Ring- 

 gold Barracks and Rio Grande City, Texas, from which points it does not 

 extend more than 50 miles into the interior. He reports them as abundant in 

 the hilly country near Rio Grande City, and at the Las Cuevas Rancho, 15 

 miles south, and as rare at and below Hidalgo, Texas. 



The general habits of the Chestnut-bellied Scaled Partridge as well as its 

 food are very similar to those of the preceding subspecies. The mating and 

 nesting season, however, commences somewhat earlier. Full sets of eggs have 

 been taken near Rio Grande City, and at Camargo on the Mexican side of the 

 river opposite, as early as March 11, and from that time up to July 10. Two 

 broods are unquestionably raised in a season. Mr. Thomas H. Jackson, of West 

 Chester, Pennsylvania, gives the average number of eggs laid by this species 

 as fifteen, based on data taken from twenty-seven sets. The largest number 

 found in one nest was twenty-three. I am indebted to him, as well as to Mr. 

 George B. Sennett, for the loan of a number of specimens for examination. 

 Their nests are always placed on the ground ; a slight hollow in the sand is 

 scratched out by the bird, usually under a clump of weeds or grass, or a 

 prickly-pear bush. They are very slightly lined with dry grasses. The shape 

 and color of their eggs are very similar to those of Callipepla squamata. 



From the material before me it would appear that more of the eggs of this 

 subspecies are plainly and distinctly spotted than is the case with the former, and 

 they also average a trifle smaller. The average measurement of seventy-seven 

 specimens examined is 31 by 24 millimetres. The largest egg- of the series in 



'Proceedings U. S. National Museum, Vol. x, 1887, p. 656. 



