Soils 
Sandy, loamy, clay, or gravelly to stony soils are the rule in 
imperial habitat. Rough, rocky surfaces are avoided. Saline or 
alkaline flats, largely bare in character but with scattered patches 
of vegetation were attractive to many birds. In Siberia, Dement'ev 
(15) mentions gravelly to sandy soils in the foothills and clay, 
overgrown with open salt marsh vegetation east of the Caspian Sea as 
being suitable for sandgrouse, 
Climate 
Sandgrouse of the genus Pterocles, for the most part, prefer 
warm to hot, arid habitats. The imperial is, to some extent, an 
exception in that it also thrives under somewhat cooler and less arid 
conditions than do other members of this group. Many sandgrouse roam 
widely, but the imperial, while resident in some areas, has adapted 
itself to a wider range and a greater variety of climatic conditions, 
than most, because of its semimigratory habit. 
Of the summer range 
The breeding and summer range for the imperial sandgrouse lies 
roughly between the July isotherms of 70° and 80°F. in Spain and north 
Africa and between 75° and 85°F. in Asia. In this range the average 
maximum temperatures for July are normally from 859 to 1OO°F, with 
several stations recording from 110° to 114°F. Average minimum temper- 
atures in July run for the most part from 56° to 73°F., with a low of 
43°F, in Siberia and a high of 76°F. in Afghanistan. 
In central Turkey, nesting commences at average maximum tempera- 
tures of 50° to 64°F. and average minimum temperatures of 35° to 40°F. 
Similar temperatures on the breeding grounds in North Africa are 
slightly higher. In both areas nests have been reported as early as 
mid-April and in central Turkey I located a nest with eggs in late 
August near Konya where average maximum temperatures were 86°F., and 
average minimum temperatures were 58°F, Nesting in southern Siberia 
begins in early to mid~May in the lowlands about the Syr-Darya River 
(15). Average maximum and minimum temperatures for May in this region 
are 92° and 40°F. Further east nesting commences 3 weeks to a month 
later, when temperatures approximate those of the Syr-Darya region for 
May. Average monthly temperatures for stations within the breeding 
range of the imperial sandgrouse are presented in table 6. 
The pattern of precipitation throughout the breeding and summer 
range is one of very moderate to fairly high rainfall in March and 
April and, in some parts, well into May. June through September is 
generally very dry with a modest to substantial increase in precipi- 
tation throughout the fall, Annual precipitation within the summer 
range is usually 10 to 15 inches, but several stations record less 
than 5 inches and a few above 20 inches. 
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