ANIMALS AND ARID CONDITIONS 379 
(MAX. 12 DAYS) 
(MAX. 4 DAYS) 
7 DONKEYS 
630 KG 
(MAX. 3 DAYS?) 
is har 
47 TPH Se 
WOO 
\ aay aL 
‘ i 
/ 
\ 
~~ FE 
~N os 
mae (0) SHEER 19 CAMELS 
250 KG 8500 KG 
Figure 2. Relative grazing areas for camel, donkey, and sheep. 
The radii of the circles are in the same proportions as the number of 
days (approximate) that the animals can go without water. 
The relative numbers of animals that could be maintained on these 
areas with a given constant vegetation density throughout the area, 
have been calculated. For this calculation only maintenance require- 
ments have been considered (and not growth or meat production), since 
during the summer time satisfactory maintenance of a relatively large 
stock is more important in order to have a large size herd for production 
when vegetation is more easily available in the winter. (In this con- 
sideration the question of overgrazing has been disregarded.) It is in 
the summer that the grazing area is restricted by the access to water, 
and this coincides in time with the lowest availability of vegetation in 
the same area. In winter the grazing area of the camel is not limited by 
water supply, and its range will then be determined by the practical 
limitations of the human herders. 
rapid in a small animal (sheep compared to camel), but the main- 
tenance expense per kilogram is also higher. It has been shown 
that the production per unit feed is approximately independent 
of body size of the animal; in other words, for a given amount of 
