388 Mr Buxton, Animal Oecology in Deserts 



Animal Oecology in Deserts. By P. A. Buxton, M.A., Fellow of 

 Trinity College, Cambridge. 



[Read 7 March, 1921.] 



The following notes are the outcome of a somewhat extended 

 sojourn in Mesopotamia and N.W. Persia during the war. Con- 

 ditions were very unfavourable for consistent investigations. I take 

 this opportunity of publishing my unfinished observations, in the 

 hope that they will furnish raw material for others. Aspects of the 

 subject which are already well known have been entirely omitted 

 from this short paper in which comprehensiveness is not aimed at. 



Climatic conditions. 



It is of course well known that deserts are dry, and many of 

 them hot as well. It must be clearly recognized that well-nigh all 

 the hottest places in the world are in desert or semi-desert country, 

 and that cold is almost as characteristic of deserts as is heat. Wind 

 too must be considered as a factor with which the desert fauna 

 has to contend. At Menjil in N.W. Persia the wind sweeps through 

 a pass in the Elburz mountains with such velocity that one can 

 barely stand against it. This wind blows with great regularity from 

 about 9 a.m. till sundown throughout the warm weather. It is 

 caused by the daily heating of the N. Persian plateau under the 

 sun's rays; the heated air rises and is replaced by an inrush from 

 the sides: at Menjil, this inrush is concentrated in a rocky defile. 

 Such a terrific but steady wind must be an important spreader of 

 small organisms. A large camp at Ruz in the valley of the Diyala 

 in E. Mesopotamia was smitten by an exaggerated dust-devil early 

 in November, 1918. The wind carved a lane through the camp 

 ripping every tent that lay in its path: heavy articles of kit were 

 blown through the air and deposited on the opposite bank of the - 

 Ruz canal: an officer of my acquaintance was pulled out of his 

 tent w^th all his camp furniture and dropped twice, with such 

 violence that three of his ribs were broken. Such winds are rare, 

 but in most desert countries small dust-devils are common; they 

 wander about the desert in a somewhat aimless manner, sweep 

 debris, bushes, etc. from the ground, and drop them later in a 

 different place. The fact that so many desert animals hve beneath 

 rocks and excavate burrows is possibly to be explained as an 

 attempt to reach an equable temperature, and to avoid wind and 

 dust: the generally accepted explanation is, I believe, that the 



