ORDER RODENTIA: RODENTS 193 



most of the course of the Petit-Rhone, in rather numerous colonies ; 

 (8) on the Grand Rhone, beginning at Aries, in less numerous 

 colonies. 



The 60 or 70 known stations are certainly not the only ones. A 

 rough estimate of the total population is 300 individuals. 



The reasons for depletion are numerous and diverse. Although 

 the Beaver was always hunted for its valuable fur, it was long 

 considered, up to recent years, as harmful and thus was under official 

 ban. Trapping in submerged nets has been particularly fatal. 

 The frequent floods on the Rhone have been a serious factor in 

 destruction. 



FIG. 21. European Beaver (Castor fiber). After Brehm. 



Perhaps pollution of the watercourses in certain areas is to be 

 blamed, for autopsies have revealed tubercular lesions. It does not 

 appear from the autopsies, however, that the fecundity of the species 

 has been diminished. 



When its existence was threatened a dozen years ago, the warning 

 issued by certain naturalists rapidly bore fruit. Restrictions on hunt- 

 ing, establishment of reserves, warden service, propaganda in favor 

 of the Beaver, and appreciation of this rare animal by the local 

 population, have been effective in its conservation. Its. future seems 

 brighter, and in general the colonies seem more prosperous than a 

 little while ago. It would be easy to improve the situation by the 

 creation of more reserves, by the establishment of zones of refuge 

 at the time of floods, and by the repopulation, if possible, of old 

 abandoned colonies. (E. Bourdelle, in litt., March 6, 1937.) 



Since 1909 the hunting and capture of Beavers have been pro- 

 hibited for all time. Twenty kilometers of the Rhone have been 



