216 CONSERVATION OF CANADIAN WILD LIFE 



practically uninfluenced by the agricultural development of 

 the country, their returns may be taken, not only as an in- 

 dex of the total quantity of furs of the different species of 

 fur-bearing animals taken in Canada in any year, but also 

 as a fair index of the relative abundance of these species. 

 From these figures the accompanying charts have been pre- 

 pared, and they illustrate very graphically the abundance 

 from year to year of the chief species of fur-bearers and their 

 periodic increase and decrease.* 



Varying Hare or Rabbit. — If we study the data respecting 

 the increase and decrease in abundance of the common rab- 

 bit or varying hare {Lepus americanus) , which is widely dis- 

 tributed throughout the country, especially in the north, 

 we find ample confirmation of the well-known facts respect- 

 ing the abundance from year to year of this common food 

 and fur-bearing animal. Their capacity for increase in 

 numbers is very great. 



The females usually begin to breed when a year old. 

 They bear two or three, and sometimes four to six young 

 at a time, and are said to breed two or three times in a 

 season, the period of gestation being about thirty days. 

 MacFarlane states: "The litter usually consists of three or 

 four; but when in the 'periodic' increase, females are known 

 to have as many as six, eight, or even ten at a time, and 

 then gradually return to three or four." 



If we take the periods of maximum abundance of the rab- 

 bit, according to the Hudson's Bay Company's returns, we 

 find they occurred in the following years: 



1845, 1854, 1857, 1865, 1877, 1888, 1897, and 1905, or in 

 other words in cycles of 9, 3, 8, 12, 11, 9, and 8, 

 giving an average periodic cycle of 8.5 years. 



*MacFaxlane, in his "Mammals of the Northwest Territories" (1905), a 

 memoir to which I make frequent reference, and E. T. Seton, in his book 

 "The Arctic Prairies," have called attention to these fur returns and the 

 indications they afford of the fluctuations in nximber of the fur-bearing animals. 



