CHAPTER XV 



EBB AND FLOW OF ANIMAL LIFE 



Throughout this voyage we were struck by the rarity 

 of some sorts of animals and the continual remarks 

 that three, five, or six years ago these same sorts were 

 extremely abundant; and in some few cases the con- 

 ditions were reversed. 



For example, during a week spent at Fort Smith, 

 Preble had out a line of 50 mouse-traps every night 

 and caught only one Shrew and one Meadowmouse in 

 the week. Four years before he had trapped on exactly 

 the same ground, catching 30 or 40 Meadowmice every 

 night. 



Again, in 1904 it was possible to see 100 Muskrats 

 any fine evening. In 1907, though continually on the 

 lookout, I saw less than a score in six months. Red- 

 squirrels varied in the same way. 



Of course, the Rabbits themselves were the extreme 

 case, millions in 1904, none at all in 1907. The present, 

 then, was a year of low ebb. The first task was to 

 determine whether this related to all mammalian life. 

 Apparently not, because Deermice, Lynxes, Beaver, 

 and Caribou were abundant. Yet these are not their 

 maximum years; the accounts show them to have been 

 so much more numerous last year. 



There is only one continuous statistical record of 

 the abundance of animals, that is the returns of the 



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