FLUCTUATIONS OF FUR-BEARING ANIMALS 227 



He says: "I think there is sufficient proof that they do mi- 

 grate. A question annually put to the Indians returned 

 from the woods in summer or fall was, 'What signs of marten 

 have you seen ? ' and where few of these animals may have 

 been seen in the previous winter, I would be told 'They are 

 travelUng north, south, east or west,' as the case might be, 

 and so definite was the knowledge that these Indians would 

 go that winter to head off the wanderers, and they never 

 failed to come in contact with them. These movements 

 of large bodies of the marten go on in summer till the severe 

 weather sets in, beginning again in March and continuing, 

 so far as the males are concerned, till such time as the snow 

 is not fit to travel on; and then on again during the srnnmer. 

 It is accepted beyond cavil by all northerners — that is, 

 Hudson's Bay hunters — that the hare, lynx, and marten do 

 migrate, and the fluctuation in their numbers is not con- 

 sidered to be caused by epidemics, save in the case of the 

 hare. The rabbit is always numerous where lynx and mar- 

 ten are plentiful, and it is looked upon as a sine qua non by 

 hunters and traders that it is the following up the rabbit 

 and hare that causes the migrations — that the migration is, 

 in fact, quest of food." 



That the migration of the marten and of the lynx is caused 

 by the quest of food is a fact that cannot be controverted; 

 the need of food is the explanation of the migratory move- 

 ments of most animals, whether they occur among the in- 

 sects, fishes, birds, or mammals. After the disappearance 

 of rabbits in the northern woods the lynx and marten, in- 

 creased in numbers, seek food elsewhere. Likewise the 

 predatory birds such as hawks and owls migrate southward. 

 But it is important that this migratory tendency should not 

 be confused with the phenomenon of the periodic fluctua- 

 tion. Migration is one of the earliest and most popular ex- 

 planations of the disappearance of a species of animals, but 

 Hke many popular ideas it is not founded on fact. That 



