214 CONSERVATION OF CANADIAN WILD LIFE 



feed upon the combs and nests of the bees. The number of 

 field-mice near villages and small towns is largely dependent 

 upon the number of cats, with the* result that bumble-bees 

 are said to be more abundant near such places, with a con- 

 sequent increase in the clover crop. 



When we study these phenomena as they occur in our 

 wild life, the dependence of the larger animals upon the 

 abundance of the smaller is very marked, and we discover 

 the significance of the well-known periodical increase and 

 decrease in the prevalence of many of the well-known mem- 

 bers of our wild life. 



At the bottom of the scale are the numerous species of 

 mice and voles, which constitute the food of so many of 

 the large and small predatory animals. The observations 

 of Cabot* on the rise and fall in the abundance of mice, and 

 the effect on the larger animals, are of great interest in this 

 connection, as they were made in the same region, namely, 

 northern Labrador and the interior of Ungava peninsula, 

 and during consecutive years. When he first visited the 

 region in 1903 mice were not noticeably abundant. Cari- 

 bou had been abundant through the winter, and in early 

 July passed north in large numbers, close to the coast. 

 There were some of the large predatory birds, such as falcons. 

 Few ptarmigan were seen. Foxes, the most important fur- 

 bearers of the region, were fairly abundant. By 1904 there 

 had been a noticeable increase in the numbers of mice. 

 Hawks were more numerous. Ptarmigan were fairly nu- 

 merous. Many tracks of wolves were seen, chiefly along 

 the river banks, where mice occur. A wolverene that was 

 killed was full of mice. Hawks and owls occurred inland. 

 In 1905 the mice reached their maximum abundance. 

 Cabot states: ''Sometimes two at a time could be seen in 

 the dayhght. Low twigs and all small growth were riddled 

 by them. There was a tattered aspect about the moss and 



* William B. Cabot, "In Northern Labrador," Boston, 1912. 



