FIELD BOOK OF MAMMALS 



sleeps during the day and moves about only at night. Except 

 when disturbed, or under exceptional circumstances, this 

 Squirrel is strictly nocturnal and for this reason is seldom 

 seen by the average observer. It has large eyes and probably 

 finds the bright light of day distasteful. Its favorite retreat 

 during the day is a hollow tree, and if such an occupied tree is 

 located the Squirrels may sometimes be driven out by rapping 

 against the trunk. Much remains to be learned of the life- 

 history of this beautiful and attractive mammal. Generally 

 the only specimens a naturalist sees are those he takes in traps 

 set overnight, although the Squirrels may be fairly common in 

 the region. 



Flying Squirrels are doubtless the most strictly arboreal of 

 our Squirrels. The peculiar specialization for gliding is 

 evidence of an almost exclusive arboreal existence and these 

 animals are not encountered away from forests. The mode of 

 aerial progression can not be truly called flight, but is rather 

 gliding. The Squirrel throws itself out and down, and with 

 spread lateral membranes converts its falling into a long 

 gliding swoop which may turn up a short distance at the close 

 of the "flight." Except for some slight variation of the angle 

 of fall, the Squirrel has little control of its course once it is in 

 the air. The broad, flat tail probably functions as a depress- 

 ing or elevating mechanism to steepen or flatten the fall, to a 

 certain degree. 



Flying Squirrels have a more or less omnivorous appetite 

 and, besides the nuts and vegetable food enjoyed by Squirrels 

 in general, are frequently attracted by the meat-baits of the fur 

 trappers, often proving a great nuisance in this respect. 



These animals make their nest in natural cavities in tree 

 trunks and in old Woodpecker holes. The Squirrels are 

 active throughout the winter and do not hibernate; cold 

 apparently has no terror for the Flying Squirrel, for one sub- 

 species ranges across the Arctic Circle. 



The number of young in a Flying Squirrel litter is three 

 to six, and I have seen no records of more than one family 

 of young a year. 



Flying Squirrels make beautiful pets, with their soft fur 

 and attractive appearance, and are gentle in behavior, but 

 even as caged animals are not easy of observation because 

 they become active only in the dark. 



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