234 MAMMALIA. 



and is fond of corn and several kinds of grain. It also eats the 

 larvae of certain insects. In this region the beechnut constitutes 



o 



its staple commodity, as it does that of all our squirrels, and 

 since this nut is produced in large quantity each alternate year, 

 we are able to predict with considerable certainty the periods 

 when the Chipmunk will be abundant. For wherever, in autumn, 

 this animal finds a sufficient supply of nuts he is sure to remain 

 until the following summer. Here, in beechnut years, the fore- 

 runners of the great migration arrive in September, and by the 

 first week in October the woods literally swarm with them. Find- 

 ing an abundance of food they immediately establish themselves 

 for the winter, and begin at once to hoard up large stores. They 

 are the least hardy of our squirrels, commonly going into winter 

 quarters before the middle of November, and rarely appearing 

 again in any numbers till the warm sun, in March or April, has 

 caused plots of bare ground to appear between the snow-banks. 

 Early thaws sometimes bring them out in February ; and after 

 having once emerged, they often make little excursions over the 

 snow during pleasant days, though the temperature may be several 

 degrees below freezing. In running from tree to tree, even when 

 not pursued, the length of their bound varies from twenty-five to 

 thirty-four inches (635 to 863 mm.), a long leap for so small an 

 animal. The season of spring is occupied with the duties of rear- 

 ing the young, which, before June, are old enough to leave the nest. 

 At this time the species attains its maximum in numbers, the 

 young and old together inhabiting all parts of the woodland. Fore- 

 seeing that the nut crop will fail (this being the even year), they 

 commonly emigrate in July and do not again appear till September 

 or October of the ensuing year. 



Briefly, then (leaving out of consideration the small number 

 of resident individuals, and the migrants that sometimes pass 

 through on their way to distant parts), we find that Chipmunks 

 reach the Adirondack region during September or October of the 



