264 



NATURE'S CALENDAR 



December 18 



like the chipmunk, no longer find any 

 warm days in which to walk abroad. The 

 latest to retire, probably, is the black bear. 

 " The time of his hibernation," to quote 

 Mathews, " is almost entirely dependent 

 upon the condition of the food-supply. 

 If food is scarce and the cold is severe, he 

 retires about the first of December ; but if 

 beech-nuts are plenty and the weather is 

 mild, he will prowl about all winter, and 

 the female will den only before the period 

 of bringing forth the young." 



Dr. Merriam, who has had much ex- 

 perience with bears in northern New 

 York, makes the same statement, and 

 asserts that the cause of retirement is 

 not " to escape either the low tempera- 

 ture or the deep snows, but to thus bridge 

 over a period when, if active, he would 

 be unable to procure sufficient food." 



The den Dr. Merriam describes as usu- 

 ally a partial excavation under the up- 

 turned roots of a fallen tree, or under a 

 pile of logs, with perhaps a few bushes 

 and leaves scraped together by way of a 

 bed, while to the first snow-storm is left 

 the task of completing the roof and fill- 

 ing the remaining chinks. Not infre- 

 quently the den is a great hole or cave 

 dug into the side of a knoll, and gener- 

 ally under some standing tree, whose 

 roots serve as side-posts to the entrance. 

 The amount of labor bestowed upon it 

 depends upon the length of time the bear 

 expects to hibernate. If the prospects 



December 19 



