THE BURROWING OWL. 27 



farther disturbed, their flight is continued until they 

 are no longer in view, or they descend into their 

 dwellings, whence they are difficult to dislodge. The 

 burrows into which these owls have been seen to 

 descend, on the plains of the river Plortte, where 

 they are most numerous, were evidently excavated 

 by the marmot, whence it has been inferred by Say 

 that they were either common, though unfriendly 

 residents of the same habitation, or that our owl 

 was the sole occupant of a burrow acquired by right 

 of conquest. The evidence of this was clearly pre- 

 sented by the ruinous condition of the burrows ten- 

 anted by the owl, which were frequently caved in, 

 and their sides channelled by the rains, while the 

 neat and well-preserved mansion of the marmot 

 showed the active care of a skilful and industrious 

 owner. 



" We have no evidence," adds Bonaparte, " that 

 the owl and marmot habitually resort to one bur- 

 row ; yet we are well assured by Pike and others, 

 that a common danger often drives them into the 

 same excavation where lizards and rattlesnakes also 

 enter for concealment and safety. Throughout the 

 region traversed by the expedition, the marmot was 

 unquestionably the artificer of the burrow inhabited 

 by the owl."* 



CHAPTER II. 



GROUND BUILDERS. 



THE essential requisites of a bird's nest are warmth 

 and security, a certain degree of heat being indis- 

 pensable for hatching the eggs and fostering the 

 * C. L. Bonaparte, Amer. Ornith. vol i., p. 72. 



