DO SWALLOWS HIBERNATE? 161 



of carefully studying for the past three years are the bank- 

 swallow, the cliff-swallow, the barn-swallow, and lastly the 

 swallow-like swift, universally known as the chimney- 

 swallow. 



I do not propose to give here an extended account of 

 the habits of these four species of well-known birds, but 

 to relate the occurrences that I have witnessed, which 

 seemed to bear upon the question. These birds I will 

 treat of in the order named. 



Probably the most abundant of all our swallows is that 

 known as the bank-swallow, a name derived from the habit 

 of building its nest in the steep faces of earth-banks, when 

 they are of such composition or structure that these birds 

 can safely burrow into them to a depth of several feet. 

 I say " safely," for if the earth be too yielding, and the 

 sides liable to crumble, then the bank will be abandoned. 

 In every instance that has come under my notice the cho- 

 sen banks or escarpments occupied by a colony of bank- 

 swallows had a southern exposure, and directly fronting 

 it, and never so far distant as to be out of sight, there 

 was either a pond, a creek, or the river itself. Now this 

 association of water and the colonies of bank-swallows is 

 important. 



Least susceptible to changes of weather, and depend- 

 ent upon food more than temperature, the bank-swal- 

 low is the earliest of the family to appear in spring, and 

 the last to disappear late in autumn. The alleged hiber- 

 nation is a habit that concerns us only at such times of the 

 year in early spring, when they leave their muddy 

 couches after prolonged slumber, and in autumn when 

 they seek these submarine retreats. 



Like all, or nearly all, migratory birds, the bank-swal- 

 lows return in early spring to their haunts of the preced- 

 ing summer. When I have first noted their return, often 



