BANK SWALLOW 415 



Dayton Stoner (1936b) writes of the notes of the bank swallow 

 as follows : "Nest -building as well as burrow-digging is accompanied 

 by much harsh, unmusical twittering. Thereafter comparative quiet 

 reigns during the period of egg-laying and incubation ; vocalization 

 is resumed as soon as the young are hatched. 



"When alarmed, the bank swallow gives a shrill ^ke-a-g-K' or 

 He-a-r-rll which, though much feebler, reminds one of the note of the 

 common tern. Apparently this is a warning note. Wlien uttered 

 by a swallow m flight as, for example, a frightened individual leav- 

 ing the nest, or the bander's hand, it acts as a signal to other members 

 of the colony." 



In regard to the voice of the young, Stoner makes the following 

 observations : 



Almost immediately after hatching, young bank swallows may be heard to 

 utter a fine, high-pitched "cheep" ; but the nestlings are, as a rule, inclined to be 

 silent, although hunger calls are uttered when the adults have not visited them 

 for some time. "When a family of four or five nestlings utter this call together, 

 the sound reminds one of the buzzing of a swarm of bees. Occasionally, when 

 well-fledged young are forcibly removed from the burrow, they utter a few loud, 

 shrill cries of distress, — a signal for the adults in the immediate vicinity to 

 congregate and add their own excited notes to the clamor. But unlike many 

 other passerine birds, the distress calls of the young usually are not long con- 

 tinued, even when the bird is roughly handled. Only a sharp pain then seems 

 to provoke an outcry. Ordinarily, the young individuals that occasionally 

 drop into the water likewise remain silent. 



For a few days immediately preceding abandonment of the nest, the young 

 often appear at the mouth of the burrow, twittering and warbling much after 

 the manner of the adults. At this age their voice is lower and harsher than 

 that of the adult, but within a few days no pronounced difference in timbre 

 was noted. 



Enemies. — The most important enemies of the bank swallow are 

 those predatory animals that are able to gain access to the nesting 

 burrows. In the Oneida Lake region of New York State, Stoner 

 (1936b) found the skunk {Mephitis nigra) to be one of the chief 

 offenders. He cites a case where on June 23, 1931, a skunk had dug 

 through the thick turf and into the soil to a depth of a foot to reach 

 the young in a bank swallow's nest. He notes several additional cases 

 in which the skunk was blamed for similar depredations on eggs and 

 young. Stoner states that the predatory activities of the skunk can 

 probably be attributed only to a comparatively small number of in- 

 dividuals living in the immediate vicinity of the bank swallow col- 

 onies. In general the skunk is not a serious enemy of the swallow. 



William Brewster (1903) describes in detail a very interesting 

 case where a mink destroyed a colony of bank swallows located at 

 Lancaster, Mass. On May 24, 1902, there were 108 holes, but on June 

 19 all but one pair had been destroyed by a mink. In a colony of 



