422 BULLETESr 179, UNITED STATES NATIONAL MUSEUM 



results of his records that "bank swallows commonly breed when 

 less than one year old, that is, the first season after hatching. * * * 

 The first year bank swallows do not often return to breed in the 

 gravel pit in which they were reared; a somewhat larger number 

 return to the general region to nest. A" very much larger propor- 

 tion of adults, however, return to a gravel pit in which they have 

 nested previously while a still larger proportion return to the gen- 

 eral region where they previously have nested." The bank swallows 

 usually, if not always, have a different mate each year. Certain 

 individuals change mates before a first brood is reared; others have 

 had different mates for the first and second matings of a season. 



Bird banding has contributed definite knowledge concerning the 

 life span of birds, information concerning birds living a normal 

 life that cannot be derived by any other known method. Dayton 

 Stoner (1938) has banded 5,904 bank swallows, of which 2,834 were 

 adults and 3,070 were young. It is obvious that the age of adults is 

 not certain, but they are at least one year old, possibly older when 

 banded. Of 169 of Stoner's returns 36 (21.3 percent) were banded 

 as young and 133 (78.6 percent) were banded as adults. Eighteen 

 of the returns were one year old, 104 at least two years old, 33 at 

 least 3 years, 10 at least 4 years, and 3 at least 5 years old. One in- 

 dividual bandod as a nestling was 6 years old. 



Dr. Stoner concludes that the average life span of the bank swal- 

 low is two or three years and for the territory under consideration 

 the bank swallow does not ordinarily exceed three years. A num- 

 ber of the bank swallows attain the age of four years, and a few 

 continue life for five years, but it is very unusual for a bank swallow 

 to attain the age of six j^ears or more. 



DISTRIBUTION 



Range. — Circumpolar; breeding over the entire Northern Hemi- 

 sphere and wintering in South America, Africa, and India. 



Breeding range. — In North America the breeding range of the 

 bank swallow extends north to northern Alaska (Kowak Delta, 

 Hogatza River, Fort Yukon, and Hulahula River) ; northern Yukon 

 (Johnson Creek) ; Mackenzie (Fort McPherson, Fort Goodhope, Fort 

 Anderson, and the Lower Hanbury River) ; northern Manitoba 

 (Hayes River) ; northern Quebec (forks of the Koksoak) ; northern 

 Labrador (Okak) ; and Newfoundland (St. Georges Bay). East to 

 Newfoundland (St. Georges Bay) ; thence south along the Atlantic 

 coast to southeastern Virginia (Petersburg). South to southern 

 Virginia (Petersburg, Lynchburg, and Blacksburg) ; southeastern 

 Tennessee (Athens) ; central Alabama (Washington Ferry) ; south- 

 ern Texas (Santa Maria, Laredo, Del Rio, and Langtry) ; southern 



