422 Birds of Colorado 



Bank-Swallow. Biparia riparia. 



A.O.U. Checklist no 616— Colorado Records— Aiken 72, p. 198 ; 

 Cooke 97, pp. 19, HI ; Rockwell 08, p. 175 ; Henderson 09, p. 238. 



Description. — Male — Above dusky brown, becoming dusky black 

 on the wings and tail, but without gloss ; below white, except for a 

 broad band of greyish-brown across the chest, extending back along 

 the flanks on either side ; a tuft of feathers on the tarsus, pale buffy ; 

 iris brown, biU black, legs dark horn. Length 4-90 ; wing 4-15 ; tail 

 2-10 ; culmen -25 ; tarsus -40. 



The sexes are alike. The young birds have the feathers of the back 

 and upper tail-coverts, also the inner secondaries and wing-coverts, 

 tipped with buffy-white and the chin tinged with buff. 



Distribution. — The Bank-Swallow, or Sand-Martin as it is called in 

 England, has a range perhaps more extensive than that of any other 

 Passerine bird. It breeds throughout Europe, northern Asia and 

 North America, in the latter continent from the Arctic regions to 

 Georgia and northern Mexico ; it goes south in winter to southern 

 Asia and Africa, and in America to the West Indies and throvigh 

 Central America to Peru and Brazil. The Bank-Swallow is quite a 

 rare bird in Colorado, or else it has generally escaped the notice of 

 observers. Aiken (72) records it as first noticed on April 26th in the 

 Fountain Valley, and there is one example in the Aiken collection 

 from Fremont eo., dated May 16th. Dennis Gale notes its arrival 

 in the Boulder Valley April 20th, but Henderson considers this record 

 doubtful ; Rockwell reports that Sullivan found it reasonably plentiful 

 near Grand Junction, arriving May 1st and departing September 1st. 

 This is the extent of the information available. 



Habits. — The Bank-Swallow breeds in large colonies, 

 making horizontal holes or burrows in sand-banks, 

 generally along streams, but often too in railway cuttings ; 

 the eggs, four to six in number, are white with a rosy 

 tinge when unblown, and measure on an average '69 x 

 •49. Sullivan dug out of a bank on the Gunnison 

 River, July 2nd, 1904, six young ones ready to fly. 



Genus STELGIDOPTERYX. 



Rather small Swallows — wing luider 4-5— with slender bills and 

 roimded, superiorly directed nostrils without an operculum ; outer 

 primary with the tips of the barbs of the outer web produced and 

 reciu-ved, so as to form a series of clinging hooks along the outer edge 

 of the wing ; this structure is only fully developed in the male, in the 



