flests in Buildings, Bridges, Walls, Etc. 



Other natural cavities, wiiile in the more thickly settled regions 

 they have utilised the nesting places provided for their conven- 

 ience by man. It will probably not be many years before hollow 

 trees will no longer be used, except possibly as roosting places. 

 The breeding season lasts from the middle of May until July, two 

 broods being reared ; after the young of the first brood are strong 

 enough they commence flocking, and may be seen early in July 

 flying in large numbers over the low lands; these are joined by 

 the second broods and the parents about the beginning of August, 

 so that the flocks contain countless numbers. In the early 

 morning, as the sun appears on the horizon, these birds sit along 

 the telegraph wires sunning themselves and making their morn- 

 ing toilet. 



616. Bank Swallow : Clivicola riparia (Linn.) 



Adult — Upper parts and band on breast grayish brown; under 



parts white. Length — 5.20. 

 Breeding Range — Throughout North America. 



The nest is composed of small twigs, grass, and feathers, 

 placed in a hole made in the face of a bank, usually near water, 

 the banks of a river being most suitable. The eggs are white, 

 the number being usually 4 or 5, sometimes as many as 7. 

 Size — .68 X .50. 



The Bank Swallows generally breed in large colonies, occu- 

 pying the entire face of a bank, which they honeycomb with their 

 nesting holes ; these excavations are usually about twenty inches 

 deep, but some are as much as four feet from the surface. 



These birds are rather smaller than the rough-winged swal- 

 low, and may be distinguished by the grayish band across the 

 breast. The breeding season begins about the middle of May, 

 two broods being reared. 



617. Rough-winged Swallow: Steigidopteryx serripennis 



(Aud.) 



.<4(/«//— Upper parts grayish brown; under parts gray, breast 

 shading into white on the belly. The outer wing feather 

 (first primary) is edged with "recurved booklets," and is 

 rough to the touch. Length — 5.75. 



Breeding Range — Throughout North America; in the Eastern 

 States from Connecticut southward. 



90 



