Nests in Buildings, Bridges, Walls, Etc. 
other natural cavities, while 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.) 
Aduit—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: Stelgidopteryx serripennis 
(Aud.) 
Adult—Upper parts grayish brown; under parts gray, breast 
shading into white on the belly. The outer wing feather 
(first primary) is edged with ‘‘recurved hooklets,” and is 
rough to the touch. Length—5.75. 
Breeding Range—Throughout North America; in the Eastern 
States from Connecticut southward. 
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