258 LAND BIRDS 



The young oi Cliff Swallows are fed by regurgitation 

 of small insects. Theee are caught, scoop-net fashion, 

 by the adults in flying through swarms of the gnats and 

 other small winged insects that hover in the air morning 

 and evening, or that dance in the sunshine of mid-day. 

 Once every ten or fifteen minutes is the usual time for 

 a meal, but the intervals are shorter early in the morning 

 after the night's fast, and late in the afternoon. 



617. ROUGH-WINGED SW MA.OV^ . — Stelgidopteryx 



serripennis. 



Family : The Swallows. 



Length: 5.00-5.75. 



Adults : Upper parts dull grayish brown, darker on wings and tail ; ter- 



tials usually margined with grayish ; under parts plain brownish 



gray ; belly and under tail-coverts white. 

 Young: Similar to adults, but plumage more or less tinged with brown ; 



wings with broad cinnamon tips and margins. 

 Geographical Distribution : United States, from Atlantic to Pacific, and 



adjoining British Provinces ; migrates to Guatemala. 

 California Breeding Range: Below Transition zone, east and south of 



humid coast belt. 

 Breeding Season : May and June. 

 Nest : In crevices of stone walls and bridges, and in holes in banks ; 



made of grasses and straws ; lined with a few feathers. 

 Eggs: 3 to 6 ; white. Size 0.75 X 0.53. 



I 



Although sometimes confounded with the bank 

 swallow, the Rough-winged is slightly larger, lacks the 

 sooty chest-band and clear white under parts, and has 

 in addition the distinguishing serrated outer web of the 

 outer primary. Both this variety and the bank swallow 

 difler from the other members of their family in their 



