334 LAND BIRDS 
616. BANK SWALLOW. — Riparia riparia. 
Famity : The Swallows. 
Length: 4.75-5.50. 
Adults: Upper parts grayish brown or sooty, darker on head and wings, 
paler on rump and upper tail-coverts ; under parts white, with abroad 
band of sooty across chest and sides ; usually a sooty spot on breast. 
Young: Similar to adults, but feathers of wings and rump with buffy or 
whitish edgings. 
Geographical Distribution : Northern hemisphere in general; in America 
migrating south in winter to Cuba and Jamaica, Central and North- 
ern South America. 
California Breeding Range: In suitable localities throughout the State. 
Breeding Season: June and July, 
Nest: In horizontal holes or burrows excavated in sand banks and banks 
of streams ; thinly lined with fine twigs, grasses, and feathers. 
Eggs: 3 to 6; white. Size 0.72 X 0.50. 
AmonG the birds that I have watched, few have been 
more timid and more difficult to study than the dull- 
colored Bank Swallows. Unless you have seen them, 
as with wings fluttering they strike the first blow into 
the hard sand or clay of the nesting site, you will be 
puzzled as to how it is done. Feet and bill divide the 
toil, and but for the wings you might suppose a small 
gray mouse at work. The soil must be stiffer than light 
sand in order to prevent a “cave in,” and not infre- 
quently clay or mixed gravel and sand are chosen. 
These offer a discouraging resistance to the delicate 
beak and claws, but the persistent little miners keep 
bravely at work in spite of obstacles, so long as human 
intruders are out of sight. An attempt to investigate 
their work or study them at close range, if persisted in, 
usually results in abandonment of the site. 
