460 BULLETIN 17 9, UNITED STATES NATIONAL MUSEUM 



rustic bridges ; cases have even been recorded of nests built in a bole in a tree 

 about thirty feet from the ground, and in the forking branch of a sycamore. 

 In its wild state in mountainous or rocky localities this bird naturally builds 

 against the sides of cliffs under overhanging ledges of rock, or in caves; but 

 in Great Britain it usually seeks the habitations of men for nesting-sites. 



The nest is always open above; the walls thick, and formed of mud-pellets 

 mixed with straw, hay, or hair ; the lining consists of fine grass-stems, usually 

 almost concealed by a quantity of feathers, though in some instances these 

 are absent. 



In addition to the above-mentioned nesting sites, most of which 

 may be considered as fairly normal, many unusual sites have been 

 recorded. 



One of the most remarkable is Yarrell's (1876-82) time-honored 

 account of a nest "built on the wings and body of a dead Owl, hang- 

 ing from a rafter in a barn" ; he also mentions "a bracket, a picture- 

 frame and a bell-crank. * * * the half-open drawer of a table, 

 and the loop of a chain in a boathouse." Stephen J. Wliite (1908) 

 tells of a nest built on a glass shade hanging over a gas burner in a 

 stable; and there are other records of nests on lamp shades, hanging 

 lamps and electric light bulbs. F. K. Staunton (1929) shows a 

 photograph of three nests on a hat, two on the brim and one inside, 

 hanging on the wall of a disused stable. Evidently, when normal 

 nesting sites are scarce, these swallows will use almost any suitable 

 receptacles for their nests that will offer reasonable support. 



Eggs. — Dr. Butler (1896) says of the eggs that "the ground color is 

 pure white, appearing rosy when not incubated; speckled, spotted, 

 and occasionally heavily blotched with deep pitchy brown, often 

 intermixed with sienna reddish spots, and with lavender grey shell- 

 spots; in some eggs the spots are small and tolerably evenly distrib- 

 uted over the entire surface, sometimes they are larger, and princi- 

 pally collected at the larger end; sometimes there is an imperfect 

 zone of spots, and even large blotches near the larger end; some eggs 

 are elongated ovals, others short and well formed." 



According to Witherby's Handbook (1920), the usual clutch con- 

 sists of 4 or 5 eggs, sometimes 3 or 6, and as many as 8, or even 9, 

 have been recorded. The measurements of 50 British eggs average 

 20.2 by 13.9 millimeters. 



Young. — The incubation period varies from 14 to 15 days, more or 

 less. Both sexes share the duties of incubation and the care of the 

 young, which remain in the nest 20 to 22 days, if undisturbed. Gen- 

 erally two and sometimes three broods are reared in a season. Capt. 

 Boyd's (1935) inquiry for 1934 reported that "in all, 2,665 young 

 were ringed or counted, giving an average of 4.01 for all broods 

 recorded." 



Dom Ethelbert Home (1924) gives an interesting account of how 

 young swallows are fed; he had removed the nest, with the small 



