ENGLISH SPARROW 11 



upraised crease around the larger end of the egg about one-fourth of the way from 

 the end. The young bird may break the shell with the egg tooth before the crease 

 is noticeable. In either case, a slit now appears, starting at a point where the egg 

 tooth first pushed through the shell. The slit is made in a circular direction 

 around the egg and meets the point where it started. The young is able to turn 

 itself or its head in the egg making a complete circular slit possible. The head is 

 located in the larger end of the egg and as the slit nears completion the piece of 

 shell around the head is broken off and the head is freed. The larger piece of shell 

 is now kicked free and the young forces itself out. The feet are crowded into the 

 depressions on either side of the neck while in the shell, and after hatching they 

 have a tendency to remain doubled up for several hours. Often the shell does not 

 come free from the young immediately and the female will help to remove it, and 

 when doing so may often carry the young and the shell out of the nest causing 

 early death to the unfortunate young. 



In another paper (1942) he describes the development of the young 

 in great detail, with illustrations, but I quote only from his summary: 



English Sparrows are hatched without natal down. * * * 



The egg tooth disappears and the edges of the bill change from white to lemon- 

 yellow by the fourth day after hatching. * * * 



The greatest development in the plumage of young sparrows is delayed until 

 the latter part of the period in the nest. The greatest change in appearance of 

 young English Sparrows occurs between the age of six and seven days, when 

 most of the feathers emerge and many of them lose their sheaths. 



By the tenth day after hatching the color pattern is evident, showing a wing bar, 

 and in some males a black bib. 



Practically all of the sheaths have disappeared from the contour feathers and 

 all but one-fourth of the flight feathers are unsheathed by the fifteenth day. 

 These sheaths may remain one to two weeks after the young depart from the nest. 

 The greatest amount of sheath is present in the flight feathers on the eleventh 

 day. The amount of sheathing present gives an accurate criterion of the age 

 of young birds in the nest. 



Most of the young left the nest at about the fifteenth day, but English Sparrows 

 may remain in the nest for seventeen days if entirely undisturbed. 



Males and females share about equally in the feeding of the young at the nest, 

 but the females do the greater portion of the nest sanitation. Both birds may 

 brood the young, although the female does the greater part of it, and always 

 stays in the nest during the night. The young are fed by regurgitation during 

 the first part of the period after hatching. 



There was 70.5 per cent success of survival in thirty-eight nests which produced 

 127 young from 180 eggs laid. This corresponds closely to that reported for 

 other hole-nesting species. 



The older young are able to command the most advantageous positions in 

 the nest and thus receive relatively more food and often are able to leave the nest 

 several days before the other young. The young can fly rather well upon leaving 

 the nest, considerably better than do the young of most species that nest in the 

 open. 



The young are fed by the adults for a period of two weeks, and probably more, 

 after leaving the nest. The young have a strong bond for one another. 



The young, out of the nest, may be fed entirely by one adult or by both. 



A complete post-ju venal molt begins about five weeks after the young leave 

 the nest. It began in early August and ended in mid-September at Ithaca in 

 1937. 



