802 U.S. NATIONAL MUSEUM BULLETIN 237 pakt 2 



observed at Barnstable, Mass., on July 19, 1957, suggest a second 

 brood. 



Young. — My data from Barnstable, Mass., indicate an incubation 

 period of 11 days. A nest under observation completed its set of 

 four eggs on July 9, 1957. On July 22 the nest contained young 

 birds 3 days old (as estimated by Woolfenden's observations and 

 measurements) which probably hatched July 19. The female alone 

 does the incubating (A. H. Norton, 1897; G. E. Woolfenden, 1956). 

 Woolfenden says: "The first indication of hatching is a crack in the 

 side of the egg along the line of gi-eatest circumference. The crack 

 is extended along this line by the egg tooth, and then contraction of 

 muscles of the neck by the embryo separates the shell into two pieces. 

 Extension of the legs frees the bird from the shell. * * * When free 

 from the shell, the young birds rest on their tarsi, abdomen and fore- 

 head; their down dries in a few minutes, and theii* skin becomes notice- 

 ably darker." He further notes that by the second day the feather 

 papillae showed through the skin, but the feathers remained sheathed 

 until the seventh day. The eyes began to open on the third day. 

 Gaping began on the day of hatching and continued to the eighth or 

 ninth day; cowering appeared on the seventh. The last egg tooth 

 was shed on the sixth day. The average weight of five nestlings, 1.7 

 grams at hatching, doubled at 2 days, tripled at 3 days, and reached 

 14.2 grams on the 10th day when most left the nest. The young 

 were fed in the nest by the female alone, and for about 20 days after 

 leaving the nest. 



William Brewster's (MS.) observations at Revere, Mass., also 

 showed the young to be fully feathered and ready to leave the nest in 

 10 days. He watched these young being fed about once each minute. 

 The adult "uttered the cup cup note almost incessantly on its way to 

 the nest but never while leaving it. On the outward trips it usually 

 carried an excrement sac of the young in its bill, dropping it 50 yards 

 or so from the nest. On the inward trips it brought a little lump of 

 food the character of which we could not ascertain. * * ♦ it alighted 

 directly at the nest and flew directly from it." He noted that the 

 interior of the mouths of the young was "yellow as gold." However, 

 nestlings I have seen have had pinkish mouth linings with a yellow 

 rim around the bill. Young have been reported well feathered and 

 nearly ready to fly as early as June 19 in Massachusetts, and by July 

 10 1 have found the marshes full of newly fledged young, though some 

 broods do not even hatch until much later than this. 



Plumages. — The adult plumage was succinctly described by F. M. 

 Chapman (1S96 ed.) : "General color of the upper parts a brownish 

 olive-green; crown olive-brown, with a blue-gray line through its 

 center; gray ear coverts, inclosed by ochraceous-buff lines, one of 



