SHORT-BILLED MARSH WREN 269 



of these wrens, the nests are 'legion,' and where few birds are breeding 

 the occupied nests are difficult to find." 



Eggs. — The commonest mmiber of eggs in the nest of the short- 

 billed marsh wren seems to be 7, but as few as 4 and as many as 8 have 

 been recorded. The eggs are ovate or pointed-ovate, the shells are 

 thin and very fragile, and the color is pure white and unmarked. The 

 measurements of 50 eggs in the United States National Museum aver- 

 age 16.0 by 12.0 millimeters; the eggs showing the four extremes meas- 

 ure 17.3 by 12.7, 17.0 by 12.7, 14.4 by 11.3, and 15.2 by 11.2 millimeters. 



Yoimg. — The period of incubation has been stated as from 12 to 14 

 days, and is apparently performed by the female alone. Dr. 

 Walkinshaw (1935) writes: 



The young of the Marsh Wren remain in the nest from 12 to 14 days. They are 

 fed by the female almost entirely but the male occasionally will stop to feed 

 them. Excreta are carried away by the mother bird on her feeding trips to the 

 nest. 



When the weather was very warm, the young peered out througli the opening, 

 breathing very fast with mouths wide open. They showed little fear of man 

 until they were about 12 to 14 days old, then when one approached the nest they 

 watched very dubiously. 



After they leave the nest the young move about among the sedge and bushes of 

 the marsh like little mice, except that they occasionally move up to secure food 

 from their parents which feed them until they are able to take cai'e of them- 

 selves, even then they move about in small groups until migration time. 



At the nest watched by Mr. Mousley (1934), "altogether, the young 

 were fed 28 times in the 6 hours, or at the rate of once in every 13 min- 

 utes, and this by the. female alone, her partner contenting himself by 

 always singing from his favourite station on the thorn bush, whenever 

 she approached the nest." 



Several observers have stated that two broods are raised in a sea- 

 son. Fresh eggs have been found at such early and late dates that 

 this seems to be indicated. 



Plumages. — I have not seen the natal down. Dr. Walkinshaw 

 (1935) describes some very young birds as follows : 



The young have legs and bill pink, the latter a little darker near the tip of 

 the maxilla. The young when they leave the nest are from 55 to 70 mm. in 

 length. The top of the head on one specimen of 58 mm. in length, had no 

 stripes, being dark brown changing to a lighter brown on the forehead. The 

 back, rump and upper tail coverts were uniform hair brown, the wings a deeper 

 brown, and the breast very similar but a little lighter, than that of the adult. 

 The tail was 10 mm. in length, hair brown with one black band about two mm. 

 in width at the tip. A bird 66 mm. in length had the coloration much the same, 

 but there were indications of black on the wings and nape. In a bird 69 mm. 

 long the head was colored the same, but the wings were barred with blackish and 

 tipped with brown, and the back was barred with black. The breast on the 

 sides was much more bnffy and had a distinct band near the throat. The bills 

 were decurved in these young birds. 



