THE BARN SWALLOW. 



255 



here is hardly needed. About the 10th of May, after the 

 birds have paired, they commence building; or sometimes 

 the same couple begin repairing the nest of the preceding 

 year or years, as the same nest 

 is occupied several seasons. It is 

 built in the eaves of houses or 

 barns, or on rafters of barns and 

 other buildings. It is constructed 

 outwardly of a strong shell of 

 pellets of mud, wdiich are plas- 

 tered together, and, as Nuttall 

 says, " tempered with fine hay, 

 and rendered more adhesive by 

 the glutinous saliva of the bird." This nest is built out 

 and up until the top is about horizontal, and then lined with 

 a layer of fine grass or hay, which is covered with loose 

 feathers. This bird is fond of society, often as many as 

 twenty nests being in the same eaves. The eggs are 

 usually four in number, sometimes five : they are of a 

 nearly pure-white color, with a slight roseate tint ; and are 

 spotted more or less thickly with fine dots of two shades of 

 brown, reddish, and purplish. The dimensions of four eggs, 

 collected in Upton, Me., are .76 by .56 inch, .70 by .52 

 inch, .76 by .52 inch, .69 by .53 inch. The largest speci- 

 men, in a great number, is .78 by .57 inch ; the smallest, 

 .67 by .50 inch. Two broods, and sometimes three, are 

 reared in the season. The period of incubation is thirteen 

 days. 



About the first week in September, the old and young 

 birds of different families gather in immense flocks ; and, 

 after remaining about the marshes near the seacoast for a 

 few days, they leave for their winter homes. It is seldom 

 that any are seen after Sept. 15tli in New England. 



