NON-INDIGENOUS BRITISH BIRDS. 201 



Breeding habits: In the northern portions of its 

 distribution the American Bittern is a migrant, leaving 

 in autumn and returning in April and early May. It 

 is a shy, skulking, solitary species, much more often 

 heard than seen, and keeping close to the dense cover 

 of the haunts it frequents. Of the pairing habits of this 

 Bittern nothing apparently is known. Its favourite 

 nesting haunts are marshes and swamps and the dense 

 belts of aquatic vegetation round the more open waters. 

 Much difference of opinion prevails concerning the nest- 

 ing habits of the American Bittern. Some writers assert 

 that the bird breeds in colonies, others that it lives in 

 solitary pairs. There can be no question, to my mind, 

 that the latter view is the correct one. The nest is made 

 in the swamps, either on the ground amongst the aquatic 

 vegetation, or more frequently amongst the rushes in 

 shallow water a little distance from the shore. It has 

 been said that the nest is built in trees and bushes, and 

 that the eggs are laid on the bare ground or under a 

 bush, but all these statements may, I think, be safely 

 discarded. The nest is a large bulky structure, more 

 than a foot in height, and composed of half-rotten sedges 

 and rushes, the saucer-like cavity at the top being lined 

 with the driest and finest material. The bird is a close 

 sitter, and when flushed, hurriedly leaves the nest and 

 seeks seclusion in the nearest cover. 



Range of egg colouration and measurement: 

 The eggs of the American Bittern are usually four or 

 five in number, but it is said that seven are exception- 

 ally found. They are uniform brownish-olive or buff. 

 Average m.easurement, 2*0 inches in length, by v^ inch 

 in breadth. The duration of the period of incubation is 

 unknown, also which parent performs the duty. 



Diagnostic characters: The eggs of the American 

 Bittern are not easily confused with those of any other 



