Least Bittern. 329 



cation; I have visited their resorty in May at various 

 times and failed to find them nesting in that month, and 

 even in the early part of June, and again I have found 

 their nests soon after the middle of May. Like most of 

 the swamp birds, they do not in general begin to nest 

 until the water has subsided to its ordinary level, usually 

 waiting for signs that the water is receding permanently, 

 though they are frequently deceived and lose their habita- 

 tions by late freshets. They choose sites among the flags 

 in the inner part of the fringing growth, where the water 

 is deepest. I have never found their nests in the shallow 

 parts of the swamps. The foundation of the nest is a thin 

 tuft of flags. Between the upright culms short pieces of 

 dried stems are piled, the base of the accumulated mate- 

 rial being in most instances above the water. The mass 

 is generally held in place by the inward pressure of the 

 culms, and is usually somewhat protected laterally by the 

 surrounding stems, frequently above by the drooping tops 

 of the flags. The nest is a substantial platform, with a 

 slight cavity, in most instances standing from six to ten 

 inches above the water, and over six inches in average 

 width across the top. Sometimes a nest is more hastily 

 made, the pile of material being only three or four 

 inches thick, and fastened to the stems by entwining the 

 soft dried pieces about the upright supports. 



Mr. Nelson *' always found its nest supported at from 

 two to three feet above the water;" but in the swamps 

 where my notes were taken the birds nest lower, as I 

 measured the height of every nest I examined, and found 

 none as high as two feet above the water. The usual 

 complement is four eggs. Frequently sets of five are 

 found, and many nests contain only three eggs, the smaller 

 complements being found in late nests. In rare instances 

 sets of six eggs are found. The eggs are pale greenish 

 blue, or greenish white, rather elliptical in outline. They 

 have a close resemblance to the eggs of the yellow-billed 

 cuckoo, yet have a lighter tint. They are a trifle over 

 1.20 inches in length and about .95 in width. 



The least bittern sometimes reveals the site of its nest 

 by flying from it at the approach of an intruder. Accord- 

 ing to my observations of its habits, it leaves the nest 



