OPEN NESTS 161 



in wetter spots the nest is said sometimes to be a foot 

 or more in height. Montagus Harrier (C. cineraceus), 

 a bird living on heaths and moors, makes a scanty 

 nest like the first named type of that of the Hen 

 Harrier. Lastly, the somewhat aberrant Ospreys 

 (Pandioninse) build enormous eyries, placing them in 

 trees (as is especially the case in North America), or 

 on cliffs or ruined buildings. Many of the nests are 

 the accumulation of years, and consist of huge stacks 

 or piles of sticks as much as four feet high and as 

 many broad, intermixed with turf and lined with fine 

 twigs and grass, much of the latter in a green state. 

 The cavity containing the eggs is shallow and about 

 twelve inches in diameter. This latter bird builds in 

 societies in North America, but unfortunately it is far 

 too rare in our islands now for such an indulgence in 

 social instincts. As said before, perhaps the most 

 remarkable feature in the nesting arrangements of 

 Raptorial birds is the frequency of the green lining. 

 This lining, judging from the fresh state in which it is 

 usually found, seems to be renewed as required. Its 

 use appears to be totally unknown to naturalists. 

 The same habit has also been alluded to when we 

 were dealing with the nests of the Cormorants. 



As we have already seen, most of the birds com- 

 posing the order Coraciiformes are either nestless, 

 build crude nests, or conceal them in a variety of 

 ways. There are, however, certain important excep- 

 tions to this rule in one of the families (the Humming- 



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