MARSH-WARBLER IN CAMBRIDGESHIRE. 43 



the scolding of a pair of Sedge- Warblers suggested that 

 it belonged to that species. But it was so far from the 

 ground and so clearly suspended that I could not feel 

 satisfied until I had concealed myself in a bush, and seen 

 the Sedge-Warbler come and feed the young. A week 

 or so later, when these young birds had flown, and all 

 hopes were at an end that the Marsh- Warbler would lay 

 in the double nest, I took photographs of both nests 

 and also brought them away. 



So far as I could determine there were no more than 

 the one pair of Marsh-Warblers in this copse, and I do 

 not think any young were brought off, unless while I was 

 keeping the double nest under observation they were 

 keeping house in another nest. 



I have, perhaps, given this account at greater length 

 than its importance deserves, but my very natural desire 

 to obtain photographs of the Marsh- Warbler led to my 

 spending a considerable time in the willow-copse, and 

 incidentally learning much that was new to me of the 

 nesting-habits of all three species of Acrocephalus, e.g., 

 the suspended nest of A. phragrnitis, and a small colony 

 of A. streperus nesting a hundred yards from the river 

 in the branches of smaU pollarded willows and in ten feet 

 high osiers. 



So far as A. palustris is concerned, the interesting points 

 are : — The locality is in the district where Bond lived 

 and, no doubt, found the nest recorded in Howard 

 Saunders' Mayiual ; the first nest, found in June, 1909, 

 contained a Cuckoo's egg ; a second nest was begun 

 four days later and an egg laid in it a week after ; and 

 the curious fact of the double nest. The fate of the first 

 nest, from which the Cuckoo's egg was taken, and why 

 the birds left it remain a mystery. Their building another 

 nest so soon after and so near the same spot is, according 

 to other observers, a normal habit, as I have seen it 

 stated, and quote from memory, " If a nest is robbed 

 or destroyed the birds at once build again close to the 

 same spot." 



