80 THE WARBLERS 



mystery, the nest was deserted, and a second one was found half-built 

 within a few feet three days later. The new nest contained three 

 eggs on the 23rd and five on the 26th. Ten days later this nest had 

 been destroyed and a third one partly built. Then there intervened 

 a week of continuous heavy rain which apparently drove the marsh- 

 warblers to temporarily abandon nesting operations, after which they 

 built a complete new nest on the top of the one last constructed, but 

 for some undiscovered reason abandoned it. 



The eggs of the various species forming the group show fairly 

 good specific characters. Those of the marsh-warbler more nearly 

 resemble eggs of the great reed-warbler than of the reed-warbler. If 

 there is any approximation between the reed-warbler and the marsh- 

 warbler, it is when the former species produces eggs which it does 

 occasionally with pale grey blotches on an almost white ground ; but 

 I have seen none with the small dark spots characteristic of the 

 marsh-warbler. 



The incubation period of the whole group is about thirteen or 

 fourteen days. Mr. Warde Fowler gives fourteen or fifteen days for 

 the marsh- warbler. 1 The females do the greater part of the incubat- 

 ing, the males relieving them for a few hours during the day. 



I have watched reed- and sedge-warblers feeding their young in 

 the nest, and like all insect-eating birds their visits are frequent, 

 food being brought at intervals of two or three minutes, the males 

 bearing a full share of the task. Both species not only collect insects 

 from the herbage and the ground but also catch them on the wing. 

 I have several times seen reed-warblers feed their nestlings with 

 small dragon-flies. These are crammed, wings and all, into the mouths 

 of the young birds. The fseces of the nestlings are removed from the 

 nest by the adults, sometimes swallowed, but generally carried away 

 and dropped. 



The young of all the Acrocephali leave the nest early, often before 

 they can fly, and show considerable agility in climbing among the 



1 Zoologist, 1906, p. 408. 



