1.5() HKITISH HIKDS. [vol xv. 



RAPID RE-BUILDING BY BONELLI'S WARBLER 

 AND TITS. 



With reference to Mr. Musselwhite's note {antea, p. 140) 

 on rapid re-nesting of a Whitethroat {Syh>ia c. comnmnis), 

 after having had a chitch of considerably incubated eggs 

 removed, I think an experience I had in Spain in 1920 may 

 be of interest. On May i6th I found three nests of BonelH's 

 Warbler {Phylloscopus bonellii), each containing five eggs, 

 two lots proved to be nearly hatching, and the third was 

 very much incubated. During the next three days I found 

 all three pairs very busity re-building within a few yards 

 of their respective first nest sites. 



On May 23rd each nest contained one egg and incubation 

 commenced with four, five and five eggs respectively on 

 May 26th and May 27th. 



The period in one case was therefore ten days, and in the 

 other two cases eleven days. The time period is, I know, 

 not exceptional, but interesting points are that the first 

 clutches were nearly hatched when taken, and all three pairs 

 of birds behaved in exactly the same way to a day. 



W. M. CONGREVE. 



As showing the extremely short period which elapses before 

 a bird whose nest has been taken or destroyed begins to nest 

 again, the following incident which was witnessed by Major 

 W. M. Congreve and myself in Marocco, may be of interest. 

 On April 26th, 1920, we had taken a nest with ten eggs (in 

 which incubation had begun) of the Ultramarine Tit {Parus 

 ccendcHS iiltramarinus) from an old Woodpecker's boring in 

 a cork oak. While sitting close at hand and examining the 

 structuie of the nest, we noticed the hen making journeys to 

 and from the nest-hole, and satisfied ourselves by watching 

 with glasses that she was carrying fresh nesting material 

 into the hole within a few minutes of the removal of the 

 original nest. F. C. R. Jourdain. 



RAPID RE -NESTING OF THE COMMON 

 WHITETHROAT. 



With reference to Mr. Musselwhite's note {antea, p. 140) 

 the normal nest of this bird {Sylvia c. commimis) is built 

 very quickly though I have no records at hand, but (in this 

 district at least) large numbers of " cock's " nests are built 

 by unmated males, as I wrote in the Irish Naturalist of 

 October-November, 1918. Several may be built by the 

 ?ame bird before he gets a mate, if ever. These nests have 



