PASSERINE BIRDS FOUND MIGRATING IN MOULT 249 



feathers were new, the rest old and worn ; primaries worn, 

 secondaries fresh. A male Sedge-warbler killed at the Isle 

 of May lantern on 8th August 1910 had evidently begun to 

 migrate before moulting, as all the feathers, including the 

 quills, were old and very much worn. 



Professor Newton in his article on Moult {Dictionary of 

 Birds, p. 598) writes : " the Garden-warbler, Sylvia salicaria, 

 and the Whitethroats, vS. rufa and 5". cumica, are said to 

 moult twice in the year." We have examined a fair series 

 of all three species, and found all the autumn birds in fine 

 fresh plumage, except one Garden-warbler (9, Fair Isle, 

 15th September 1905), which had a good many feathers on 

 the head, back, and rump in quill, and two Common White- 

 throats from Fair Isle, one of which (15th September 

 1906, 9) had the 2nd, 3rd, and 4th primaries in both wings 

 still partly in quill, the old 2nd primary in the right 

 wing still remaining, a good many of the tail feathers still 

 partly in quill, and outer ones not fully grown ; the other 

 (9th October 1906) having the outer tail feathers on the 

 left side not fully developed. 



With regard to the spring specimens, there would appear 

 to be considerable differences between the species, and even 

 between individuals. All the spring Garden-warblers were 

 in beautiful plumage, none of the feathers, including the 

 remiges and rectrices, showing signs of wear. A female 

 from the Isle of May on 15th May 191 3 had an imperfectly 

 developed tail, all the feathers with the exception of the 

 four outer feathers on the right side being only partially 

 grown. There is much more variation between individual 

 Whitethroats : to take the common species first, we have 

 examined sixteen spring specimens, and find that five are 

 freshly moulted birds in beautiful plumage, the wing and 

 tail-quills showing hardly any signs of wear; while three 

 are in an extremely worn condition, the feathers of the tail 

 being worst. These very worn specimens were on passage 

 as late as 24th May. If these were to be breeding birds, it 

 is difficult to see when they would have time to accomplish 

 even a partial moult before beginning to nest. In addition 

 to these we have two freshly moulted Whitethroats, with 



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