1921.] Letters, Extracts, and Notes. 755 



Nestling Plumages of Owls. 



Sir, — Mr. Witlierby^s letter re the above (' Ibis/ p. 567) 

 has caused me to go into the matter aj^aiu. 



Mr. Witlierby writes : " I cannot agree Avith Mr. Bonhote 

 that the Eagle-Owl has three generations of plumage before 

 acquiring feathers like those of the adult. ... I find . . . 



that the first down is immediately succeeded by the juvenile 

 plumage. . ... . The specimens in the British Museum 



clearly show the shortish white down attached to the tips of 

 these downy feathers." 



I have examined these same specimens in the Museum^ 

 and find that "downy feathers" of the juvenile plumage 

 and the down of the second plumage both carry the shortish 

 white down at their tips. 



The second down plumage has also been rioted by two 

 other observers — (1) Mr. Gurney, ' Zoologist,' 1849, p. 2567 ; 

 (2) M. Lavauden, 'Revue Fraufalse d'Oruithologie,' May 

 1920, p. 60. 



The first point to be considered is the chronological 

 sequence and age at which these plumages sliow. Mr. 

 Gurney^s notes and mine exactly coincide. Mr. Gurney 

 writes that the young were hatched on 19 May and covered 

 with a whitish down ; at three weeks old they assume a 

 second down, and the first feathers (? quills, J. L. B.) began, 

 to appear at five weeks ; on 23 July they could fly to tlie 

 perches. 



My birds were liatched on 25 May ; on 21 June (three 

 weeks and five days) they were covered with a huffish 

 down ; on 3 July (five weeks) the quills were just showing ; 

 on 8 August they could fly, and they were in adult dress 

 by 6 September. 



There can therefore be no doubt whatever that the Eagle- 

 Owl has three distinct plumages before assuming its first 

 winter plumage. The point, then, is how can these plumages 

 be morphologically interpreted, in view of the fact that, as 

 Mr. Witherby points out aiul in which I concur, the juvenile 

 (third) plumage bears the first white down on its tips, as 

 docs also the second down plumage. 



