BRITISH WARBLERS 



imitated as far as it lay in my power to distinguish 

 them, and the results plainly show a lack of any definite 

 sequence. Two examples will suffice to illustrate my 

 meaning. In the first case the imitations were produced 

 in the following order: Sparrow, Blackbird, Whitethroat, 

 Sedge Warbler, Sparrow, Whitethroat, Green Woodpecker, 

 Blue Titmouse, Redstart, Blackbird, Whitethroat, Green- 

 finch, Swallow, Whitethroat, Blackbird, Swallow, Chiff- 

 Chaff, Hedge Sparrow, Blue Titmouse, Swallow, Greenfinch, 

 Sparrow, Greenfinch, Green Woodpecker, Blackbird, Sparrow, 

 Whitethroat, Chaffinch, Starling, Thrush, Hedge Sparrow, 

 Blue Titmouse, Whitethroat, Swallow, Sparrow, Thrush, 

 Whitethroat, Hedge Sparrow, Blue Titmouse, Whitethroat, 

 Greenfinch, Willow Warbler, Thrush, Hedge Sparrow, Green 

 Woodpecker. And in the second as follows : Blue Titmouse, 

 Swallow, Sparrow, Swallow, Blue Titmouse, Greenfinch, 

 Blackbird, Willow Warbler, Sedge Warbler, Chaffinch, Pied 

 Wagtail, Nightingale, Starling, Blue Titmouse, Sparrow, Red- 

 start, Starling, Sedge Warbler, Sparrow, Swallow, Chaffinch, 

 Whitethroat, Swallow, Starling, Greenfinch, Willow Warbler. 

 There is nothing in the nature of a uniform sequence here ; 

 the most that can be said is that in certain instances 

 imitations of the same two species are to be found in 

 the same sequence. It must not be supposed that the above 

 imitations were produced in a continuous stream unbroken by 

 the true song of the species. Even when the bird is in an 

 imitative vein it would, perhaps, be more correct to speak of 

 imitations being intercalated among phrases of the song, than 

 of phrases of the song being intercalated amongst extraneous 

 imitations. Both the males were, singing in Worcestershire 

 about 2.30 a.m., and whilst the imitations were being pro- 

 duced the majority of the birds copied uttered no sound 

 within hearing; some would probably not have been astir 

 at that hour of the morning. It is evident, therefore, that 

 there is mental retention and revival of some kind ; for it 

 must be borne in mind that it is not only an alien note that 



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