1874.] MR. R. B. SHARPE ON CERTAIN ACC1PITRES. 581 



fordshire along with the nest and eggs ; and the female of this bird 

 wears such a curious plumage that I have thought it worthy of being 

 brought before the notice of the Society. She is fully adult, having 

 been, indeed, trapped on the nest, but has almost the tail of a male 

 bird, blue with a few black bars. My views on the relation of the 

 British avifauna to that of the continent of Europe are, I believe, now 

 so well known that I shall be excused for bringing forward this female 

 Kestrel as a further evidence of the tendency of our indigenous birds to 

 show the effects of their insular habitat, of which Parus britannicus 

 and Acredula vagans are forcible examples. For I may as well state 

 that my faith in these last-named species is not in the least shaken, 

 despite the cheers for a " conservative reaction " given by Dr. 

 Sclater ('Ibis,' 1874, p. 173) on account of Professor Newton's 

 refusal to recognize, in his edition of 'Yarrell,' the specific titles 

 bestowed on the British Titmice. I am thankful to say that all 

 the continental naturalists to whom I have shown the birds are 

 more " liberal " in their tenets —and naturally so ; for neither Pro- 

 fessor Newton nor any one else has yet recorded an olive-backed 

 Coal Titmouse from the continent of Europe ; and however nearly 

 Parus britannicus in its worn breeding -plumage may approach the 

 blue-backed P. ater, birds killed in autumn, winter, and spring can 

 scarcely be mistaken for that species. 



Returning once more to Cerchneis, I notice that the discovery of a 

 female of C. tinnunculus with a blue tail renders invalid the charac- 

 ters which I have assigned to the hen C. rupicola in my ' Catalogue 

 of Birds ; ' and it therefore becomes necessary to reexamine the two 

 species, to establish, if possible, a permanent character between them. 

 In Dresser's * Birds of Europe,' when I was part author, the Com- 

 mon Kestrel was described and figured ; and we then had occasion to 

 remark on the dark form of Kestrel which occurs along the southern 

 range of C. tinnunculus, from Madeira through Senegambia to 

 Abyssinia, in the Himalayas, China, and Japan. At p. 426 of the 

 ' Catalogue ' I again draw attention to this dark form : and I may 

 be allowed to quote a few remarks I make there on the plumage 

 of the female : — " Through all these dark races of Kestrel one 

 character is predominant in addition to the richer and more in- 

 tense coloration of the male bird, viz. that the female has more or 

 less of a shade of blue on the rump and tail, which sometimes over- 

 spreads the whole of the latter." The Hertfordshire female, how- 

 ever, differs from those alluded to in the above paragraph in having 

 an entirely blue tail regularly banded across with black, and the 

 rump also blue with a few black shaft-streaks. And if any one takes 

 this specimen for elucidation by means of the " Key to the Species " 

 of Cerchneis (p. 423), they will find that it will appear as an adult 

 female of Cerchneis rupicola, the South-African Kestrel, and is 

 further closely allied to that of C. moluccensis. That a hen bird 

 killed in England along with an ordinary male Kestrel can be either 

 one or the other of these species is impossible ; but we may look 

 upon it as exhibiting a tendency to vary in our indigenous species in 

 the same wav as the Madeira bird does in a more southern latitude. 



