1905.] HYBRIDS AMONG NORWEGIAN BIRDS. 5 



2. Turdus merula, Lin. X Turdus pilaris, Lin. 

 (mas?) (fem.?) 



Occurrence. One specimen caught in Vestre Aker, Dec. 1863. 



Diagn. Male. The upper surface almost as in T. pilaris: 

 lower parts chiefly black, each feather with a lighter margin, narr om 

 on the br east, broader on the sides and abdomen. The under wing- 

 coverts greyish black with lighter edges; the under tail-coverts almost 

 pure black, with narrow reddish grey margins. Feet dark brown. 



One specimen. In the Christiania Museum there is a spe- 

 cimen which I found among a number of T. pilaris caught in 

 Vestre Aker on Dec. 8 th , 1863. Assuming that the mother was 

 a T. pilaris, this bird (like the preceding hybrid) has attemp- 

 ted to winter with its mother, whereas its other parent, T. merula, 

 is a normal migratory bird in Norway 1 . 



The colour of the upper surface in this specimen is nearly 

 as in T. pilaris, but of an almost imperceptibly darker shade. 

 The lower parts are blackish; the breast is almost perfectly 

 black (with a shade of brown), and with extremely narrow 

 transverse margins, these being rather broad on the abdomen 

 and sides, and of a whitish or reddish-grey colour, thus recal- 

 ling the markings on the under parts in T. torqualus in its au- 

 tumn plumage. The feathers about the vent are white; the bill 

 is brownish black, as are also the feet, although lighter along 

 the margins of the upper mandible and at the root of the under 

 mandible. 



Assuming that in both these hybrid forms T. pilaris has 

 been the mother, we thus find that her colour is retained to a 

 greater or less extent in their upper surface, while the lower 

 surface (with the under tail and under wing coverts), which 

 presents a combination of the markings of both parents, has 

 derived most from the father. 



1 The specimen was mentioned by me in 1864 and 1871 as „an imper- 

 fect melanism" (Nyt Mag. f. Naturv., Vol. 13, p. 288 & Vol. 18. p. 163. 

 Christiania 1864 & 1871). 



