1905.] HYBRIDS AMONG NORWEGIAN BIRDS. 13 



hybrids of known descent) that the smaller species {T. bonasia) 

 is the father (see further on, p. 26). 



From T. bonasia this (male) form has inherited the slightly 

 lengthened crown-feathers, which can probably be raised likeacrest, 

 as also the comparatively great length of the tail, the centre tail- 

 feathers being considerably longer than half the wing-length. It 

 has further inherited from that species most of its colouring, the black 

 throat in particular, surrounded by white, being almost exactly 

 like that of the hazel-grouse. The centre pair of tail-feathers 

 are also finely mottled, and there is no white area on the wing. 



From the black-game (L. tetrix) it has inherited the number 

 of the tail-feathers. The form of the tail, moreover, in this 

 male, is almost exactly like that in the grey-hen, while its 

 chief colour more nearly resembles that of the blackcock. The 

 markings of the body, the general absence of brownish red, and 

 the conspicuous black colour that takes its place, are also in- 

 herited from the blackcock. 



The above-mentioned two specimens, both males, are the 

 only ones of this hybrid form that have up to the present been 

 found in Norway. In Sweden a single specimen, also a male, 

 was killed in Westergotland in November, 1890, this bird being 

 somewhat lighter in colour 1 . Several specimens have moreover 

 been found in northern Russia. 



The testes in the specimen from Rånen were well developed, 

 conparatively large, and to all appearance not malformed. The 

 left had a length of 6 mm , the right of 5 mm . 



Food. The stomach of the first specimen (from 1876) con- 

 tained, according to Mr. Dresser, a catkin of Betula and other 

 vegetable substances, besides some coarse grains of quartz. In 

 the new specimen the stomach was quite full of juniper berries, 

 and a quantity of tips of Betula odorata branches. 



1 Kolthoff, Bih. till K. Svenska Vet.-Akad. Handl. B. 17, Afd. IV. No. % 

 with plate. (Stockholm, 1891). 



