1905.] HYBRIDS AMONG NORWEGIAN BIRDS. 19 



in Skjerstad (east of Bodø) at the end of April, 1893, which 

 still wears its winter garb. 



The winter plumage is assumed by young birds during Oc- 

 tober. As early as the 7 th October (1876), a female in full 

 winter plumage was shot at Røros; whereas specimens may 

 occasionally be met with as late as November, still in their 

 moulting stage. A male specimen in the Christiania Museum, 

 caught in Sande district on the 9 th November, 1881, still has 

 the young bird's last brown feathers in the nape. 



The spring and summer plumages are still almost unknown 

 in Norway. A single female specimen, caught in Inderøen in 

 October, 1892, is clothed, as mentioned above, in a strangely 

 variegated garb, with broad reddish yellow cross bars and barred 

 tail-feathers, which must be considered as part of the female's 

 summer plumage; while at the same time the first indications 

 of the winter plumage are visible. 



The Christiania Museum also possesses a young bird still 

 wearing in the main the plumage of the chick, although it has 

 attained the size of a small L. lagopus. This bird was caught 

 in Odalen in the autumn (probably September) of 1880. 



From its father (L. lagopus, mas) the Rype-Orre has in- 

 herited its comparatively long naked claws and short hind toe, 

 while from its mother (L. tetrix, fem.) it has inherited the short, 

 pendant, pectiniform scales at the sides of the last (naked) 

 toe-joint. 



In its winter plumage, the Rype-Orre has tåken the colour 

 of most of the under surface from its father; but in all the 

 white parts, the feathers are brownish black at the base, both 

 in male and female. The colour of the upper surface, on the 

 other hand, is rather derived from the colour in black-game. 



Hdbits. Most of the specimens concerning which direct 

 observations have been made, have been caught in ptarmigan- 

 snares on the mountains, or shot among the ptarmigan there. 

 These snares are set in the highest parts of the birch-woods 

 on the mountain-sides, where grouse (of both species) congregate 



