HUDSONIAN SPRUCE GROUSE 125 



breast. This molt is complete except for the two outer primaries on 

 each wing. It begins on the breast, extends to the flanks and back, 

 and is finally completed on the throat and crown. When this molt 

 is completed in October, young birds can hardly be distinguished 

 from adults, though there is more white in young birds and the outer 

 primaries are diagnostic. 



Adults probably have a very limited prenuptial molt about the 

 head and neck in spring; and they have a complete postnuptial molt 

 in August and September. The Hudsonian spruce grouse is a grayer 

 bird than the Canadian, with rather more white and purer gray in the 

 male ; the difference is even more pronounced in the female, which is 

 much more purely black and gray, with much less buffy or ochraceous.] 



Food. — The spruce grouse not only lives in spruce woods but 

 depends upon the buds, tips, and needles of the spruce, as well as 

 of the fir and larch, for a considerable part of its diet. This is 

 particularly the case in winter when snow and ice cover the ground, 

 concealing many berries, which it enjoys eating in summer. In the 

 latter season, I have found in Canadian Labrador the following 

 stomach contents of this bird : A young able to fty had eaten 5 red 

 spiders, 10 green snowberries, and 75 achenes of a bulrush (Scirpus 

 caespitosus) ; an adult had eaten 25 snowberries, 20 crowberries 

 (Empetrum nigrum), and many leaf tips of a dwarf bilbern^ 

 {Vaccinium ovafolia). Another adult had been feeding entirely on 

 crowberries and a third had "been eating the leather woodfern 

 (Dryopteris marginalis). Bearberries (Arctostaphylos uva-ursi), 

 as well as grass and weed seeds and various insects, including grass- 

 hoppers, are also eaten in summer, although the regular diet of 

 spruce is not entirely given up. 



E. A. Preble (1908) found nothing but spruce needles in the 

 stomachs of four spruce grouse. Another, taken on the shore of an 

 inlet had in its crop several mollusks (Lymnoea palustris). The 

 crops of a number taken late in fall and in winter contained only 

 the needles of the jack pine {Pinus banksiana). A young bird 

 just ready to fly had eaten bits of the American rockbrake fern 

 {Cryptogramma acrostichoides) , blueberries {Vaccinium uligi- 

 nosum), and mountain cranberries (F. vitisidaea) . 



Lucien M. Turner says : 



The food of the spruce partridge consists of the tender, terminal buds of 

 spruce ; and this, in winter, seems to be their only food * * * mixed with, 

 at times, an astonishing quantity of gravel. I was surprised to find these 

 stones of such uniformity of size and material. Crystallized quartz fragments, 

 in certain instances, formed alone the triturating substance. 



If a bird be opened when just killed the contents of the gizzard has a 

 powerful terebinthine odor which quickly pervades the flesh and renders it 

 uneatable to a white person. In the spring and summer months these birds 



