NORTHWESTERN SHRIKE l29 



the breeding range, that 1 am disinclined to use diiferent names for 

 the variations exhibited." 



Dr. Alden H. Miller (1931) does not agree with the above, saying: 

 "I cannot agree with Swarth (1926, pp. 135, 13G) that it is impossible 

 to define the boundary between the eastern and western races of this 

 species, difficult as it is to identify some winter specimens. The boun- 

 dary line between the breeding ranges is poorly knovvn, I believe, only 

 as a result of the extremely meagre collections of breeding birds from 

 critical localities." 



His distributional map shows an area of intergradation from the 

 west coast of Hudson Bay westward for breeding birds, and directly 

 southward from that area into the United States for wintering birds. 

 It is interesting to note that this is just where one would expect to find 

 the intergrades that Mr. Swarth had difficulty in identifying! He 

 says that "an immature specimen from Fort Churchill, Manitoba, 

 taken in July may be considered intermediate between the two races 

 although its dimensions are those of invictus.''^ This seems to demon- 

 strate, as satisfactorily as our present knowledge will allow, that in- 

 victus is the breeding form from this point westward. 



Nesting. — Neither Dr. Grinnell nor Mr. Swarth found a nest of this 

 shrike, but Roderick MacFarlane (1908) took a fine nest of the north- 

 western shrike at Fort Anderson, northern Mackenzie, on June 11, 

 1863 ; it was in a spruce tree, 7 feet from the ground ; he describes it 

 quite fully, as follows : 



It is in many respects in striking contrast with the nests of its kindred species 

 of the Southern States of the Union, far exceeding them in its reh^tive size, in 

 L'lahorate finish, and warmth. It is altogether a remarkable example of what 

 is known as felted nests, whose various materials are most elaborately matted 

 together into a homogeneous and symmetrical whole. It is seven inches in diam- 

 eter and three and one half in height. The cavity is proportionately large and 

 deep, having a diameter of four and one-half inches and a depth of two. Except 

 the base, which is composed of a few twigs and stalks of coarse plants, the nest is 

 made entirely of soft and warm materials most elaborately iuterworked together. 

 These materials are feathers from various birds, fine down of the eider and other 

 ducks, fine mosses and lichens, slender stems, grasses, etc., and are skilfully and 

 artistically wrought into a beautiful and symmetrical nest, strengthened by the 

 interposition of a few slender twigs and stems without affecting the general felt- 

 like character of the whole. 



Several nests have been reported, from the more southern portions 

 of Canada, as placed in deciduous trees, but these were probably extra 

 large nests of white-rumped or migrant shrikes. 



There is a beautiful nest of this shrike, taken by Johan Koren in 

 Alaska on May 21, 1913, in the Thayer collection in Cambridge. It is a 

 bulky nest, nearly 9 inches in external diameter and about 4 inches in 

 height ; the inner cup is over 4 inches in diameter and 2i/^ inches deep. 

 It is made of coarse grasses and weed stalks, inner bark, and plant 



