the interior of California to the mouth of the Colorado River and on to 

 winter quarters in western Mexico (Fig. 18, routes 6 and 7). 



The movements of the western tanager show a migration route that 

 is in some ways remarkable. The species breeds in the mountains 

 from the northern part of Baja California and western Texas north to 

 northern British Columbia and southwestern Mackenzie. Its winter 

 range is in two discontinuous areas southern Baja California and 



P 6' 



& 







r-L r ' ^r 'WM>r 



i T S v--< T \ r 

 i i } \ IH^ 



' -f- -rl -V-'-^ 7 " 



Figure 21. The breeding range, wintering range, and main migration route of Ross' 

 geese. This is the only species of which practically all members breed in the Arctic, 

 migrate south through the Canadian prairie, and upon reaching the United States, 

 turn to the southwest rather than the southeast. The southern part of this route, how- 

 ever, is followed by some mallards, pintails, wigeons, and other ducks. 



77 



