SOMETHING ABOUT BIRDS [13] 



Another interesting map (Figure 2.) shows the returns of Cackling 

 Geese banded near the mouth of the Yukon River, Alaska, chiefly in the 

 vicinity of Hooper Bay. These birds have a very restricted breeding area 

 and migration route. Captured birds bearing these bands have come from 

 the coasts of Alaska, British Columbia, and Washington. The birds 

 follow the coast to the mouth of the Columbia River or to Tillamook 

 Bay and there turn inland, heading directly for Tule Lake on the Oregon- 

 California border east of the Cascades. They remain at this favored spot 

 until freezing weather forces them south into the Sacramento Valley, 

 where they spend the rest of the winter. In spring the route is reversed. 



There have been many explanations advanced to account for the fixed 

 migratory habits of so many species of birds. Those interested will find 

 the various theories outlined and discussed in ornithological literature. 



FIGURE i.- Distribution of returns from ducks banded in Oregon. 



