

When the nesting grounds are reached, the routes branch again and again to 



accommodate each small band until every pair has finally 



gained its own home range. 



Bagg and his colleagues (1950) point out that favorable arrangement of 

 the high- and low-pressure areas, "while always of major significance in 

 spring, may be less absolute in character during the later part of the spring 

 migration than during the early part." It is thus interesting to observe that 

 while in late April and early May there was some migration almost every 

 day, the second biggest waterfowl movement of 1954 left Delta on the eve- 

 ning of May 4, the second time in 1954 when there was the east-west oppo- 

 sition of the high- and low-pressure areas in Canada. The third big rush of 

 waterfowl, which carried the Swans, Richardson's Geese, and wavies away 

 from Delta, occurred on May 10 and 11, when the high and low next opposed 

 each other favorably. 



The grand movement of ducks into the northwest observed at Delta, is, 

 in effect, a major "trunk line" of waterfowl. Great masses of travelers go 

 together, despite their division into small flocks, in the general direction of 

 their destination. But it cannot be that these birds are swept along with 

 this movement; each must bend away from the main stream at the correct 

 time and place for turning. Some Redheads, for example, reach their Minne- 

 sota stopping place together en route from the Atlantic Coast, but those 

 destined for Delta must now go differently from companions traveling to- 



120 



