TBUMPETSB swan. 87 
southern Iowa, on the average, March 1'.': at Heron Lake Minn.. (In- 
average date of arrival is April k, earliest March 21, I vs '* (a very 
early spring); other average date- are: Nebraska, March L6; South 
Dakota, April 2; North Dakota. April L5; Saskatchewan, April L6; 
British ( Columbia about April 20. All these dates are later than those 
which mark the arrival in these districts of the early ducks and geese. 
Fall migration. The trumpeter begins to move south early in Sep- 
tember, crosses into the United States the last of that month, and 
reaches the Gulf of Mexico in Texas about the middle of November. 
The last remain on the breeding grounds until October, when the v are 
foreed away by the gathering ice. 
