TRUMPETER SWAN. 87 



southern Iowa, on the averag-e, March 19; at Heron Lake, Minn., the 

 averag-e date of arrival is April 4, earliest March 21, 1889 (a ver}^ 

 early sprino); other average dates are: Nebraska, March 16; South 

 Dakota, April 2; North Dakota, April 15; Saskatchewan, April 16; 

 British Columbia al)out April 20. All these dates are later than those 

 which mark the arrival in these districts of the earl}^ ducks and geese. 

 Fall 'migration. — The trumpeter begins to move south earh^ 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 they are 

 forced away b}^ the gathering ice. 



