Figure 17. Weather ideal for avalanche of spring migrants. The map shows wind and air- 

 pressure patterns at 7:30 a.m., April 8, 1954. Few migrants had reached southern Mani- 

 toba by the first week of April. Canada Geese were the only waterfowl in the province, 

 with most ducks and geese still south of Grand Forks, North Dakota. On April 7 north- 

 west winds of 25-35 m.p.h. rushed from the "high" centered in northern Saskatchewan, 

 creating the worst blizzard of the year, with visibility reduced to 20-30 feet in the drifting 

 snow on the Portage Plains. It was calm and clear by nightfall, however, and the morning 

 of the eighth was bright and sunny, with mild southeast winds of 15-20 m.p.h Red-winged 

 and Rusty Blackbirds appeared in numbers by 9 a.m., and through the middle of the day 

 there was a heavy migration of Rough-legged and Red-tailed Hawks, with lesser numbers 

 of Sparrow Hawks. Canada Geese were seen shortly after sunup and their passage through 

 continued all day, one of Delta's biggest goose migrations on record. The first Whistling 

 Swans and a grand movement of Mallards and Pintails arrived between 3:00 and 4:00 p.m., 

 and a few Great Blue Herons passed through before nightfall. South winds and bright, 

 mild weather continued till about noon on the tenth, with White Pelican, Richardson's 

 Goose, Shoveller, Sandhill Crane, Yellow-headed Blackbird, and Song Sparrow adding 

 their numbers to the grand passage. By 3:00 p.m. on the tenth the wind had shifted to 

 west, then northwest, and the migration ended. 



