What is the common saying that geese fly south when the river thaws?

The river (the seventh day of the winter solstice) thawed, and the geese (the eighth day of the winter solstice) flew back from the south. As the saying goes, 79 rivers open and 89 geese come.

"Wild Goose" refers to the bean geese, and the so-called "August 9 Wild Goose" refers to the sight that people saw the bean geese moving from the south to the north in early spring.

The folk song sings: "Eighty-nine geese come from the Qijiu River, ninety-nine plus nineteen, and they are plowing cattle everywhere." "August 9" indicates that spring is coming and the temperature will slowly rise. After the warm spring in bloom, geese will fly back in droves to feed, and migratory birds from the south will step on the peak of "returning" one after another.

There is another saying:

"79 rivers open and 89 Yan comes." The "swallow" here refers to the swallow, of course. But the time for the swallows to return to the north will be a little later than that for the geese, and it should be from late March to early April. Therefore, from the perspective of more accurate solar terms, "August 9 geese come" is more accurate.

"Wild geese come in August", and spring has really come.