7 of the World’s Little-Known Fish Migrations

When I step outside my southern Idaho home on a warm March day, the bird migration is difficult to miss. The red-winged blackbirds have shown up in huge flocks. The first ospreys carry sticks to begin building their nests. I may be lucky enough to hear the trilling of sandhill cranes or the nasally honks of a huge flock of snow geese. Birders, backyard nature observers and casual walkers notice and appreciate this spring bird migration. In the nearby rivers and creeks, other migrations are...