Southeast South Dakota bird-watchers have a fairly rare specimen to look for this winter. A pair of snowy owls have been spotted near Gavins Point Dam west of Yankton. U-S-D biology professor Dave Swanson says it’s a bit more common to witness snowy owls in Northern South Dakota.
“But every once in a while, they come down this far. And snowy owls are what we call an eruptive species—which means that they’ll move pretty far south in some winters, and you’ll see quite a few of them; and then in other winters you won’t see any of them. And those eruptions are tied to the cycle of lemmings up in the Arctic, where they breed.”
Swanson says the snowy owls’ trip south could stem from a search for food.
Swanson says, “There’s some argument about how this actually works, but I think the latest is, when there’s big lemming populations, the snowy owls have great reproductive success; and a lot of those times, in the winter, when there’s a lot of young ones, the young ones will move pretty far south, and you’ll see quite a few of them. So I think this year might be one of those years.”
Swanson says lemmings make up most of the snowy owls’ diet—but he says they’ll snack on mice and voles as well. Swanson says if the birds stay, they’ll likely inhabit the area through the winter and then go back to the Arctic in spring.
