Bald eagles are migrating back to Minnesota and may be seen in large numbers across parts of the state over the next few weeks, according to the Minnesota Department of Natural Resources (DNR).
Lake Minnetonka is a favorite nesting and fishing spot for bald eagles, and the season's first sightings are expected to start rolling in over the next week or two.
"It's definitely time for folks to keep their eyes out," according to Lisa Gelvin-Innvaer, DNR regional nongame wildlife specialist. "Usually we see these bigger pulses of migrating eagles a little later in March, but it appears that timing may be early for a lot of natural events this year due to the mild winter."
Only two states, Florida and Alaska, have greater nesting populations of bald eagles than Minnesota. In 2005, researchers estimated there to be more than 1,300 active nests in this state.
Fall migration typically occurs as lakes and rivers freeze over, since most eagles prefer a diet of fish. Bald eagle wintering grounds typically contain open water, ample food, limited human disturbance and protective roosting sites.
Gelvin-Innvaer said that not all bald eagles migrate in the fall. In southern Minnesota, it's common for some eagle pairs to stay the winter, especially during milder winters.
"This winter has been a good example," Gelvin-Innvaer said. "We've had more open water than usual, and with the lack of snow, carrion has been easy for eagles to find."
Bald eagles that stay local may begin courting and nesting as early as December or January. Other bald eagles return to their breeding territories in late winter, as soon as a food source is available.
"Eagle migration hotspots are a bit of a moving target, so it's hard to say where the eagles are right now," Gelvin-Innvaer said. "In Minnesota, the biggest migrations tend to be along the Minnesota River corridor, the north shore of Lake Superior and around Lake Pepin in southeastern Minnesota."
Adult bald eagles are easily identified by a white head and tail contrasting with a dark brown body. Bald eagles attain full adult plumage in their fourth or fifth year. In flight, bald eagles are sometimes confused with turkey vultures. However, bald eagles have a tendency to soar on flat, board-like wings, while turkey vultures fly with their wings in a v-shape.
Information provided by the Minnesota Department of Natural Resources.