Why do loons have red eyes?

Jeff Wagner joined the WCCO-TV team in November 2016 as a general assignment reporter, and now anchors WCCO's 4 p.m. newscasts.

There's a certain elegance to the common loon. Its black and white plumage carries a gentle sheen of green as though dressed for a formal affair. Subtle colors that allow its piercing red eyes to steal your gaze.

"There are a few theories about it," said Natasha Bartolotta, the science and stewardship manager at the National Loon Center in Crosslake, Minnesota. "One of the things that we think is the most likely is that it is just a part of that breeding condition or that breeding plumage that they're in."

When the common loon visits Minnesota and other northern states at the start of the breeding season, its plumage becomes bold and dark while the redness in its eyes brightens, creating a sharp contrast.

"If they're trying to attract a mate, that could just be part of trying to signal to another loon that they're in their breeding condition, they're ready to find a nest, they're ready to settle down," said Bartolotta.

In the winter, however, their feathers and bill shift to shades of gray, while their eyes dull to a deep reddish brown. Bartolotta said this helps disprove the theory that a loon's red eyes help them better hunt underwater.

"The fact that the color itself is a little muted when they're in a different habitat but they're still able to find food for themselves, that kind of suggests that it's more a part of just their overall signaling to other loons that they're in that breeding mission," she said.

Several other birds dive into water to catch a meal without red eyes. Kingfishers' eyes are black. Hooded mergansers have yellow eyes.

Lastly, loon chicks are born without redness in their eyes. The color develops years later when they're ready to head north and find a mate, aligning with Bartolotta's point about its connection to the breeding season.

While they don't emit laser beams like many Minnesota artists envisioned, the red eyes remain a striking sight for our region to enjoy.

"It's just part of the beauty that we get to see at this time of year," said Bartolotta.

There are five species of loon. All of them grow up to have red eyes.