By Erica LeMoine, LoonWatch Coordinator
Despite the many presentations that I’ve given over the past six years, it always gives me a thrill when I hear the “oohs” and “aahs” of an audience learning something new about loons, reacting in amazement to what our Wisconsin colleagues and researchers have unraveled about the mysteries of loons.
Much of what has been discovered in the last thirty years is the result of researchers being able to identify individual loons by banding them, which is no easy feat. Loons spend most of their time in the water and routinely dive for a minute or more, surfacing hundreds of feet away from the place where they dove. They are also able to hide by compressing their feathers, letting out air, and lying flat on the surface of the water.
It wasn’t until the development of night-time capture techniques in the 1990s that researchers were able to consistently capture and band loons. Since then over three thousand loons in northern Wisconsin received US Fish and Wildlife Service metal bands and color plastic bands. Each loon is fitted with a unique band color combination, allowing scientists to identify an individual loon’s behavior and track its location.
Through updated technology and loon-specific banding techniques, some amazing new facts about juvenile loon’s migration have emerged.
In 2014 and 2015 Kevin Kenow, a researcher at USGS Upper Midwest Environmental Sciences Center, satellite-tagged juvenile loons in Wisconsin and Minnesota. Like adult loons, the juveniles migrated to the Gulf of Mexico, and by the time spring migration was underway, these juveniles migrated like the adults. But just not back to Wisconsin.
Instead, the three satellite-tagged loons who survived their first winter, migrated northward in the spring of 2015 up the Atlantic Coast and summered in the Gulf of St. Lawrence off the coast of Nova Scotia, and then returned for a second winter to the Gulf of Mexico. This behavior is consistent with past band recovery data that indicate some juvenile loons may move northward up the Atlantic Coast during summers.
Even more amazing: another researcher, Walter Piper, has discovered that banded chicks that return as adults disperse close to the lakes where they were born, with male loons returning to within seven miles and female loons returning to within fifteen miles of the lakes where they were born.
And to top that, these juveniles return to the same type of lake where they were raised. If they hatched on a flowage, they’ll return to a flowage. If they hatched on a seepage lake (not the best habitat), they’ll return to a seepage lake. All of that after a three-year absence, many different types of water bodies, and water quality during migration—from the Great Lakes to inland lakes to the Gulf of Mexico.
This leads us to wonder about the imprinting that has to happen within those first twelve weeks of life, as the loon grows from chick to juvenile fledgling. This research leads to even more questions that our researchers are working to answer. I feel privileged to share in the awe and amazement of these regal birds—sentinels of our northern lakes.