Report a Marked Loon

Please e-mail me if you see a marked loon and wish to know who banded it and where it breeds during the summer. We get crucial information from these reports about migration routes, winter ranges, and patterns of mortality and injury. These data help us learn where loons live during the year and where and when they get into trouble. Since loon populations are projected to decrease in coming decades, we really appreciate your help in collecting this information, which will help us protect the species.

Reports of marked loons can be:

  • sightings that you or someone else recorded in your notes
  • photos or video showing bands on loons’ legs
  • dead or injured loons with color bands
  • some other evidence of color bands on a loon

Regardless of the evidence you have, please send it along to me. I will do my best to identify the banded loon and provide you with all of the information we have about the bird.

If you have encountered a color-banded loon — either found a dead one, or seen a live one — and wish to report it, here is how to proceed.

Dead Loons

Send me the band number. All birds marked by scientists in North America (U.S. and Canada both) should have a metal USGS band on one of their legs with a unique etched banding number on it. The number should be hyphenated, consisting of a “prefix” and “suffix”, like “1018-06410”. I appreciate knowing about dead loons that folks have found. Please note, though, that all banded birds found dead or injured should be reported to the Bird Banding Laboratory in Maryland, which maintains records of all birds banded, coordinates information for all of North America, and shares data promptly with scientists who color-marked the birds and the folks who find the birds in the first place.

Live Loons (seen well or photographed)

Send me photos, video or careful notes. It is useful for researchers to get reports of living individuals, whether on breeding territories, on migration, or on the wintering grounds. Bear in mind that: 1) researchers have uniquely color-banded thousands of common loons in North America, 2) almost all banded loons have four total bands, two on the left leg and two more on the right. So in order to identify the exact loon you have seen, it will be necessary to: 1) know the exact band color pattern and which leg(s) the bands were seen on, or 2) know the band number (see above). Still, I will do the best I can to ID the loon you have photographed or seen.


The photo below shows the colors of leg bands we use in northern Wisconsin and Minnesota. beneath the name (and abbreviation) of each color band. (As noted above, one of the four bands will always be a numbered USGS silver band.)

Photo of all colors and patterns of leg bands placed on common loons in Wisconsin and Minnesota.

As you can see, there are many colors, and most are similar — or can become similar, if faded — to at least one other color we use. (Researchers in other parts of North America use additional colors and patterns of bands.)


In the photo by Linda Grenzer at the top of the page, the flying loon is banded “yellow over mint, silver over red-stripe”. Thus, this loon’s right leg has a yellow band on top (i.e. closer to the body) and a mint band below (i.e. closer to the foot). Its left leg has a silver band on top (which is the USGS numbered band) and a red stripe below it. Since we can ascertain the exact color and position of all four bands, we can ID this bird positively. On the other hand, Linda’s photo below of the male on her lake, shows us only that the left leg is “silver over red stripe”.

LMG_0352 Banded Loon
An adult common loon preening during the breeding season. Its left leg is clearly visible.

To help out in the process of reporting a banded loon, I have a few tips:

  1. Try to photograph both legs.
  2. Even fuzzy photos can sometimes permit us to ID the bands on loons’ legs.
  3. Try to take and send to us multiple photos of the banded legs of a loon, as this can help confirm band colors and relative positions of bands.
  4. Loons, like many animals, tend to hang out in the same places for many hours or days. It can often be helpful to return to a place where you saw a banded loon once, if you wish to try to get better photos or photos of a leg that you initially missed.

Send photos or descriptions to: with “Color-banded loon: [state or province]” in the subject line of the e-mail. (Example: “Color-banded loon: Minnesota”).

I will respond as soon as possible (usually within an hour) to reports of color-banded loons. If I can ID the bird, I will provide you with its age (if known), banding location, and breeding history.

We really do appreciate folks’ efforts to identify and photograph marked loons. I hope you have the patience to obtain good photos of the two bands on each leg of a banded loon you see or maybe get really detailed and precise notes about band colors. I will do what I can to nail the ID and get back to you!