Report a Marked Loon

Researchers from several different organizations have marked common loons with colored leg bands — mostly during breeding, but also in winter. Banding efforts span North America, from Alaska to Florida, including several Canadian provinces. Color-marking has been particularly intensive in the Upper Midwest (especially Wisconsin and Minnesota) and New England and includes marking of adults and also chicks that have reached four weeks of age. Color-marking and resighting of loons allows us to monitor breeding individuals, calculate annual return rates to territories, and determine stability of breeding populations using statistical models. Marking and resighting efforts are thus an essential tool for loon conservation.

If you have found a dead loon with colored leg bands — or seen a live one — then you can contribute to the loon conservation effort. Many such sightings by the public provide valuable information about loons that have not been seen recently by researchers. These individuals might be adults evicted from their territories or chicks that have reached adulthood and are either seeking to settle or have settled on a breeding territory. In either case, a careful, well-documented report that allows a researcher to identify the individual precisely is likely to be of great value.

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

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”. Dead loons (or any dead banded bird, for that matter) 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.

Live Loons (seen very well or photographed)

It is useful for researchers to get reports of living individuals, whether on breeding territories, on migration, or on the wintering grounds. However, the value of the report depends upon the quality of the sighting. 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, and thus, 3) it is necessary to know the exact band color pattern and location on the leg of each of 4 bands in order to distinguish a given loon from all others whose combinations of bands are similar. The photo below shows the colors of leg bands we use in northern Wisconsin 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, including some old, faded, or stained ones.

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”. As crisp a photo as this is,

LMG_0352 Banded Loon

it would not be enough for us to ID this individual, because only one leg is visible.

To help out in the process of reporting a banded loon, I have developed four rules:

Four Rules for Reporting Photos of Banded Loons

  1. Make sure to photograph both legs.
  2. Try to get crisp, high quality photos in good light.
  3. Try to get photos of bands out of water, instead of under water, because water distorts colors and patterns.
  4. 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.

Send photos 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 a day) 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. (Sometimes it can be rewarding to get a thorough profile of the loon you have photographed!)

Sorry to be so demanding about photos of loons 🙁 . We really do appreciate folks’ efforts to identify and photograph marked birds. But we also need to be clear about the kind of information that allows us to positively identify a loon. I hope you have the patience to obtain sharp photos of the two bands on each leg of any banded loon you see — or know a good photographer who owes you a favor and can photograph the loon’s legs for you! If so, thanks so much for your efforts. We, and the loons, appreciate them!