Banding Birds: How We Band and How to Report Bands

We are sometimes asked why we band birds. Banding birds provides an invaluable way to study their life histories and chart changes in bird populations, including changes in range, population numbers, and migratory behaviors. Bands do not hurt birds or impact their individual or reproductive success.

There are a number of different ways to band or mark birds. We use two leg bands on peregrine falcons: an aluminum leg band on the right leg and a color band on the left leg. The band on the right leg has a long number with a unique federal identifier assigned by the North American Bird Banding Lab. The color band is an auxiliary marker distributed regionally by the Midwest Peregrine Society to peregrine banders in Minnesota, Wisconsin, Iowa, Illinois, Michigan, Kentucky, Ohio, Nebraska, and Missouri. 

Why two bands?

All banded birds in the United States have to be banded with a federal band. When bird banding protocols were established in 1920, we didn’t have 10×42 binoculars, field cameras with zoom lenses, easy-to-deploy 80x scopes, or other tools of the birding trade. Most birds enrolled in banding studies were economically important species like ducks and geese and almost all band returns came from hunters. Federal bands needed to be sturdy, but they didn’t need to be read from a distance.

The passage of the Endangered Species Act and the availability of spotting scopes and high-powered binoculars changed everything. The architects of the peregrine’s return needed a way to study the new population that wasn’t based on band returns from dead birds. They hit on an auxiliary band that had larger characters etched in a different color than the band, making it easier to read from a distance. Since all banded birds are required to wear a federal band, our birds sport two bands: one federal marker that can be provided to the bird banding lab for identification from anywhere on earth, and one auxiliary band or color marker that we can look up in the Midwest Peregrine Society‘s online database. 

Falcon 96/B, from the Dairyland Power Alma plant in Alma, WI. Photo by Roy Brown Photography.

Falcon 96/B, from the Dairyland Power Alma plant in Alma, WI. Photo by Roy Brown Photography.

Our banding season kicks off when peregrine falcons begin returning to their territories in February and March. We watch cameras and conduct multiple surveys along the Upper Mississippi River to find eyries, determine the onset of full incubation, and plan our banding schedule. We do our best to band nestling peregrines at 21 days of age: old enough to sex and young enough to hand capture and handle well. Have you heard that parent birds will abandon baby birds if a human touches them? While you should leave baby birds alone in most circumstances (great guide here!), parents do not abandon young because humans have handled them. Once we return young falcons to the nest, their parents come back quickly.

Banding tools for nestling peregrine falcons

Banding tools for nestling peregrine falcons

One of us usually holds a bird while someone else bands it, taking great care to avoid hurting the emerging primaries and tail feathers. Both bands are fitted around the bird’s legs before they are closed. The aluminum band is closed with a pliers and the multi-color band with a pop-rivet gun: a technique developed by Charles (Chuck) Sindelar, who was instrumental in bald eagle recovery in Wisconsin. Since female birds of prey are larger than male birds of prey, females take bigger bands. We sex peregrines by tarsus thickness, foot size, and pitch (larger female birds usually have a lower pitch). Although male bands are smaller than female bands, we discovered that females banded as males aren’t damaged when we trapped Husker, a 1998 fledge from the Woodman Tower in Nebraska. Husker, a female banded as a male, fledged 19 young between 2001 and 2007. Her slightly tighter bands didn’t affect her legs or her ability to care and provide for her young.

The color bands we use on peregrine falcons are read with the number on the black part of the band first, followed by the number on the colored part of the band. 96/B, the number on the bird pictured above, makes three appearances in the Midwest Peregrine Falcon database: black/green 96/B, banded in black/red 96/B, banded in 2004; black/green 96/B, banded in 2012; and black/blue 96/B, banded in 2018. Thanks to the color/number combination, we can positively identify this bird as Uncle Bob, banded in 2012 at the Dairyland Alma power plant by me, Amy Ries.

Why do peregrine color bands come in multiple colors? Each color has a run of around 3000 bands identified with a unique number: say,  96/B. Midwestern researchers are currently banding 300-400+ falcons per year. At 400 falcons per year, it would take 7.5 years to go through a complete set of bands. Since falcons have been recorded living as long as 19 years in the wild, we need to make sure a color/number combination can’t come up the same on two falcons. It will currently take us around 21 years to rotate 96/B back to black/green – longer than the lifespan of the oldest falcon known to us. 

When we band peregrines, we record the federal band number, the color band number, the bird’s sex, the actual or approximate age of the bird, the site name, the site coordinates, the bird bander, and other notes, including parent bands, overall bird health, presence or absence of ectoparasites, and treatments given (such as Spartrix for Frounce. We report this information to the Bird Banding Lab and the Midwest Peregrine Falcon Society.

Banding birds provides an invaluable source of information, since the bird’s life history can be looked up and shared with others. Our peregrines have been spotted in Cancun, Mexico, on oil rigs in the Gulf of Mexico, in the Eastern United States (traveling cross-country from the Midwest), in Nebraska (traveling cross-country from Rochester, New York), in Florida, in Canada, and in many locations in Minnesota, Iowa, and Wisconsin. You can report bands to the Bird Banding Lab by calling 1-800-327-2263 or going to their website at If you have retrieved bands from a dead bird, you may keep them. They will want to know:

  • Type of band (federal only, federal plus auxiliary, auxiliary only)
  • How you obtained the band (saw it, photographed it, found dead bird, etc.)
  • The date you saw the band
  • Band or marker info, including band numbers and colors.
  • The bird’s location

If the Bird Banding Lab has information on the bird, you’ll be emailed a cool certificate that provides information about your bird. The bird bander will also be notified. We love notifications!

Certificate of Appreciation

Certificate of Appreciation

We’ve banded Peregrines on power plant catwalks and in elevators, on rooftops, on the ground, and hanging from ropes. We’ve banded on calm sunny days and in howling near-gale force winds, racing down smokestacks and up cliffs just ahead of thunderstorms. Most thrillingly, we have witnessed ‘banding season’ go from one afternoon, when the Peregrine falcon was so highly endangered that only a handful were nesting in the midwest, to a month-long mad scramble to fit everyone in. Thanks to the efforts of bird banders, the return of the Peregrine falcon in the United States is perhaps the most documented population phenomena in natural history. We know the lineage, natal nests, life histories, and genetic make-up of the majority of Peregrines nesting in the United States today.

Watch this video for a look at Peregrine banding at the Dubuque County Courthouse in Dubuque, Iowa.