Who’s that bird at Great Spirit Bluff? It’s Zazu 18/U! So far, we’ve seen Zazu, Elaine U/09, H/34 Kandiyohi, and Newman, who finally returned! What took you so long, Newman? The Falcon Bachelor started before you showed up!
We’ve had some questions about bird bands, so let’s dive in! Why do Zazu (a male from Bay State Milling in Winona, MN) and Elaine (a female from South Bend, IN) both have a ‘U’ on their bands? The short answer: the auxiliary bands we use don’t indicate a bird’s sex or natal region, but are doled out based on need. In other words, it’s a coincidence.
The Midwest Peregrine Society maintains a banding database and orders auxiliary bands for everyone banding Peregrine Falcons in the Midwest. Each color run – black/blue, black/red, black/green – includes a lot of bands. They generally use one-character (A-Z), two-number (00-99) combinations where either numbers or letters can come first. For example, Y/99 and 99/Y are both valid combinations in a color run.
Bands and banding tools for nestling peregrine falcons. The top string are 7’s, so generally for female falcons, and the bottom strings are 6’s, so generally for males. But the auxiliary or color band numbers don’t correspond to sex or origin.
I don’t know how many combinations there are in a run because some look-alike letters might be avoided, letters can be presented in different ways, and we have some two number/two letter combinations in the black/blue run (00/AB, for example). That said, there are currently 2,927 black/blue bands recorded in the database and that is not all of the bands in this color run, so whatever the number is, it is high.
K/92 Faber at Castle Rock. His natal nest is about 11 miles north of this location. His band is black/red because that was the color sequence everyone was using at the time he was banded.
Here’s how it works…
Every year, we inventory our bands and I order whatever I think we need from Midwest Peregrine. Every other peregrine bander in our region does the same. So if I need 75 bands, I get a contiguous string – maybe U/00 through U/75, for example. Brad from Indiana might need 45 bands, so he gets U/76 through V/21. Jackie from Midwest Peregrine needs 75 bands, so she gets V/22 through V/79. Greg from Wisconsin Peregrine needs 75 bands, so he gets V/80 through W/55. And so on. Birds banded in Minnesota, Iowa, and Indiana that year will have bands that start with U or V. Birds banded in Wisconsin that year will have bands that start with U, V, or W.
Nestling falcons. These two bands are read as black/blue 09/U and H/31. The number on the black portion of the band is always read first in a color band of this type, regardless of the color.
Large runs and a single point of coordination help assure that we don’t get the same sequence in the same color at the same time. From a management perspective, it makes sense to dole them out as needed, in string order. But from an outside perspective, it might seem confusing that peregrines banded in Minnesota, Iowa, Wisconsin, and Indiana could all have U in their bands. The best way to determine where a peregrine falcon came from? Look it up in the database! https://midwestperegrine.umn.edu/?vw=search.
Federal bands can provide a clue to sex. Most male falcons get size 6 bands, while females get size 7 bands. The last number in the prefix indicates the band size. So Elaine’s federal band is 1947-56716. The last number in the prefix is a 7, which means she’s most likely a female bird, although she could also be a big male. Zazu’s federal band is 1266-07909, which means he’s most likely a male. When we’re not sure what we’re dealing with, the falcon gets a size seven band.
More on banding here: https://www.raptorresource.org/2020/06/10/banding-birds-how-we-band-and-band-reporting/.
Fans of Elaine, I found pictures of her banding for you! https://www.southbendtribune.com/story/news/2023/05/25/peregrine-falcon-chicks-banded-in-south-bend-as-skip-and-elaine/70251419007/.
The Raptor Resource Project