SHOREBIRD LEG FLAGS; how to make the perfect leg flag.

SHOREBIRD LEG FLAGS; how to make the perfect leg flag.

The North American Banding Council has designated that as scientists capture and tag birds, we do so in a structured way so that everyone can access one database and determine who, what, where, and when that individual bird was tagged. Banding and recapturing is how we first made strides in determining where migratory birds went after they left the breeding grounds or migratory stopover locations when they were headed…well, somewhere. It’s also how we have been able to determine proximate ages for individual birds and for species. How long does a little bird live? Believe it or not, some small songbirds can live over 10 years! And likely that is a conservative number. All that has been possible due to banding efforts where we capture birds, place uniquely coded bands on each one and record all the information about where it was banded, the species, other measurements etc.

Sanderling. Photo by: Nick Docken

Sanderling. Photo by: Nick Docken

In many cases, birds are mostly resighted and not recaptured, meaning that someone was looking through their binoculars and noticed a bird has some kind of marking on it. It’s wonderful, especially if the bird has a marking that is unique to THAT bird. Smaller birds can be given leg flags that have unique colour and code on them to help us identify from afar who they are and where they were tagged. These leg flags are colour coded by country which is even more fun, especially when you are in the Canadian Arctic and you see a red knot with an orange flag….Hello Argentina!!!! That bird has come a long way to breed.

Photo by: Nick Docken

Photo by: Nick Docken

It is however not a right but a privilege to handle birds. Each person is registered and has applied for a permit to capture and handle birds only after weeks to months of mentorship from experienced banders at permitted banding stations in the country. Code of ethics, safety, banding regulations all need to be followed precisely. “The bird comes first” before anything, so it’s safety and proper handling is our number one priority. With this responsibility comes not only the proper care and handling but the proper administering of any item being placed on the bird, such as the bands, flags or markings.

Making the perfect leg flag for smaller birds (band size 1A, 1B, 3 etc)

Things you need:

  1. Darvic plastic or the new Salbex plastic products 1-2 mm thickness cut into strips 1cm x 10 cm

2. Small but hardy clamp that can tolerate some heat

3. An assortment of nails that fit the measured diameter for the bands designated for your target species




Sourced from:

4. Heat gun


Take your flat pre-cut Darvic plastic piece and press around the nail sized to your leg band requirement. Then pinch in place as close to the nail as possible:

Hang your heat gun (I used Mastercraft’s model), and turn the heat setting on low. Place one side of the band with the curved side facing out under the heat for 5 seconds. You will see the plastic mold nicely to the shape of the nail. Then turn and heat the other side for 3-5 seconds until shaped. *Do not heat for too long, after the plastic gets too soft, it will droop and will not return to the right shape, aka the flag is garbage.

Let cool for 5 seconds and remove from clap. If the opening is not flush and forms a V shape this is a no no.

Flip the flag in the claps so the tail end is sticking out and give it a 3 second blast of heat, then pinch with your fingers being careful to not burn yourself. Don’t press too hard or the plastic may bend.

And Voila, the perfect leg band. Now trim and they are safe for use.