Did you know, National Band & Tag manufacturers bands ranging in size from hummingbirds to swans? With so many band sizes to choose from, it may be confusing what size you need.

There are two different options for finding out which size leg band you should order:

Option 1: Find the diameter of your bird’s leg. The easiest way to do this is to use a piece of string. You might want to have one person hold the bird, while another holds the string and measures.

  • Step 1: Place the tip of a string onto the bird’s leg and hold it in place. Wrap the string around the leg until the string reaches the tip on the end of the string you are holding in place.
  • Step 2: Mark the point where the string touches the tip with a marker.
  • Step 3: Stretch the string out across the length of the ruler and then locate the mark on the string. Read the measurement on the ruler. This tells you the circumference of the bird’s leg. For this example, let us say the measurement is 34.54 mm.
  • Step 4: Divide your circumference measurement by 3.14. Given the example of a 34.54 circumference, the diameter of the leg is 11 mm. You can then take this diameter to our bird band page, and see that our Size 14 is 11.13 mm, and would be the best size for your bird.

Option 2: Check for your species of bird on the USGS’s Recommended Band Size chart. This is a guideline, and NB&T is not responsible for incorrect size bands being ordered. While the USGS’s list is reliable for most standard birds, your bird could be slightly different. For example, wild mallards usually wear a size 14 band, but farm-raised mallards tend to be a little fatter and may need to go up to a size 16 band.

Next Steps:

Now that you know the diameter of your bird’s leg, you can check out all our bird bands and find the band size that matches your bird’s leg. Don’t forget that each size band needs it’s matching applicator to properly seal it. If you are ordering multiple sizes of bands, you will also need multiple applicators.