About Auxiliary Markers

Science Center Objects

Many researchers use other auxiliary (color leg bands, neck collars, radio transmitters, flags and tags) markers along with federal bands to allow them to identify an individual bird at a distance. To use any of these auxiliary markers researchers need to have federal banding permits and additional marking authorization. See examples of common auxiliary markers below.

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Neck Bands or Collars

Collars are cylinders of hard plastic that come in different colors. Collars may have 3 or 4 characters on them. Codes may be vertical, horizontal, or some combination. The letters, numbers, and other symbols may be highly stylized to allow for easier separation of similar characters.

Collar for Swan and Canada Goose

Neck Collar for Swan (left) and Canada Goose (right)   (Public domain.)












Canada Goose with Neck Colar

Canada Goose with a Neck Collar and Federal Band (Courtesy: Anna Ginsberg)




















Colored Leg Bands

Colored leg bands are made of plastic or metal and come in a variety of colors that give unique combinations because of their placement on the bird (above or below the "knee", left or right leg). The exact placement of the bands, colors of bands, and location of the metal band are all important in identifying color banded birds.

Florida Scrub Jay, Aphelocoma coerulescens

Florida Scrub Jay with a Color and Federal Band (Courtesy:Margaret M. Sloane)













Some birds, notably shorebirds, may have flags and color bands mixed together on the same bird. A flag is a leg band with tabs that extend away from the leg. This flag identifies the country of banding for shorebirds under the Pan American Shorebird Program. Colored leg bands can be coordinated internationally between the United States and Canada, or only locally depending on the species. Colored leg flags may also have alpha-numeric codes on them that identify the individual bird.


Sanderling with a Leg Flag 

Sanderling with a Leg Flag and Federal Band (Courtesy: Mary Jo Adams)












American Oystercatcher with color bands

American Oystercatcher with two Color Leg Bands and Federal Band (Courtesy: Jim Bennight)













Aluminum band and one plastic colored leg bands in a Brown Pelican 

Federal Band and one Plastic Color Leg Bands on a Brown Pelican (Courtesy: Holly E. Cox)

















Transmitters and Other Electronic Devices

Electronic devices such as radio and satellite transmitters, data loggers or PIT tags may be attached to a bird by many methods, including gluing to a tail feather on a raptor or a neck collar on a goose, attaching it to the bird with a harness or glue, and even subcutaneous or internal placement. Banders usually appreciate the return of electronic devices as they are usually expensive and can often be reused after replacement of the battery.

Canada Goose Collar and Transmitter

Neck Collar with a Radio Transmitter attached for a Canada Goose (Public domain.)













Radio Transmitter

Radio Transmitter for Small Birds (Public domain.)











Patagial or Wing Markers

Patagial markers are shapes of vinyl (often circles) or cattle ear tags (square with codes) attached over the leading edge (or patagium) of the wing. These markers are very visible both in flight and on perched birds, although part of the marker may be obscured by feathers on a perched bird.


Condor Wing tag

Wing Tag for a Condor (Public domain.)











Rough-legged Hawk, Buteo lagopus

Rough-legged Hawk with Wing Tag (Courtesy: Mario Lam)













Tail Streamers

Tail streamers are pieces of tape that are folded over a tail feather and project out an inch or two from the end of the feather. The color of the marker and the shape of the tip (notched, pointed, squared) are useful information. These markers are often used in projects with migrant birds, and a cohort mark is typically used(all birds from one day get a red streamer on the left side of the tail with a notch in end of the tape, for example). Even though the individual bird can't be identified, the information is still of use to the bander. Tail streamers are used on birds from hawks to sparrows.


Web Tags and Plasticine Bands

Web tags are small markers of metal with a code (often up to seven numbers or letters) identifying the bander on one side and a number indicating the individual bird. Web tags may identify the local area or nest site of the bird, or be part of a study on chick growth and survival. The use of web tags allows individual marking of birds that were too small to band. Because web tags are used on chicks, they are usually used without banding the bird with a federally numbered band. If the bird is later trapped and is large enough for banding, the federal band is added to the bird at that time. Web tags can allow banders to be more precise in their age determinations that might be possible using the bird’s physical appearance alone, as the tag will indicate the exact year hatched. 

North American banders are also using a clay or plasticine-filled band on waterfowl. These clay-filled bands are similar in shape to lock-on bands but the bands are oval and the inside of the band is filled with clay at banding. As the duckling grows, wear removes small amounts of clay until the duck has worn all of the clay out of the band, which results in a duck with a full-size band on a well grown leg. These bands are made with a federal band number on them, although they formerly used codes similar to web tags. These bands are currently being used on several species of ducks in North America.



Banders use dyes to mark birds in an obvious but temporary manner. Dyes are quickly lost through weathering or molt and are rarely obvious for more than a few months. Dye can help to call attention to a bird that is marked with less obvious markers, like colored leg bands or a radio transmitter. Dyes that are used are generally bright, obvious, and non-toxic to the birds.


Applying Dye in a tern

Applying Dye on a Tern Wing (Public domain.)














Nasal Markers

Nasal saddles and disks are used to study local movements and behavior of ducks. These markers are not as highly coordinated as goose collars, and only allow individual identification within the study area. Nasal saddles are fit over the bill and often have codes on them, while nasal disks are small pieces of plastic in various shapes and colors that are attached to opposite sides of the bill.

Nasal marker

Nasal Marker for ducks (Public domain.)












If the band you are trying to report does not look like the examples above, please go to identifying unusual bands.


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