What Purpose Does Bird Banding Serve?

Plover With Identification Bands

James Diedrick / Flickr / CC by 2.0

Bird banding, or bird ringing, is essential to effective bird conservation. The banding of millions of birds annually worldwide contributes greatly to the study of birds' habits that can lead to a greater understanding of their needs. With that information, conservation efforts can be better focused to help keep birds safe, healthy, and thriving.

What Is Bird Banding?

Bird banding is the process of attaching a small metal or plastic band or tag around a bird's leg in order to identify individual birds from the band's unique number. Banding has been used for centuries, with the first bands being used on falconry birds or other captive birds so they could be identified and returned if they were stolen or strayed from their owners. Today, millions of wild birds are banded around the world each year.

Types of Bird Bands

There are several different types of bands used on different bird species. Bands can be metal or plastic, and the unique identification number of each band may be etched or engraved onto the band. Some bands are brightly colored so they can be read at a distance without disturbing the birds. More detailed bands may have informational codes that identify where and when the bird was first banded. Some countries and banding organizations use bands that have the address of the relevant conservation organization right on the band.

Bands commonly used on birds include:

  • Butt-End Bands: These bands clamp closed with blunt ends. This is the most common type of band and is suitable for most bird species, including passerines, ducks, and hummingbirds.
  • Lock-On Bands: These bands have small flanges that will be bent over one another when the band is affixed to the bird's leg so it cannot be pried open. This type of band is most commonly used on small and medium-sized birds of prey, such as kestrels or small hawks, that may work to bend or pry a ring off.
  • Rivet Bands: These bands are riveted closed and are impossible to pry open. These strong bands are typically placed on large birds of prey such as eagles, whose powerful bills may remove or destroy less secure bands.

In addition to leg bands, some birds, such as geese or swans, can wear identification collars. Wing clips can also be used on large raptors, such as California condors. Both of these types of identification tags are useful for noting the bands at a distance without disturbing the birds. Collars, for example, are easily visible on swimming, long-necked waterfowl, while large wing clips can be read while birds are in flight as well as perched.

Regardless of the type of band used, they do not hurt the birds. The bands have no sharp edges, and they are carefully sized so they will not be tight enough to cramp or pinch the bird in any way. At the same time, the band is not loose enough to slip off or snag on any twigs or other materials. Bird bands are made from nontoxic materials and are lightweight enough so the birds are largely unaware of wearing them.

How Birds Are Banded

Many types of birds are banded, including migratory songbirds, shorebirds, waterfowl, and birds of prey. Endangered birds are frequently banded, as are any birds in sensitive areas where conservation study is needed.

Birds can be banded in several ways. In some cases, birds are banded after they have been entered into a wildlife rehabilitation facility because of illness or injury. Some birds, particularly birds of prey, may be temporarily captured from a nest in order to be banded. Bird banding stations are often set up during fall migration at migratory hotspots where birds, especially birds just hatched a few weeks or months earlier, may be caught in mist nets.

When a bird is caught, trained volunteers handle it carefully to avoid stressing or injuring the bird. The band is affixed to the proper leg, and depending on the species, the bird may be measured and weighed as well. The wingspan may be noted, and the bird can be examined for any signs of illness or injury, as well as to determine the gender if possible. All this information can be valuable for conservation studies.

What We Learn From Banded Birds

While the process of banding birds is informational as individual birds are studied, the real use of bird banding comes from recovering or recapturing previously banded birds. Hunters and birders may report sightings of banded birds, and roughly five percent of banded birds are eventually caught during another banding session and can be identified by their bands. Correlating the data that was initially gathered on the bird compared to when it is recovered can provide information on:

  • Migration: Tracking banded birds can show migratory flyways and where birds may detour along a migration route, as well as when they migrate.
  • Bird Ranges: If banded birds are captured in two completely different areas, it can help define where their different ranges are, or note if their ranges are shifting. This can be critical for protecting necessary habitats for breeding or wintering birds.
  • Longevity: Recapturing birds can give conservationists an idea of the birds' ages based on when they were first banded. This can show how populations are being sustained in different areas, and can offer clues about different species' survival rates.
  • Behavior: After a bird has been banded, it may be able to be identified by passive observation if that band is read in the field. This can give ornithologists the opportunity to study the bird's behavior when feeding, mating, nesting, or engaging in other activities.

Bird banding is a non-invasive, long-term method of observing and studying birds without interfering with their natural behavior. This practice provides conservationists and ornithologists with vital information to protect critical bird habitats and pass other conservation measures so birding will always be available to enjoy.