Fall migration is an exciting time for birders and also for bird banders. A number of banding stations are gearing up in anticipation of a flood of regular migrants and who knows what surprises.
The Bird Banding Lab, a federal agency in the U. S. Geological Survey, coordinates banding activities of native North American birds. To band native birds, one must obtain a Banding Permit, possible only after extensive experience in assisting a licensed bander.
Bird banding has provided a major tool for the study of birds. The first banding of birds we know of was done by John James Audubon in eastern Pennsylvania. He tied some aluminum wire to some nesting Eastern Phoebes and found that the birds returned the following year to nest.
Licensed banders contribute to our understanding of bird migration, reproduction and population dynamics. Banding allows the individual identity of birds to be known. In the United States, a bander is issued aluminum rings, each with a unique nine-digit number. Birds are captured, either with special live traps or mist nets that birds do not see and get tangled in. With the bird in hand, a band is opened, placed around a bird’s lower leg and then closed with specially made pliers. Data on age, sex, fat score, wing length, parasite presence and other information are recorded. The bird is then released.
For larger birds like geese or eagles, the band number can often be read directly with a spotting scope so that a bird need not be recaptured to identify it individually. However, the bands for most birds are so small that it is impossible to read the number at any distance. To identify the band number of a small bird like a nuthatch, the bird must be recaptured.
The Bird Banding Lab serves as the central repository for all banding information. A bander submits her or his banding data (band number, species of bird, age and sex of bird, banding location) to the lab. If another bander captures a banded bird or if someone finds a dead bird with a band, a call to the Bird Banding Lab will allow the observer to know when and where the bird was banded. The Bird Banding Lab also notifies the original bander that one of her/his birds was re-encountered.
The millions of banding records and the thousands of recapture records are available to interested parties. I have used banding data on Pine Siskins, Common Redpolls and other finches to examine changes in the southward winter migration as affected by an increase in bird feeding over the past quarter of a century.
Many banders now use color bands in addition to the required aluminum bands that are placed on captured birds. Color banding requires special permission from the Bird Banding Lab to insure that banders in the same area are not duplicating banding combinations. By using unique combination of color bands, one can identify individual birds without having to recapture them and read the number off the aluminum band. I use this technique with Black-capped Chickadees and Red-breasted Nuthatches.
Here are a few of the ornithological discoveries that have been made possible by banding birds. Arctic Terns are known to migrate from pole to pole, twice a year. By following the disappearance of banded birds (presumably because they died), we know that most small songbirds have a 50% chance of dying every year. We know much about where different populations of birds winter. For instance, Palm Warblers do an interesting criss-cross in migration. Populations breeding in the upper Midwest and Prairie Provinces migrate southeast to winter in Florida while our eastern Palm Warblers migrate southwestward to winter along the Gulf Coast.
Occasionally Rock Pigeons are seen with one or more bands. Because pigeons are not native species, one does not need a banding permit to band those birds. So, pigeon fanciers often band their birds with particular color bands so they can be easily identified. These band combinations are not regulated by the Bird Banding Lab so one must consult pigeon fancier clubs to try to track down the owner of a sighted racing or homing pigeon.
[Originally published on September 12, 2010]