Photo Essay: Banding Hummingbirds by Sheri Williamson & Tom Wood
Most of what we know about the lives and travels of hummingbirds comes from hands-on research. As with other birds, banding (a.k.a. ringing) is the most important tool for understanding hummingbird populations, longevity, reproduction, and migration. In the U.S., banding of wild birds is conducted under the authority of the Bird Banding Laboratory (BBL), a federal agency. The BBL issues permits and bands and manages the data collected on millions of banded birds, from Calliope Hummingbirds to California Condors.
The Southeastern Arizona Bird Observatory (SABO) has been banding hummingbirds on the San Pedro Riparian National Conservation Area since 1996. To capture these intelligent and suspicious birds, we bait a custom-made trap with a sugar-water feeder. When hummingbirds come to feed, the trapping team trips a switch that drops a soft curtain around both feeder and birds. Incredibly, some birds will escape by ducking out under the falling curtain. The trapping team gently removes captured birds from the trap and places them in soft holding cages (actually repurposed lingerie washing bags) for transport to the banding table a few yards away.
At the table, the bander removes the bird from the bag and checks for a band. If the bird is already wearing one, the number is recorded. The oldest hummingbird in SABO’s study, a female Black-chinned, wore her band for at least nine years. For “new” (unbanded) birds, the species and sex will determine what size band is likely to be the best fit. The bander closes the tiny, uniquely numbered band around the leg using special pliers and checks the fit. The bands arrive from the BBL as thin sheets of flexible aluminum printed with a unique series of numbers and guidelines for cutting. It’s up to the bander to cut strips of bands out of the sheet, smooth the edges, cut each band to the appropriate length for the final diameter, and form it into a tiny ring.
The lengths of bill, wing, and tail provide basic information about the individual and help to confirm the identification. Each bird is also examined for plumage condition, fat (essential fuel for migration), and color and location of pollen (clues to important natural nectar sources). Possible breeding females are given a quick “obstetric exam” to check for the presence of a developing egg, which will be visible through the wall of the abdomen as a pale bulge.
The team’s scribe records each bird’s “vital statistics” on a data sheet while birds in holding cages wait their turn on a carousel made from repurposed music stands.
The bird is then wrapped in a piece of translucent netting and weighed on a spring scale. A lean male Black-chinned Hummingbird weighs just under 3 grams, slightly more than a penny, while the average male Anna’s weighs over 4 grams, a little less than a nickel. During migration, their weight can increase by more than 50% as they store fat to fuel their epic journeys.
Once all the documentation is complete, each bird is offered a drink of sugar water and placed in a waiting hand for release. With luck, it will return many times to tell us more about its life, its species, and the environments we share.
SABO’s hummingbird banding sessions are open to visitors. Banding season is over for this year, but next year’s schedule will be posted on the online calendar of events.