Probing a hummingbird mystery — one band at a time

Ruby-throated Hummingbird

The tiny captive is a Ruby-throated Hummingbird, held firmly in fingers that are far bigger than he is. What happens next will help solve an intriguing migration mystery affecting one of the world’s most intriguing birds.

Along the North Carolina coast, hummingbirds are creating a birders’ kerfuffle by staying into the winter when they’re expected to be headed to South American with millions of their fellow migrants. Susan Campbell, an ornithologist from Southern Pines, and the state’s leading expert on hummingbirds, is trying to figure out why.

First, Campbell tags the hummingbird with a small aluminum band on his leg, then weighs and measures him and puts a dollop of white paint on his forehead. After a sip of nectar, this young male is ready to be set free in the woods near North Carolina’s Hatteras Island to join the research project.

Susan Campbell

“This is one of the last frontiers in bird research right now,’’ Campbell said. Over the past 20 years, she has banded some 4,000 hummingbirds in North Carolina in hopes of tracking their travels to try to make sense of these migratory patterns.

The banding last month was part of a demonstration to raise visibility of the volunteer campaign to study the 15 species of hummingbirds that migrate through North Carolina. This is one of the best places there is to do it: More hummingbirds have been spotted in North Carolina than anywhere in the U.S. but Arizona.

Here’s a video of the banding process: 


While the state’s hummingbird population is strong, there are contradictory trends going on. Hummingbirds are struggling with their breeding, and the numbers of young are dropping in the Carolinas. The insect population, which along with nectar from flowers and feeders sustain the birds, is decreasing as well.

The birds keep coming to North Carolina, many just passing through on their spring and fall migrations. But for years now, a small segment of hummingbirds, mostly Ruby-throated and a handful of Rufus, are staying into the winter.

It may be that the proximity of the Gulf Stream just offshore keeps the weather warm enough for them, or perhaps the existence of a maritime forest there may be the attraction. In Buxton, where the banding took place just down the street from the famous Hatteras Lighthouse, volunteers have spotted about 20 individual hummingbirds hanging around this month after their peers have headed south.

It’s important because there’s so much change afoot in the avian world with the steady loss of habitat, rising temperatures and shifting food supplies. Researcher need to understand how species are adapting — and in some cases not adapting — to figure out what can be done.

“It’s something that really gets people’s attention,’’ said Campbell. “It’s quite counter-intuitive that these birds are staying here in the wintertime.’’

The birding project takes a basic approach while providing a powerful flow of information. The birds are captured by setting up a feeder inside a small cage. When a bird flies in, somebody pulls a string to close the door, and then the banding process begins.


On the day of the recent demonstration, Campbell caught two Ruby-throated Hummingbirds. Their bands have a unique number in a database used to track the comings and goings of the hummingbirds if they’re captured again.

Campbell scoops up a hummingbird in the trap.

Campbell says the banding has helped document where and what kinds of hummingbirds are visiting and breeding in North Carolina. Researchers have also learned that the birds are often getting in two rounds of breeding a year, which is an important development when production is down.

The banding project is funded entirely by contributions to the nonprofit Friends of North Carolina State Museum of Natural Science. The humble nature of the project is an example of how tough it is to carry out and pay for important research, said Campbell.

While North Carolina’s hummingbirds don’t get much attention from wildlife agencies, they are able to draw a steady flow of support from all sorts of fans. Hummingbirds have always been been fascinating due to their minuscule size, (average weight is about 3 grams), iridescent plumage and acrobatic flight. 

A female Ruby-throated hovers near the trap used for banding.

“We just have so many people that are paying attention. I think we’ve got a lot of people across the state that are really keeping an eye out for these birds,” Campbell said. “Hummingbirds are very special to people. They are so unique.”








OUR NEW BOOK: “A Wing and a Prayer”

Can We Save Our Vanishing Birds?

A riveting journey through the research breakthroughs, risky experiments and promising campaigns to save birds across the hemisphere, the book is praised from The New York Times’ book review to Good Morning America.


One response to “Probing a hummingbird mystery — one band at a time”

  1. Fascinating story. Thanks, Anders!

Leave a Reply