|Photography by Don Carroll|
When you watch hummingbirds at a nectar feeder, it might appear as though these tiny birds are using their long bills as a straw. But the mechanism is very different.
Hummingbirds trap nectar from flowers and feeders on a microscopic membrane located along their split tongues. Loaded with nectar, their long tongues move in out of their bills about 15 times a second.
Don Carroll first noticed the long, bifurcated tongue of a mother hummingbird while filming her feeding babies in the nest she had built on a clothesline on their patio in Las Vegas.
“Most people don’t realize how long their tongues really are,” Carroll said. “In North America, hummingbirds’ tongues come out double the length of the bill. Those in South America are even longer in order to reach into large trumpet flowers.”
He started shooting still images of the tongue. “But because it moves in and out of the bill so fast, it was always a blur,” he said.
So he and his wife, Noriko, embarked on a project to capture detailed images of this action using a slow-motion video camera.
“We didn’t want to shoot in a lab or a cage, we wanted to shoot in the wild. No one has ever done this, so I had to learn on the fly,” he said.
In 50 years of professional photography, this was his most challenging project, Carroll said. The high-magnification and extremely fast shutter speeds required extra lighting. So he devised reflective mirrors around a specially designed glass feeder. The effects of the mirrors added to the brutal summer temperatures that often reached 130 degrees in the sun.
“We had to work with wet towels on our heads,” he said.
The heat also created problems for the birds. The nectar, though placed in the feeder chilled, could heat rapidly to 150 degrees and therefore required constant changing.
“In one segment you can see a hummingbird back away from the feeder and spit out the nectar,” he said. “I suspect it went sour or was way too hot.”
The stars of the show include several Anna’s, Costa’s and black-chinned hummingbirds. More females than males took to the spotlight.
“There was one female Anna’s that seemed fearless and came more often than the others,” Carroll said. “The hummingbirds in the our yard were already used to us because we’ve had feeders for a long time. Generally when the feeders are empty or too hot they will fly up to the window to let us know. They have a way of communicating once they become familiar with you.”
The couple’s video, “Secrets of the Hummingbird Tongue,” was selected from among 600 entries to be featured at the seventh annual New York Imagine Science Film Festival in October and earned the People’s Choice Award for significant home scientific research.
Segments from this video have been added as bonus footage to the Carrolls’ previous work, “First Flight: A Mother Hummingbird’s Story,” which chronicles the hatching of two tiny eggs to the fledgling of the babies. The video is available for $19.99 at local nature stores or online at hummingbirdstory.com.