As the sun began to set behind the Huachuca Mountains, the evening air filled with the sounds of crickets, toads and little wings flapping thousands of times a minute.
The San Pedro Riparian National Conservation Area plays host to the San Pedro House, home to the longest running hummingbird banding project in the world.
Tom Wood and Sheri Williamson, creators of the Southeastern Arizona Bird Observatory, first began banding hummingbirds at Ramsey Canyon Preserve in 1988, and celebrated the 20th anniversary of the San Pedro Hummingbird Project Oct. 3.
Over the course of 20 years, the duo has banded more than 6,000 different birds by the San Pedro, and have caught over 10,000 in total.
In order to get a banding permit, it generally takes an apprenticeship with a master bander, and in some cases can require banding over 200 birds and showing enough knowledge in handling, identifying and banding them before being deemed fit to do so unsupervised.
The banding process begins when birds are caught in a trap near a feeder, then are transferred over to a bander who checkS the bird’s measurements, sex, fat, and amount of pollen present. The average hummingbird weighs the same amount as an old copper penny, which is just three grams.
When Wood and Williamson first began banding birds at the San Pedro, the environment around them was as much a focus as the birds in their hands. “We realized that hummingbird banding down here was really important,” Wood said.
“People love hummingbirds, so if we can show through our studies that this place is important to hummingbirds, then that makes it important to people and that’s the ulterior motive to our project.”
Williams offered another idea.
“We always like to use the coal miner’s canary analogy,” Williamson said. “Birds are very sensitive environmental indicators, and by looking at the overall health of the birds that we handle – checking them for reproduction, looking at their weight, looking at how much pollen they’re carrying or not carrying from flowers – all of those things are reflections of the environment that sustains them, so they really are our coal miner’s canary, they tell us how the San Pedro river is doing. “
According to The Nature Conservancy, a non-profit group dedicated to protecting ecologically important locations around the world, the San Pedro River plays a vital role in bird migration, providing a migratory corridor that supports nearly half of all bird species found in the United States.
The future of the San Pedro serving as a stop for migratory birds hinges on the health of the ecosystem, which state and federal organizations are doing their best to preserve.
In October 2014, four property owners along the lower San Pedro River teamed up with the U.S. Forest Service, Arizona State Forestry, Arizona Game and Fish Department and The Nature Conservancy to protect 613 acres of land in an attempt to ensure the longevity of the San Pedro as a healthy ecosystem.
Earlier this year, the U.S. Geological Survey released an assessment on the state of San Pedro water resources, and found that the amount of water entering the soil from the San Pedro River has decreased by 44 percent from 1914-2009.
Less water means less growth, and less food source for the birds.
This is one of Tom Wood’s concerns. “This river is so fragile and so imperiled, and to make people care about it, you’ve got to connect it with things they care about.”
Tim Towle is a reporter for the Arizona Sonora News, a service from the School of Journalism within the University of Arizona. Contact him at firstname.lastname@example.org
Click here for a Word version of this story and high-resolution photos