Scientists seeking clues about climate change are finding answers in an unexpected source\\u002D\\u002Dthe humble hummingbird.

Once upon a time, Susan Wethington was a computer development engineer for IBM. But then she fell in love with hummingbirds, and nothing was ever the same again.

"Hummingbirds seem to have entered my life and never left," says Wethington. "It became pretty clear there was a hole in bird conservation [knowledge] when it came to hummingbirds ... and I thought it was an opportunity to fill that hole."

Wethington, who went back to school for a doctorate in ecology and evolutionary biology, has now spent more than a decade filling in the holes of what's known about hummingbirds. And she's found they have a lot to say about how the world's forests and climate conditions are changing.

Through the Hummingbird Monitoring Network she helped found and runs from her home in Patagonia, Wethington and other scientists are gathering hummingbird habitat and climate change data all along hummingbirds' migratory route, from Mexico to Alaska.

“Conservation is not looking at just one site, but looking at the viability of species survival" across the species' habitat, says Wethington. “The goal is to have a network of sites that provide us the information we need to identify the population trends of all western hummingbirds.”

Like little flying laboratories, hummingbirds collect data as they migrate. Researchers and volunteers band the hummingbirds and carefully gather that data, noting whether they survive and return to the same places year after year, whether they breed successfully and even how much they weigh.

The stats tell researchers how hummingbird habitat is changing and how well hummingbirds are adapting to that change.

If, for example, changes in climate shift flowers' blooming earlier or later in the year, the hummingbirds' physical condition and willingness to return to certain sites will reflect that shift.

“If the phenology—that is, the timing of life events, like when flowers bloom—is changing, will hummingbirds be able to adapt and modify their timing?" Wethington wants to know. "If not, there’s huge potential for a die-off."

The Hummingbird Monitoring Network now spans 30 sites, from Mexico City to British Columbia. One of the key sites is in Southern Arizona, just off Sonoita Creek.

There and elsewhere along the hummingbirds' route, the Hummingbird Monitoring Network relies heavily on the help of volunteers. HMN citizen scientists dedicate considerable time and effort--one of Wethington's mainstays travels over 70 miles in the pre-dawn dark--to help suss out the secrets of hummingbirds.

Wethington’s other partner in the project is the Arizona state parks system, and that’s where some of her challenges lie. Budget cuts that slashed 75 percent of state parks staff have put the project at a disadvantage.

“It’s limited, quite limited, by the number of staff we have. We had two other sites we were going to be doing this program, one at Boyce Thompson Arboretum and the other at Alamo Lake, and both had to be abandoned because we just don’t have the staff. And this is in jeopardy too,” says Robert Casavant, manager of state parks science and research programs. “Keep in mind we only have three state natural areas, and two of the three are closed at this time. So that’s how dire the situation is for state parks.”

But despite limited resources, Wethington and her band of park staff and volunteers are doing what they can to keep the project alive.

They will stay on as the days cool and the birds fly south. And they’ll be waiting for them again next spring, hoping for the answers they need to keep hummingbirds and their habitat from vanishing.