The group's data from the peak of migration (for Anna's, Black-chinned, and Rufous hummingbirds) will be pooled with that of similar HMN groups working across the southeastern Arizona sky island region, California, Utah, Idaho, New Mexico, Colorado, British Columbia and Mexico City.
With the collected HMN data combined with remote sensing and other biological data, Wethington will work with a team of scientists led by ecologist Catherine Graham of Stony Brook University to study how the hummingbirds might adapt to the changing climate. A NASA grant supports the research as part of the agency's project to investigate how wildlife and ecosystems will respond to climate change.
With the Earth's rapidly changing climate, Wethington fears hummingbirds will face ever-greater challenges. In June, for example, biologists David Inouye and Amy McKinney of the University of Maryland and their colleagues reported in Ecology that glacier lilies were blooming earlier in the spring, at a time out of sync with the arrival of Broad-tailed hummingbirds traveling north.
"One of our biggest concerns is the changing phenology of the flowers that they visit to the timing of their arrival," Wethington says. Broad-tailed hummingbirds are expected to be among the most heavily affected species because they require high-mountain forest breeding sites to nest and raise their young.
So far, the Broad-tailed hummingbirds have proved resilient. Consider what they went through in the winter of 2010 to 2011, when freezing temperatures stretched as far south as Jalisco, Mexico. The following spring HMN researchers recorded a greater number of Broad-taileds at low- and mid-level elevations during migration. They noticed that the birds that made it through the cold survived by delaying their molting and changing the location of their stopover sites to lower elevations.
"The fact that they can do that is interesting," Wethington says.
Also interesting, she adds, is the role of fire as a land-management tool. Wildfire can be tragic to hummingbirds, as it is for any other species, but it can also help open up an area, return organic material to the soil, and stimulate the production of flowers—as it has this year—leading to rebounding populations.
Future projects are planned to help foresee how hummingbirds adapt to extreme weather patterns and to help inform conservation efforts, such as habitat restoration and enhancement, as well as public land management.
Wethington encourages more people to become involved. "It's a huge commitment. We wouldn't have ever gotten started without volunteers and citizen scientists."