Band of Brothers
How this affects the finches remains widely unknown, but ornithologists can predict how their habitat and food sources might change. “With the rosy-finches, their alpine environment is probably waning,” says Wolf. “On sky islands the temperature is going up, and plants and animals have physiological limitations. They’re being burned out of their environments.” Some studies show that at high-altitude summer breeding grounds, rosy-finches depend on insects that drift on wind currents to higher altitudes until they reach the cold snowfields, where they die. “If you don’t have those snowfields anymore, there may not be these insects,” says Wolf. “That could alter the finches’ food availability. They don’t appear to have the flexibility to go lower, and they need a high protein source. That could alter the whole diagram of rosy-finch breeding productivity and success.” They may be able to move to other mountains, but suitable alpine habitats in the region are few and far between. “There’s not enough data, and in that way this monitoring project is the only game in town,” Chris Witt says of Raymond and Michael’s research.
Raymond and Michael have accumulated multiple years of data, so when global warming’s effects on alpine ecosystems become better known, they can correlate that information with the health of rosy-finches, and even potentially extrapolate that data to other species. A warming alpine ecosystem “may not be an issue today or next year for these particular birds, but eventually it will be,” says Cox, who still bands birds with Raymond and Michael on Sundays.
Ryan could never have realized the extent to which his project could help the birds he cared for so much—or the interplay between his project and global warming. Still, his partners will forever remember his contribution, and they keep some of his traditions alive, like allowing visitors to release birds from the deck after all the relevant data has been recorded. “After five years it’s still so awesome,” says Michael. Recently they even recaptured a brown-capped rosy-finch Ryan had banded in 2004. “There were a lot of happy people,” says Nancy Cox. “A lot of us also shed a few tears.” Knowing Ryan’s bird is alive and well, and enjoying its homecoming, confirms the conclusion that rosy-finches rely on this place for survival—and underscores the importance of saving it.