Earth Notes: Pajarito Plateau Birds

May 29, 2019

The word pajarito means “little bird” in Spanish. That’s how the Pajarito Plateau in northern New Mexico got its name. But new research has found bird populations are crashing there—issuing a warning for the future of the Southwest. 

Western tanager
Credit Los Alamos National Laboratory

After the Cerro Grande Fire burned through in the year 2000, foresters decided to thin trees to reduce wildfire danger. Ecologists at Los Alamos National Laboratory wanted to survey birds in thinned and unthinned areas, to find how they responded to this management technique.

Then something unexpected happened. Almost all the pinyon pines in the study sites died—left vulnerable to bark beetle attacks. Only juniper was left. 

Over the next decade, bird populations on the Pajarito Plateau plummeted by 73 percent, on both thinned and unthinned sites. Eight species disappeared—including the common nighthawk, band-tailed pigeon, hairy woodpecker, and pygmy nuthatch—cutting the region’s diversity almost in half.

The study’s lead author, Jeanne Fair, says the birds and the trees rely on one another. Pinyons provide shelter and food, while birds disperse the seeds of the trees.

Fair says this research raises new questions. Birds that disappeared might be adaptable species, moving upward or northward into different ecosystems. The ones that stayed, like the gray flycatcher, might be so dependent on pinyon trees they don’t have anywhere to go.

Some scientists predict pinyons could vanish from the Southwest by the end of the century, driven out by rising temperatures and long-term drought.

Surveys like this one help us understand which bird species will decline and which will adapt as their habitat transforms.