American Robins always seem to be awake before me when I camp in the field, but not this morning. I rose while it was still pitch dark to begin a four-mile hike into the wilderness area where I’ll gather bird data. This field work is part of PRBO’s Sierra-wide project to help guide National Forest management with results from our bird monitoring research. At the same time, we are gaining insight into the critical links between birds, mountain habitats, and seasonal variations in climate.
|Mill Creek meadow in the Warner Mountains. These irreplaceable meadows provide benefits for wildlife and human communities throughout entire migration corridors and watersheds. Photo © David Bobzien (used with permission)|
The remote area where I’m working today, within the Modoc National Forest, occupies the far northeastern corner of California but represents the edge of the San Francisco Bay-Delta watershed. Water that falls here, on the west slope of the Warner Mountains, eventually flows through the Golden Gate—if it is not first consumed by plants, animals, agriculture, cities, or evaporation.
During my trek through mixed conifer forest before daybreak, Cordilleran Flycatchers are the first to break into the dawn chorus. The robins must be sleeping in. With 30 minutes to sunrise, I reach the wilderness boundary sign and crest the ridge that defines the edge of the Mill Creek watershed at 7,160 feet. The sky is pink, the air crisp, and quaking aspen leaves are just becoming visible on the far side of the willow-studded valley before me.
My first survey runs along the bottom of the valley, through the emerald meadow on this reach of Mill Creek. To cross the creek, I change into sandals and, using hiking poles, manage to get wet only to my knees. It takes less than 30 seconds, but my toes are already numb. The water rushing by here was snow just two miles upstream. Today is July 7, 2011, and within the past two weeks abnormally late storms added to this year’s heavy snowpack throughout the Sierra Nevada.
Once my counts in the meadow begin, I have to write furiously on the data sheet to keep up with the abundance of birds—flycatchers, warblers, woodpeckers, sparrows. Where my morning’s surveys end, 1,000 feet above the icy creek, I hear a Rufous Hummingbird whiz past and catch a glimpse of its ruby-orange throat. This tiny bird is migrating through high-elevation meadows; it brings to mind the threats posed by climate change for organisms that survive near the limits of their available habitat.
During their southbound migration, Rufous Hummingbirds are highly faithful to the same sites every year as they hop-scotch down the Intermountain West from one emerald meadow to the next, back to Mexico. In years when heavy snowpack persists late into the season, they can go downslope to find the food to fuel their migration. But here along the crest of the Warners, there are no “emeralds” upslope to furnish resources in dry years, when the meadows below wither early.
|Rufous Hummingbird. Photo by Tom Grey|
High-elevation meadows are vital for birds and other wildlife and also for people. Because they can store and filter so much water, and can reduce peak flood flows, meadows make downstream water more reliable for farms, communities, and hydropower facilities. These ecological services will become more crucial as snow- and rainfall patterns shift due to climate change. Restoring ecological function to heavily degraded meadows in the Sierra Nevada is one of the best ways to safeguard our water supplies, protect wildlife—and ensure that Rufous Hummingbirds in the future will find the emerald habitats they need, when they need them.
Brent Campos is a Biologist in PRBO’s Sierra Nevada Group.