This IBA begins at the northernmost boundary of the Stanislaus National Forest and ends at the southernmost boundary of the Sequoia National Forest in California’s Sierra Nevada mountains. It encompasses Yosemite and Sequoia-Kings Canyon National Parks, the Giant Sequoia National Monument, the Devil’s Postpile National Monument and the Sequoia, Sierra, Stanislaus and Inyo National Forests. Its higher elevation areas are composed of the Ansel Adams Wilderness, the Hoover Wilderness, the John Muir Wilderness, the Dinkey Lakes Wilderness, the Kaiser Wilderness, the Golden Trout Wilderness, and the Domeland Wilderness. Its major watersheds include the Tuolumne River, the Merced River, the San Joaquin River, the Kings River, the Kern River, the upper portions of the Owens River watershed and all of their tributaries.
Approximately, 168 bird species breed during summer in the Sierra Nevada, and more than 300 bird species are known to occur within the region, many of these species are also present in winter, during northbound or southbound migration. At least 80 birds in the Sierra Nevada are known to have their habitat threatened and therefore have a special ranking according to the California Department of Fish and Wildlife. Because the bird species inhabiting and migrating through the Sierra Nevada is so extensive, we will focus here on the bird species most immediately threatened by climate change and existing forest management actions.
The Great Gray Owl (Strix nebulosa): Yosemite is the last sanctuary for almost all of California's great gray owls. Researchers estimate there are only about 200 to 300 individuals in California, and about 65% of the state's population resides in Yosemite. Great gray owls nest in the middle elevations of the park where forests and meadows meet. The owls stand as tall as 2 feet with a 5-foot wingspan and have distinctive piercing yellow eyes accented by large facial disks. Great gray owls, restricted to montane meadows, are threatened from mounting resource use. Threats outside the park include timber harvest, grazing, and development pressures. Nearly intact ecosystems are critically important to support species and to study changes in species, and the national parks and wilderness areas currently provide the most intact ecosystems for the owl, extending protection outside the parks might help increase the birds range of habitat
The Willow Flycatcher (Empidonax trailii): Once considered common throughout much of the Sierra Nevada, the Willow Flycatcher has declined precipitously since the middle of the 20th century. By the late 1990s, the region’s population was estimated at just 300-400 individuals, which is at the threshold for genetic viability. Willow Flycatchers appear to have stopped breeding at many historically occupied meadows. Recent studies suggest one explanation of the decline is poor nesting success, largely due to meadow desiccation, which allows mammalian predators easier access to Willow Flycatcher nests. Meadow desiccation can occur for a number of reasons: roads, logging, grazing, water diversions, to name a few, and these elements are present on publicly managed land and on privately managed land.
The Black-Backed Woodpecker (Picoides arcticus): This avian fire-specialist favors northern coniferous forests of North America. It thrives in areas that have recently burned, and its diet consists mainly of insects such as woodboring beetles and bark beetles, which colonize readily in early post-fire habitats. For nesting, non-migratory black-backed woodpeckers rely upon sound, hard, large diameter snags (dead standing trees), which are largely limited in intensely managed forests. Their populations are dangerously small, with local populations not at a size likely to be sustainable without substantial protections. Commercial logging and post-fire salvage logging in National Forests of the Southern Sierra Nevada continue to threaten this bird population.
The Northern Goshawk (Accipiter gentilis): This is a powerful predator of northern and mountain woods. Goshawks hunt inside the forest or along its edge; they take their prey in short dramatic bursts of fast flight, often twisting among branches and crashing through thickets in the intensity of pursuit. The Goshawk lives in coniferous and mixed forests, and is generally restricted to wooded areas, but may be found in relatively open woods or along edges. It breeds more often in mixed woods than in pure stands of coniferous trees, making the unprotected lower woodlands of the Sierra Nevada especially important. The bird has an expansive range, but it is threatened by logging, fires, and habitat removal across the west.
The California Spotted Owl (Strix occidentalis occidentalis): California spotted owls generally inhabit old growth forests that contain structural characteristics necessary for nesting, roosting, and foraging. Nests are typically found in areas of high canopy cover, with a multi-layered canopy, old decadent trees, a high number of large trees, and coarse downed woody debris. About 75 percent of known California spotted owl locations are on public lands (National Forests), with the remaining on private timberlands. Nests in the Sierra Nevada are most often cavities, but spotted owls can also use broken top trees or platform nests. Spotted owls do not typically nest every year, and nesting is highly dependent on weather conditions prior to and during the breeding season. The owl is continuously distributed throughout the forests of the western Sierra Nevada mountains. In 2015, the owl was petitioned for listing and it still is currently under review. USFWS was supposed to list the animal in 2019, but it has not done so, at the time of this writing.
Conservation priorities should focus on preserving existing habitat by preventing the logging of old growth trees and stopping USFS logging practices, which include road building, pesticide use, bulldozer excavation work and removal brush and understory native plant species, which support prey pollutions for bird. National forests comprise the majority of unprotected public land ownership in the southern Sierra Nevada. USFS policies can change via congressional action, public pressure, lawsuits or the forest planning process. In light of climate change and the ensuing recent fires in 2020, it is vitally important that post-fire salvage logging is halted, as a management activity. Post-fire salvage logging is damaging to habitat, prevents forest recovery, increases the likelihood of fires and threatens the habitat of the black-backed woodpecker, as well as many other bird species. USFS management should prioritize the recovery of forest woodlands and understory brush; this implies closing and remediating roads, which disrupt habitat, increase the likelihood of human-caused wildfires (84 percent), and create management problems, which lead to the spread of illegal marijuana grow sites and the associated rodenticide poisoning. Climate change is exacerbating all of these issues, as the forest is more vulnerable to fire and logged forests are weakened ecosystems that may not be able to withstand dramatic climate changes (drought, insect infestation, increasing fires).
Much of the land is managed by the U.S. Forest Service, (Sequoia, Sierra, Stanislaus and Inyo National Forests), and these areas are of great environmental concern, as they are ones most vulnerable to logging. Private land is interspersed with public land throughout the Sierra Nevada, and development in the foothills affects the availability of habitat. The Southern Sierra Nevada is also home to Sequoia-Kings Canyon and Yosemite National Parks, which are 95-97 percent wilderness areas and include vast interconnected forests; these areas have a very high levels of protection and offer islands of bird habitat, which should be bolstered by added protections throughout the ecosystem, particularly in National Forests.