What are the current threats to wildlife in the Northern Yosemite region?

One of CSERC’s most important tasks is to attend critical hearings, expertly advocating for wildlife and for the habitats that support their needs. Of course, wildlife species can't speak for themselves or write responses to Environmental Impact Reports, Environmental Assessments, or other technical documents. CSERC serves as the voice for local wildlife in issues such as the following:

livestock grazing
Dams and Diversions
Development Projects

Livestock grazing threatens wildlife habitats

Livestock grazing on public lands has a variety of effects on wildlife habitat, depending on how much grazing takes place and the time of the year. Without intensive herding or other active management, cows often trample stream banks, causing erosion and sedimentation that affects amphibians, fish, and other aquatic species.

Over-grazing of meadows can eliminate or degrade grass and wildflower habitat for many wildlife species. Of special concern is the loss of shelter - in the form of tall grasses - that small wildlife species depend on for protection from scorching summer sun or from aggressive predators.

Read more about grazing problems here

Yosemite Toad

Yosemite Toad, a threatened species
photo by Lucas Wilkinson, USFS


Livestock grazing removes vegetative cover ...


that is beneficial to many wildlife species

Chemical treatments effect on wildlife and wild places

Both the U.S. Forest Service and private lumber companies continue to use intensive herbicide treatments to kill off ferns, wildflowers, shrubs, and hardwood trees that might possibly compete with their crops of conifer trees.

Herbicide treatments like these often contaminate water and almost always denude expansive areas, eliminating valuable woodland habitat. Such chemical treatments are meant to boost the growth of conifers, thereby increasing wood production, but the habitat loss can be devastating to forest wildlife. For thousands of years the forests survived and flourished without chemical treatments; although logging companies replant the trees they've cut, the herbicide-treated habitat is nowhere near as inhabitable to wildlife.

CSERC strongly opposes widespread chemical applications in our local forests.


Clear-cut that has been treated with herbicides and converted into a tree plantation

Logging removes habitat for sensitive wildlife

The cutting of large trees and the creation of large openings in the forest often eliminate necessary structural habitat for goshawks, fishers, martens, spotted owls, and other sensitive wildlife species.
Clear cuts denude entire hillsides, removing plants that provide food and shelter. Bulldozed skid trails cause erosion that can lead to sediment washing into streams. Logging slash increases the risk of forest-damaging wildfires.

Intensive logging disturbs wildlife species who need refuge from chainsaws, noise and traffic.

Wildlife can co-exist with logging - but only if snags, downed logs, large trees, hardwoods, and adequate canopy cover are retained at the logging site.

Click here to learn more about issues related to logging


Habitat for the Pacific fisher (left - photo courtesy of Rebecca Green) and spotted owl (right) can be destroyed by some logging practices, such as clearcutting of old growth forests.

Dams and diversions harm river ecosystems

For more than a century, the demand for more water for agriculture and domestic use has led to an increase in dams and diversions. These structures cause streams to dry up, disrupt the river ecosystem, and prevent fish and aquatic biota from accessing more than a small section of river.

New land development threatens to take even more water from local rivers and streams. Fish, frogs, ducks, river otters, kingfishers, ospreys, and many other species would suffer without CSERC's intense involvement in these planning processes, backed by years of experience in local water issues. Rivers and the wildlife that depend upon them are threatened by new dams, diversions, or water management policies that prioritize water use over habitat quality. Even with our vigilance adressing water issues, new demands on water resources will continue to stress local aquatic systems.

Click here to learn more about issues related to the water in the Yosemite region.



Perhaps the single greatest challenge to the Sierra Nevada ecosystem at this time is the pressure to subdivide and develop land throughout the foothills. Presently, there are plans for thousands of new lots across Tuolumne and Calaveras Counties. Along with new subdivisions come the plans for golf courses, new commercial centers, and the many roads that fragment and damage wildlife resources.

CSERC staff review more than 100 development or subdivision proposals each year as we attempt to prevent or alter the worst projects, improve marginal projects, and support appropriate, well-planned growth. The oak woodlands across the foothills are suffering significant degradation, which must be mitigated as the land continues to be developed.

Click here to learn more about issues related to land planning.