Yosemite Toad (Bufo canorus)

Threats

The Yosemite Toad is declining in both population and range throughout the Sierra Nevada. The species has all but disappeared from over 50% of its historic range in the Sierra Nevada. Its most significant decline has been noted at lower elevations and at the western edge limit of its historical distribution. Many recent scientific studies have concluded that livestock grazing poses a serious threat to the Yosemite toad and has detrimental impacts through trampling, alteration of meadow habitat, changes in stream hydrology, siltation of springs, bacterial increase from livestock fecal matter, and lowered water quality. There is also evidence that chemical toxins and predation by introduced exotic fish have resulted in a decline in the Yosemite toad population. Remaining populations are thought to not be reproducing enough to survive. Vehicular traffic kills, prolonged periods of drought, and disease all claim partial responsibility in the rapid decline of the Yosemite toad and attempts are being made at various zoological institutions throughout the U.S. to successfully breed and reintroduce this species back into its native range.

Habitat

Endemic to the Sierra Nevada the primary habitat of the Yosemite toad consists of ponds used as breeding areas and nearby meadows, often near pine forests, that provide food. Even though they spend most of their time on land, they are never far from a permanent body of water. In their juvenile stage, Yosemite toad tadpoles swim in shallow pools of melted ice water, and in slow moving mountain streams. They live primarily at high elevations, anywhere from 5,000 to 11,000 feet. These grassland amphibians burrow under the soil, crawl beneath rocks and fallen logs and seek shelter in abandoned rodent holes during the night.

Conservation

The Forest Service concluded in the original 2001 Sierra Nevada Framework Plan that the prescriptions and proposals contained therein provided the most effective management approaches for Yosemite toad persistence and recovery through the limitation of chemical toxins, removal of exotic fish, and reduction of livestock grazing in core toad habitat. The2004 revisions to the Framework do not take this low-impact strategy into account and actually ignore the prevailing science that concludes that grazing practices represent a significant threat to the future viability of the Yosemite toad in the Sierra Nevada. The 2004 revisions which serve as the current guidelines for the Forest Service do not provide for specific direction limiting livestock grazing and no changes to grazing policy have been made in Yosemite toad habitat.

Status

In February, 2000, environmental groups submitted formal petitions with the U.S. Fish and Wildlife Service (USFWS) to protect the Yosemite under the Endangered Species Act. In late 2002 the USFWS concluded that it warrants protection under the Endangered Species Act. Unfortunately, the Service noted that budgetary constraints precluded them from listing the toad as threatened or endangered at the time. This decision was followed by more legal action seeking to force the Service from the delay in designating endangered status to the Yosemite toad. As of 2007, this imperiled species is still not listed under the Endangered Species Act and has also lost the proactive conservation measures prescribed in the original Sierra Nevada Framework following the revisions to that plan in 2004. It is currently a Forest Service Sensitive Species and a California State Species of Special Concern.