(Last Updated December 2005)

In 2003, MRC began conducting directed surveys to identify the distribution of three amphibian species: tailed frogs (Ascaphus truei), red-legged frogs (Rana aurora sp.), and southern torrent salamanders (Rhyacotriton variegatus). The distribution of these three species was previously unknown and MRC has accumulated the most robust set of data on these species in Mendocino County.

Tailed Frogs (Ascaphus truei)

Larval tailed frog

To establish the distribution of tailed frogs, 10 surveys were conducted within each of the CalWater planning watersheds selected for sampling. MRC intends to sample all of the CalWater planning watersheds within their forestlands to determine the distribution of tailed frogs by year 2008. To date, approximately 113,811 acres have been surveyed for the presence of tailed frogs (roughly 50% of the acreage owned).

Tailed frog metamhorph

Thus far, 231 surveys have been conducted and 59 surveys detected tailed frogs (~26% of the surveys yielded detections). We have sampled 23 CalWater planning watersheds, of which 10 contained at least one site with tailed frogs present (~43% of planning watersheds yielded detections).

Red-Legged Frogs (Rana aurora aurora and Rana aurora draytonii)

To establish the distribution of both Northern red-legged frogs (Rana aurora aurora) and California red-legged frogs (Rana aurora draytonii), MRC identified the majority of the potential breeding habitat available to the species within each CalWater planning watershed sampled. After identifying the potential habitat ("lentic" habitats with stillwater such as ponds, marshes, and bogs), surveys were then conducted within all of the potential habitats identified.

Surveys were conducted during daylight hours and at night if necessary. The intent of these surveys was to determine if the habitat was being used by red-legged frogs for reproduction. Surveys were focused upon detecting evidence of reproduction, such as the presence of egg masses or larvae (tadpoles).

To date, approximately 119,363 acres have been surveyed (roughly 50% of the acreage owned). There have been 27 CalWater planning watersheds sampled, of which 7 contained at least one site with red-legged frogs present (~26% of planning watersheds yielded detections). There were 87 potential breeding habitats identified, and 20 were being utilized by red-legged frogs for reproduction.

Southern Torrent Salamanders (Rhyacotriton variegatus)

To establish the distribution of southern torrent salamanders, 10 surveys were conducted within each of the CalWater planning watersheds selected for sampling. MRC intends on sampling most of the CalWater planning watersheds within their forestlands to determine the distribution of southern torrent salamanders. To date, approximately 66,439 acres have been surveyed for the presence of southern torrent salamanders (roughly 30% of the acreage owned).

There have been 140 surveys conducted and 20 surveys detected southern torrent salamanders (~14% of the surveys yielded detections). There have been 14 CalWater planning watersheds sampled, of which 7 contained at least one site with southern torrent salamanders present (50% of planning watersheds yielded detections).