CO0052918 - Laserfiche WebLink

Home Browse Search

Soil Investigations for Data Collection in the Delta Initial Study/Proposed Mitigated Negative Declaration 48 f. If any special-status reptiles or amphibians are observed within the Impact Area, the on-site biologist will determine if the work can continue without harm to the individual(s). If the biologist determines that it is not safe to continue work, all work will cease until the animal has left the Impact Area. Once the individual(s) is determined by the on-site biologist to have left the Impact Area and is out of harm’s way, work may resume. g. Piles of rock, rip-rap, or other materials that could provide refuge to reptiles or amphibians will be avoided. If movement of such materials cannot be avoided, a qualified biologist will survey the area prior to disturbance and monitor the material movement and restoration of the area following completion of Proposed Project activities. California red-legged frog (Rana draytonii) California red-legged frog is listed as Threatened under FESA (USFWS 2019b) and is identified as a California Department of Fish and Wildlife (CDFW) Priority One Species of Special Concern (CDFW 2019b, Thompson et al 2016). It is the largest California native frog, measuring 1.75 to 5.25 inches SVL, with smooth skin and prominent dorsolateral folds. Its coloration can vary from reddish-brown to gray or olive, often with a red lower belly and hindlegs (Nafis 2019). California red-legged frog is endemic to central California, with a range historically extending from southern Mendocino County southward along the interior Coast Ranges to northern Baja California, Mexico, and inland from the vicinity of Redding, Shasta County, California, along Sierra Nevada foothills south to Fresno County at elevations from sea level to approximately 5,000 feet (Nafis 2019, Thompson et al 2016). It is found in a variety of aquatic habitats including permanent and ephemeral ponds, perennial and intermittent streams, seasonal wetlands, springs, seeps, marshes, dune ponds, lagoons, coastal dune drainages, and human-made aquatic features (Thompson et al 2016, Halstead and Kleeman 2017), and has been known to migrate as much as a 1.7 miles into the upland. Upland habitat used includes woodlands, grasslands, and coastal scrub. Breeding occurs from late November through late April, with earlier breeding generally occurring in southern localities. Females lay eggs in clusters up to 10 inches across, attached to vegetation two to six inches below the surface. Eggs hatch in 6-14 days, depending on water temperature (Thompson et al 2016), with tadpoles undergoing metamorphosis in four to seven months, although in some locations they have been known to overwinter (Nafis 2019) completing metamorphosis the following spring. Red-legged frog has a high potential to occur within the Study Area based upon presence of suitable aquatic habitat and upland refugia and proximity to reported