FERC Project No. 2079 - PCWA Middle Fork American River Project ...

Application for New License Middle Fork American River Project (FERC Project No. 2079)
substrates, such as sand and silt near main channel pools or around side channel
pools, this association appears to be relatively low compared to coarse substrates. The
canopy in streams that support this species is usually semi-open with riparian
vegetation creating dappled shade, thus providing cool cover during the hottest part of
the day as well as open areas for basking (Van Wagner 1996). Fitch (1938) suggested
that this species may be limited by dense canopy and Moyle (1973) reported that
individuals were not found at sites with> 90 percent canopy.
Although usually found in perennial streams, adults will inhabit isolated pools when
water flow declines in summer (Fitch 1938, cited in Hayes and Jennings 1989). The
movements of juveniles can be quite extensive in summer and late fall, as foraging
individuals into diverse habitats (Van Wagner 1996). Therefore, the stream habitat
used by FYLF throughout their life cycle is complex. Breeding occurs in early spring
near tributary confluences in larger river systems in the Coast Range (Kupferberg 1996)
and in shallow, low velocity areas in small streams in the Sierra Nevada (Van Wagner
1996). Mating occurs from March to July and egg laying occurs from April to July. Egg
masses are attached to cobbles, boulders, and other instream structures at a depth of 4
to 24 inches and in slow to moderately flowing water as low as 9.8° C (Storer 1925,
Zweifel 1955, Lind et al. 1996, Lind unpublished data). Hatching occurs five days to 3
weeks after the eggs are laid depending on water temperature. Tadpole stage occurs
from May through September.
CALIFORNIA RED-LEGGED FROG (RANA AURORA DRAYTONII; FT, CSC)
USFWS listing of the California red-legged frog (CRLF) as a threatened species under
the ESA was effective on June 24, 1996. On March 13, 2001, a designation of critical
habitat was made for the CRLF (USFWS 2001). A recovery plan for CRLF was issued
by USFWS in February 2002 (USFWS 2002). The objective of the recovery plan is to
reduce threats and improve the population status of CRLF sufficiently to warrant
delisting. CRLF critical habitat was revised between 2004 and 2010, with the Final Rule
for the Revised Designation of Critical Habitat for California Red-Legged Frog being
issued on March 17, 2010. The primary constituent elements of critical habitat for CRLF
are aquatic and upland areas where suitable breeding and non-breeding habitat is
interspersed throughout the landscape and is interconnected by unfragmented dispersal
habitat. To be considered critical habitat, an area must include two (or more) suitable
breeding locations, a permanent water source, associated uplands surrounding these
water bodies up to 300 feet from the water’s edge, all within 1.25 miles of one another
and connected by a barrier free dispersal habitat that is at least 300 feet wide. Breeding
locations consist of quiet streams and permanent, deep, cool ponds with overhanging
and emergent vegetation below 4,000 feet above mean sea level (msl). CRLF is known
to occur adjacent to breeding habitats in riparian areas and heavily vegetated
streamside shorelines, and non-native grasslands.
Sierran streams historically supported populations of red-legged frog; however, these
populations have been eliminated. The CRLF is threatened by a variety of human
activities. These include destruction or degradation of habitat by urbanization,
agriculture, construction of reservoirs, mining, livestock grazing, timber harvesting, and
February 2011 B-11