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

Application for New License Middle Fork American River Project (FERC Project No. 2079)
natural water source with a turtle population, structure of the habitat, degree of habitat
disturbance, and the presence of suitable basking sites and refugia (Holland 1991a).
The WPT is almost exclusively found in pool and backwater habitats. Their life history
strategy focuses entirely on still water and low velocity conditions, and individuals are
not well adapted to swiftly flowing currents. In low gradient stream systems, the WPT is
more often observed basking on sediments composed of fines than atop coarse
materials. The presence of potential basking sites, such as large woody debris in
particular, adjacent to or in deep pools with aquatic vegetation can be used to predict
the presence of WPT. As with amphibians, basking is a frequent activity, and adjacent
deep pools with underwater cover sites provide protection from predators. Basking is
an important behavioral adaptation among reptiles that allows them to raise their body
temperature to increase their general activity level. As with other reptiles, the WPT
often basks in open, sunny areas. This species occurs in intermittent and perennial
streams, but permanent streams support larger populations (Holland 1991a). In
California’s Trinity River, favorable habitat for the WPT is characterized by warm, deep,
slow flowing pools with underwater cover and basking sites (Reese and Welsh 1998).
Holland (1991a) reported that this species is often found in quiet backwater habitats in
streams. Such habitats provide shelter from predators and offer basking sites for
thermoregulation. The WPT is uncommon in high gradient streams perhaps because
water temperature, current velocity, food resources, or any combination may limit their
local distribution (Holland 1991a).
Perennial wetlands and slow moving creeks and ponds with overhanging vegetation up
to 6,000 feet; suitable basking sites such as logs and rocks above the waterline. May
occur in appropriate habitat. Study area boundaries are within the known geographic
and elevational range of this species. Known to occur within the watershed on the
Middle Fork American River just south of Ralston Afterbay Dam.
BIRDS
NORTHERN GOSHAWK (ACCIPITER GENTILI; FSS)
The northern goshawk inhabits middle to high elevation mature, dense coniferous
forests throughout the east and west sides of the Sierra. It occurs in the foothills during
winter, in northern deserts in pinyon-juniper woodland, and in low elevation riparian
habitats. Optimal habitat contains trees for nesting, a closed canopy (>50%) for
protection and thermal cover, and open spaces allowing maneuverability. In the Sierra
Nevada, nesting occurs from 2,500 feet in ponderosa pine/mixed-conifer habitat to
10,000 feet in red pine and lodgepole pine habitat (USFS 2001). Nest areas, often in
trees along drainages, are characterized by dense stands of large diameter trees with
interconnected canopies. Nests are usually on north slopes near water in the densest
parts of stands, but close to openings and are placed in live trees, but sometimes snags
(USFS 2001). Nests in live trees are usually placed at or just below the lower portion of
the canopy in a crotch (USFS 2001). Nesting season begins in March. It feeds mostly
on birds, using snags and dead treetops as observation platforms.
February 2011 B-14