Dames & Moore, 1999 - USDA Forest Service

portal itself. Bats were not observed anywhere else at the Site or the surrounding area during the September
1997 surveys, but large numbers were observed at the ballfield in July (personal communication with Steve
Arnett, Dames & Moore, 1997). Bats may have been less active in September than July because of the
cooler temperatures and damper weather. Due to the timing of the survey, data were not collected on the
use of the Site by breeding bats. Although warmer environmental conditions are generally required for
maternity roosts, no conclusions can be made from the existing literature or bat expert knowledge as to the
potential presence or absence of breeding bats at the Holden Mine Site.
During the general surveys, mammal species commonly observed included Douglas squirrel, mule deer,
chipmunks (yellow pine and/or Townsend's), and golden-mantled ground squirrels. Except for black bears,
no predators were observed. Given the ample prey base, predators are expected to use the area regularly.
However, these species are secretive by nature and can easily avoid detection at the Site, as thick cover is
available, and only a relatively small area is used by humans. A complete list of all mammals observed is
provided in Table 4.6-10 by survey area. Observed animal species of special note are listed below by
habitat.
~orth-~spect Coniferous Forest and Mine Workings
Small mammals were common, including both Douglas squirrels and chipmunks. Pikas and their hay piles
were observed on the west and east waste rock piles.
South-Aspect Conifer Stands and Open Areas
High on the ridge deer sign was common, and the remains of a fresh deer carcass suggested the presence
of mountain lion andlor coyotes.
Upstream Riparian
Mule deer and a bear were observed in the shrubby cover along the Holden Lake trail, as well as numerous
chipmunks, Douglas squirrels, and golden-mantled ground squirrels.
Downstream Riparian
Bear and deer sign were common.
Tailings Piles
Deer tracks and deer pellets were observed on the tailings, especially where the cover was somewhat better
established. Golden-mantled ground squirrels and chipmunks were also observed in these areas.
A variety of mammals are expected to use the tailings pile and Railroad Creek. However, with the
exception of small mammals, most of these species would not use these areas exclusively as they are highly
mobile and have large home ranges. Species which,might live exclusively on the tailings piles include
golden-mantled ground squirrel, chipmunk spp., deer mouse, and bushytail woodrat. Species potentially
inhabiting the riparian zone exclusively, include the aforementioned small mammals as well as vole spp.,
Pacific jumping mouse, and beaver. Additionally, all the species listed in Table 4.6-9 as potentially present
in the Site area may use the tailings areas to some degree.
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'17693-005619~uly 19.19994:51 PM:DRAFT FINAL IU REPORT