Wildlife Specialist report

thrush species, and the red-breasted nuthatch were associated with larger forest patches
(Keller and Anderson 1992, and Brand and George 2001).
Roads and motorized trails reduced forest bird reproduction up to a distance of 200 m.
adjacent to a major highway (Foppen and Reijnen 1994). As analysis for the Travel
Management project on the Gila National Forest deals with secondary roads with much
less traffic than primary roads, this distance should be interpreted with caution. However,
in a study investigating forest cover on the movements of forest birds, Belisle et al.
(2001) supported that forest birds’ movements are constrained when they travel in
deforested or fragmented landscapes. Fragmentation as a result of forest roads can
therefore be interpreted to degrade remaining forest habitat, in which breeding success is
thereby decreased (Belisle et al. 2001, Burke and Nol 1998, Payne and Payne 1993, and
Haas 1998). Miller et al. (1998) found that the majority of species in both forested and
grassland habitats were disturbed by trails in a zone of influence up to 100 m. Marzluff
(1997) hypothesized that changes in songbird abundance in response to roads in
southwestern ponderosa pine forests were beneficial to some species (Corvids, juncos and
finches), but would moderately decrease abundance of robins, warblers, tanagers,
grosbeaks and song sparrows. In addition, roads and recreation trails may fragment forest
patches and increase nest predation and parasitism rates by species such as cowbirds and
gray jays (Hickman 1990, Miller et al. 1998, and Gutzwiller et al. 2002). The focal
species used for the analysis are the plain titmouse, gray vireo, white-eared hummingbird,
and Costa’s hummingbird. To analyze effects to this guild of species from the proposed
action and each alternative of the Travel Management Project on the Gila National Forest
analysis will focus on two factors:
1. To analyze the potential for harvest/direct disturbance effects of motorized
activities to songbird/birds from forested and grassland areas road densities within
forest and grassland, vegetation cover types were measured, as these densities
pertain to the proposed action and each alternative.
2. To analyze disturbance/indirect effects, a disturbance zone of 100 m. from roads
within forested and grassland vegetation cover types was used as it pertains to the
proposed action and to each alternative.
Plains titmouse (Management Indicator Species, and Forest Service Sensitive
Species Representative of Pinyon_Juniper/Shrub-Oak Woodland Habitat Cover
Type) - The plain titmouse is an indicator of pinyon-juniper/shrub-oak woodland
habitats. The plain titmouse inhabits evergreen trees in dry woodlands of the southwest
(USDA 1991). It usually builds nests in natural cavities or old woodpecker holes,
primarily in oak trees but it is capable of excavating its own cavity in rotted wood. Trend
estimates on the forest indicate an increasing trend in Plain Titmouse on the GNF.
Limiting factors for the Plain Titmouse include cavities in snags and hollow trees. With
approximately 1,643,096 acres of woodland vegetation type on the Gila National Forest,
cavities are expected to be abundant for this species.
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