Wildlife Specialist report

Barriers to Animal Travel or Movement – Preclusion of dispersal, migration, or
other movements as posed by a road itself or by human activities on or near a road
or road network.
Route for competitors and predators – Human induced change in the environment
that provides access for competitors or predators that would not have existed
otherwise.
Physiological Response – Changes in levels of stress hormones and heart rate as a
result of proximity to roads or tails.
Analysis Factors
Knight and Cole (1995) developed a conceptual model of the responses of wildlife to
recreational activities. They grouped recreational impacts into four groups harvest,
habitat modification, disturbance, and pollution. Liddle (1997) grouped road impacts into
three groups: Disturbance type 1 occurs when an animal sees, smells, hears, or perceives
the presence of a human but no contact is made and it may or may not alter behavior;
Disturbance type 2 is when habitat is changed in some way; and Disturbance type 3
involves human actions in which there is direct damaging contact with the animal.
Gaines et al. (2003) grouped Wisdom et al. (2000), Knight and Cole (1991), and Liddle
(1997) classification schemes as described in columns 1 to 3 in Table 7. We’ve further
grouped the analysis factors into harvest/direct affects and disturbance/indirect affects, as
described in column 4 in Table 7.
Table 7: Responses of wildlife to various disturbance factors
Road and Trail Knight and Cole
Liddle Combined Analysis
Associated Factors Recreation Activity
Factors
Disturbance, Displacement,
Avoidance, Harassment
Disturbance Disturbance type 1 Disturbance
Physiological Response Disturbance Disturbance type 1 Disturbance
Habitat Loss and Fragmentation Habitat Modification Disturbance type 2 Disturbance
Negative Edge Effects Habitat Modification Disturbance type 2 Disturbance
Snag and Downed Log
Reductions
Habitat Modification Disturbance type 2 Disturbance
Barriers to Animal Travel or
Movement
Habitat Modification Disturbance type 2 Disturbance
Route for competitors and
predators
Habitat Modification Disturbance type 2 Disturbance
Collisions Harvest Disturbance type 3 Harvest
Harvest or Collection
Facilitated by Motorized travel
Harvest Disturbance type 3 Harvest
Focal Species
Ecologists have used different systems to evaluate the potential effects of an activity on
species (Lambeck 1997 and Millsap et al 1990). The focal species approach is one of
these systems (Lambeck 1997). Focal species are species that are used to represent a
group of species because they are sensitive to a particular activity. Carroll et al. (2001)
and Watson et al. (2001) recently tested this approach for wide-ranging carnivores and
birds (respectively), with favorable results. Research related to road affects to federally
listed and R3 sensitive species in this region of the Forest Service is limited; using the
focal species approach allows the Gila to use literature related to different groups of
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