Wildlife
Military training can reduce wildlife populations indirectly by damaging soils and
vegetation that could lead to altered plant communities that are unsuitable as habitat for the
wildlife species that once used them (Trame, 1997). Dismounted military training can flush
or startle small mammals, ground nesting birds, and reptiles. This could lead to increased
predation on young or the displacement and death of eggs or young. Impacts to
reproductive success can cause decreased populations (Trame, 1997). Mule deer, elk,
pronghorns, and many species of raptors are more readily flushed or displaced by
pedestrians than by moving vehicles. Wildlife species can be affected by mounted military
training through direct disturbance and by the indirect alteration of their habitat. Small
animals that den, nest, or live exclusively on the ground can suffer death from maneuver
training. The eggs and young of ground-nesting birds can be destroyed. Human presence
and noise from training exercises could disrupt wildlife species from foraging or
reproducing. For example, some raptors abandon nests or territories as a result of human
presence in the vicinity (Trame, 1997). Limited research exists on the indirect, habitat-related
impacts of mounted military training on reptiles, amphibians, or aquatic species (Trame,
1997). However, military training results in the creation of two-track roads and wider corridors

cleared of vegetation. The effects of these types of vegetation removal and surface
disturbance on wildlife have been studied extensively and are discussed in existing
literature (Gutzwiller, 1991; Trombulak and Frissell, 2000; Wisdom et al., 2000; USDI and
USDA, 2001; Ingelfinger, 2001; Mader, 1984; Merriam et al., 1989; Oxley et al., 1974; Gibbs,
1998; and Busack and Bury, 1974). Impacts to wildlife from activities at the Live
Hand-grenade Range would include local disturbance of habitat and possible mortality that
are similar to impacts associated with training activities previously described.

Birds
Factors influencing the impacts of military training maneuvers on bird populations include
changes in vegetation structure, composition, and development from military maneuvers;
the response of birds to changes in vegetation characteristics at many different scales;
training-related behavioral changes that can lead to site abandonment or colonization; the
seasonal timing of training activities; total displacement of sensitive or secretive species; and
attraction of exotic and disturbance-tolerant species to disturbed areas (Trame, 1997).
Studies on changes in the avian community in response to military training for Fort Carson,
which has grassland and pinyon-juniper habitat types similar to those on the PCMS,
indicate that overall biomass and abundance of prairie habitats were not substantially
decreased compared with control sites. However, the biomass of seed-eating, open-field
species was higher on the training site, while the biomass of omnivorous, open-field species
was higher on the undisturbed control site (Trame, 1997).
Destruction of trees, shrubs, and ground cover in forests leads to major changes in habitat
structure and results in relatively substantial changes in bird abundance and community
composition. The general result is an increase in open-field, edge, or disturbance-adapted
species and a decrease in secretive, woodland, and/or ground-feeding species (Trame,
1997). Overall reduction of vegetation can also lead to a decrease in the prey base for raptors
and other predators (Trame, 1997).

Migratory Birds
Most species in the PCMS grassland habitats nest on the ground. Most birds on the PCMS
breed from mid-April to mid-July. Nesting begins in mid-April for several species and is
well underway for most species by mid-May. Eggs and nestlings can be destroyed by
vehicular traffic, and concentrated training activities can cause abandonment of territories
and nests. By mid-fall, most young-of-the-year would be out of their nests, though some
species would continue to nest into fall (USFWS, 1991). Songbirds are particularly
susceptible to noise. Male neotropical migrant birds that breed in short-grass prairie,
sagebrush, and riparian communities use songs to establish and defend breeding territories
and attract females. The volume and frequency of the noise interferes with this ability
(Luckenbach, 1975; Luckenbach, 1978; Memphis State University, 1971; and Weinstein,
1978). Waterfowl have been shown to be distressed enough by helicopter overflights to
flush, and in some cases normal feeding behavior was substantively disrupted (Trame,
1997). The area of disturbance would vary by species and training activity. Concentrated
training activities could cause birds to abandon territories and nests. Limits on military
training during the breeding season could have the effect of minimizing impacts to the bird
community. Part of the Army’s regular practice is to minimize or avoid damage to nesting
birds as much as possible. At the PCMS, mowing of road shoulders and prescribed burns are restricted

to the extent possible during the nesting season. Power lines are also surveyed
for bird electrocutions (Klavetter, 2006).

Raptors
Many raptors are intolerant of high levels of human activity, especially during the breeding
season (April through June). When disturbed by humans (on foot and in a vehicle), by a gas-operated
engine, or the sound of a rifle, fewer ferruginous hawks had successful nests and
fewer young fledged from those nests (Trame, 1997). Some species of raptors can habituate
to high levels of human activity. Short-term impacts to raptors from military training on the
PCMS have been documented, including nesting failures, lowered nesting success,
displacement, and changes in wintering distribution and behavior (Andersen et al., 1990
and Fyfe and Olendorff, 1976). It is possible these short-term responses can lead to long-term
community changes, such as changes in breeding density and species composition.
Resident raptors located in the area where military training occurred shifted the center of
their home range and activity areas, made movements outside of the areas they had
previously used, and increased the size of the area they used. Birds located in areas not
exposed to training did not exhibit these changes to the same extent. In general, birds
appeared to increase the size of their home range during periods of military activity. An
alternative response to disturbance might have been to seek out areas within the home
range but isolated from the disturbance.
Jet overflights on the PCMS have not been shown to influence nesting success of red-tailed
hawks. Over a period of time, these birds habituate to low-level air traffic and avoidance
behavior decreases. Golden eagles prefer to nest away from human disturbances, including
roads, and have reduced nesting success in nests located closer to roads than in nests farther
from roads (Fernandez, 1993). Part of the Army’s regular practice is to identify golden eagle
nest sites annually and establish 1,640 feet (500-meter) buffers around each nest site.
Training activities are restricted in these buffer zones from April through June (USFWS,
1991). Usually these buffers can be accommodated during training exercises, but in some
cases training could require encroachment on this buffer area. The G-3 coordinates with
DECAM wildlife biologists before each exercise to devise a training plan that minimizes
potential impacts to nesting birds.

Small Mammals
Impacts from military training on small mammals are similar to those on bird communities;
species adapted to reduced vegetation, bare ground, or disturbance are favored, while more
sensitive woodland species or those requiring intact short-grass prairie ecosystems decline.
Studies of small mammal community composition at Fort Carson indicate that, in prairie
habitats, small mammal species that prefer sandy soils and eat seeds of weedy plants
replaced other species.

Pronghorn
Studies conducted on the PCMS indicate that movements or temporary shifts in home
ranges caused by military training activities did not have measurable effects on pronghorn
productivity or physical condition at the PCMS (Gerlach and Vaughan, 1990). Pronghorn
groups have been alarmed by low jet and helicopter overflights at the PCMS. This could
contribute to reduced winter survival rates, the poor condition of individuals entering the
breeding season, reduced reproductive success and recruitment, and eventual population
declines (Trombulak and Frissel, 2000 and Wisdom et al., 2000). Pronghorn are especially

vulnerable during fawning season (May 1 to June 30) and during severe winters (USFWS,
1991). Restricting training during these periods could have the effect of reducing impacts to
pronghorn. Revegetating disturbed areas and areas around water with a mix of native
shrubs, grasses, and forbs; and maintaining water guzzles and windmill sites as open water
sources could also have the effect of reducing impacts from military training on pronghorn
(Klavetter, 2006 and Gerlach and Vaughn, 1990). Hunting on the PCMS is regulated by
CDOW and, with input from DECAM wildlife staff, is used as a tool to manage pronghorn
populations on the installation.

Mule Deer
One study of mule deer demonstrates that if harassed, mule deer exhibit increased overall
activity levels, increased use of cover, increased sensitivity to vehicles, increased flight
distance, and decreased reproduction the following spring (Yarmology, et al. 1988 and
Trame, 1997). Mule deer may habituate to maneuvers and off-road vehicles if they are not
actively pursued (Trame, 1997). In severe winters and during late gestation and lactation
periods, helicopter disturbance could adversely affect deer (USFWS, 1991). Training
restrictions during severe winters and the fawning season (June 20 to August 20) could
minimize impacts to mule deer. Fawns are especially vulnerable at this time to mortality
from accidents, abandonment, increased predation, and depletion of energy reserves from
excessive movement. Revegetating disturbed areas could also have the effect of reducing
impacts from military training on mule deer (USFWS, 1991). Hunting on the PCMS is
regulated by CDOW and, with input from DECAM wildlife staff, is used as a tool to manage
mule deer populations on the installation.

Coyote
Coyotes are moderately affected by military training. Most changes in coyote movement
from military activity are temporary, and coyotes resume their previous activity patterns
and occupy similar home ranges after military activity ends (USFWS, 1991). Restricting
military training during denning and other critical times for coyotes, and rehabilitating
disturbed habitat could have the effect of maintaining the coyote prey base and escape cover
(USFWS, 1991).

Swift Fox
Direct impacts to swift fox caused by military training are minimal. Overall degradation of
shortgrass prairie habitat on a large enough scale would likely result in a localized decline
in swift fox populations (USFWS, 1991).
Sensitive Species
The following impacts to sensitive species from military training on the PCMS currently
occur and would continue to occur under the No Action alternative. Figure 3-4 depicts the
distribution of sensitive wildlife species at the PCMS.

Black-Tailed Prairie Dog
Prairie dog habitat at the PCMS is found in Maneuver Training Areas. Mine plows can
damage active burrows of prairie dogs. Prairie dog burrows usually have multiple entrances
and are generally deeper than the surface disruption associated with mine plows; therefore,
mine plow deployment within a colony would have little long-term effect on the colony.
Prairie dogs could also be affected by off-road vehicles, trench obstacles, and live, small-arms
fire. It is unlikely, however, off-road vehicles would permanently damage burrows or kill the

occupants of a burrow. Damage to burrows or death attributable to trench obstacles
would not be substantial. Live, small-arms fire poses minimal or no threat to prairie dogs.
However, prairie dog burrowing activities on small-arms ranges with electronic targeting
mechanisms have caused problems because of buried electrical power wires. In these cases,
prairie dogs may be controlled according to the practices outlined in the Biological
Assessment and Management Plan for the Black-tailed Prairie Dog on Fort Carson and the PCMS
(DECAM, 2004g). In 2004, black-tailed prairie dogs were removed from the USFWS
candidate species list; however, the PCMS still follows this management plan.

Burrowing Owl
Burrowing owls use active prairie dog colonies and other burrows on the PCMS. Military
training impacts to burrowing owls would be similar to those of prairie dogs.
Identifying prairie dog towns occupied by burrowing owls annually and establishing a an
approximate 330 to 980 feet (100- to 300-meter) radius buffer around nest sites could have
the effect of reducing impacts from military training on burrowing owls (Partners in Flight,
2000). Usually, these buffers can be accommodated during training exercises, but in some
cases training may require encroachment of this buffer area. The G-3 coordinates with
DECAM wildlife biologists before each exercise to devise a training plan that minimizes
potential impacts to nesting birds.

Mountain Plover
Dismounted troops and off-road vehicle traffic are the greatest threats to mountain plovers
in Maneuver Training Areas. People walking across the prairie or exiting vehicles caused
mountain plovers to perform their distraction display, or flush and fly a short distance.
Plovers rarely responded to military convoys and other traffic by flushing unless the plovers
were near the roadway. Vehicles traveling cross-country, including travel adjacent to roads,
could kill juveniles sheltered in tall vegetation adjacent to the road and destroy nests on the
open prairie. Prolonged human presence near breeding territory would likely disrupt egg
incubation or chick brooding, resulting in death of the eggs or chicks (Bunn et al., 1996).The
effect of military helicopter overflights on nesting mountain plovers is unknown. The
mountain plover was proposed for listing as a threatened species in 1999, and in 2003, the
USFWS withdrew the proposal. Because the mountain plover is no longer proposed for
listing, the Biological Assessment and Management Plan for the Mountain Plover on Fort Carson
and the Pinon Canyon Maneuver Site (DECAM, 2002d), which required an approximate
660 feet (200-meter) radius buffer zone around each mountain plover nest site, is no longer
in force. The Army, however, does maintain these buffers during training exercises, but in
some cases, training may require encroachment on this buffer area. The G-3 coordinates
with DECAM wildlife biologists before each exercise to devise a training plan that
minimizes potential impacts to nesting birds. Buffer zones can be cordoned off using
engineering tape attached to metal fencing posts, by placing painted automobile tires
around the perimeter with off-limits signs attached, or by placing certified weed-free straw
bales with appropriate signage around off-limits areas (DECAM, 2002d).

Bald Eagle
Impacts to the bald eagle from military training are primarily related to the availability of
black-tailed prairie dogs as prey. No training restrictions are associated with the
management of the bald eagle. Bald eagles are sensitive to human disturbance, including
military training. Fewer wintering bald eagles have been found in areas with high human
activity compared to areas with moderate human activity. Appendix E, Attachment E.3
provides a management plan for wintering bald eagles on the PCMS.
Triploid Checkered Whiptail
Impacts to triploid checkered whiptails from military training would be similar to those
described for small mammals and ground-nesting birds. Habitat could be disturbed and
animals might be killed as a result of training maneuvers.

Plants
Available information on the distribution of sensitive plant species known to occur at the
PCMS is limited. Dwarf indigo has been confirmed in Taylor and Spring Canyons; rayless
goldenweed occurs in upper Burke, Taylor, and Van Bremer Arroyo watersheds and near
Brown Sheep Camp; and round-leaf four o’clock occupies south-central portions of the
PCMS (DECAM, 2002a and Schulz and Shaw, 1992) (see Figure 3-5). Pueblo goldenweed
and round-leaf four o’clock occur together within Maneuver Training Areas and
Dismounted Training Areas on a small knoll in the southwestern part of the PCMS known
as Gilligan Island (Klavetter, 2006). Impacts to these and other sensitive plant species from
mechanized and dismounted military training under the No Action alternative would be
similar to the general impacts previously described for vegetation in the particular type or
types of training areas where they occur. These impacts currently occur at the PCMS and
would continue to occur under the No Action alternative.