Wildlife Specialist report

The literature documents that a large number of amphibians and reptiles are killed on
roadways (Maxwell and Hokit 1999). Fahrig et al. (1995) documented that the higher the
traffic intensity, the greater the number of dead frogs and toads. OHVs have also been
documented to cause direct mortality (Maxwell and Hokit 1999). Motor vehicles on roads
and OHVs also affect habitat quality, habitat fragmentation, and herpetofauna have even
been documented to suffer from vehicle noise. Soil disturbance can negatively affect
amphibians and reptiles. Temporary pools of water on roadways have been documented
to negatively affect amphibians. Voss and Chardon (1998) documented that Moor Frog
populations were negatively affected by density of roads within 250 meters of waterways.
Semlitsch (1998) found that some species used and dispersed within 250 meters of
riparian, wetland and aquatic habitats.
Effects to reptiles and amphibians can be grouped into two analysis factors:
1. A greater potential for harvest, and/or
2. Disturbance effects.
Harvest effects were analyzed by miles of roadway within each habitat type and
disturbance effects were analyzed by distance from road within the identified associated
habitat out to 250 m (acres).
The effects were determined by using an approach that analyzed the change in habitats
that focal species are associated with between the different alternatives. These selected
species reflect general habitat conditions needed by other reptiles and amphibians with
similar habitats. There is an exception to this approach of using habitat association as the
analysis area. For the federally listed Chiricahua leopard frog, the analysis examined the
change in miles of road within dispersal distances of extant populations (the dispersal
distance identified by the FWS), and the change in the number of road stream crossings
within this zone (table 78).
Chiricahua Leopard Frog [(CLF)/Federally “Threatened” Species] – Aquatic habitats
used by this species include a variety of natural and human-constructed waters between
elevations of 3,281 and 8,890 feet. Aquatic habitats include rivers, permanent streams and
permanent pools in intermittent streams, beaver ponds, cienegas (i.e., wetlands), springs, and
earthen livestock tanks. They are also occasionally found in livestock drinkers, irrigation
sloughs or ditches, wells, abandoned swimming pools, ornamental ponds, and mine adits
(Southwest Endangered Species Act Team 2008).
On the Gila National Forest, 15 occupied sites in 2009. Compared to many of the other
federally listed species in the Region the concern for this species within its historic range
is relatively high. The low number of occupied sites on the Gila adds to this concern.
This species has a complex life cycle consisting of eggs and larvae that are entirely aquatic
and adults that are primarily aquatic (Southwest Endangered Species Act Team 2008). Each
stage of the frogs’ life history has its own set of environmental or habitat requirements that
influence its susceptibility to changes in its habitat, but in general Chiricahua leopard frogs
need permanent to semi-permanent water that is free, or nearly so, of non-native aquatic
predators (Southwest Endangered Species Act Team 2008). However, frogs are known to
57