Wildlife Specialist report

move among aquatic sites and can be found in upland sites, roadside puddles, and habitats
that only hold water briefly during these movements. This emphasizes the importance of
considering the broad spectrum of suitable habitats during project design and effects
analyses.
The recovery plan (USFWS 2007: 24-32) identifies numerous diseases; presently, one of the
most serious of these is chytridiomycosis, a highly virulent pathogen caused by the fungus
Batrachochytrium dendrobatidis (Bd). Chytridiomycosis has been implicated in the deaths of
frogs and the decline and extinction of frog populations (Daszak et al. 1999) including
Chiricahua leopard frogs.
Movement patterns by Chiricahua leopard frogs are not well understood. Active movement
of adult frogs up-and-down a drainage, or directional dispersal of metamorph and subadult
frogs may be in response to deteriorating habitat (i.e., drying of breeding pond), predators
(e.g., conspecifics and gartersnakes), or intraspecific competition (USFWS 2007: 14).
Historically, it is likely that perennial corridors were important for dispersing individual
frogs. In the absence of perennial corridors, movement by frogs is likely facilitated by the
presence of seasonal surface waters (lotic and lentic) and otherwise wet conditions during the
summer rainy season that permit overland movement in typically dry environments (USFWS
2007: 14-15; R. Jennings, pers. comm. 2006). Based on observations of various ranids in
Arizona and New Mexico (USFWS 2007: 14-15), reasonable dispersal distances for the
species are (1) one mile overland, (2) three miles along intermittent drainages, and (3) five
miles along permanent water courses (USFWS 2007: D-2,3), or some combination thereof.
Accurately identifying (1) the action area of a proposed project and (2) whether habitats
occur within the action area where the species is reasonably likely to occur are critical steps
in the process of analyzing if and how a particular action may affect Chiricahua leopard
frogs.
Chiricahua leopard frog Summary - For Chiricahua leopard frogs, defining the action area
of a proposed project must consider the reasonable dispersal capabilities of the species, and
the likelihood/extent of any downstream or upstream effects that might arise from the
proposed action. For this species miles of road within the reasonable dispersal distances
from occupied sites will be the indicator that is used to analyze the potential for harvest
and disturbance under the different alternatives. Reasonable dispersal distances for the frog
from occupied habitats to sites being evaluated for occupancy include: a) within 1 mile
overland, b) within 3 miles along an ephemeral or intermittent drainage, or c) within 5 miles
along a perennial stream, or some combination thereof. The Gila has completed an extensive
amount of survey work for this species over the 9 years; over this period of time the number
of populations on the Gila haves continued to decline as a result of Chytridiomycosis.
Analyzing the change in miles of roads within a reasonable dispersal distance from occupied
sites between the different alternative, along with the analysis of other focal amphibian
species that are dependent on perennial riparian areas will provide the bases need to
determine the potential affects to this species from the different alternative.
Mexican Gartersnake (Forest Service Sensitive Species Representative of Low
Elevation Riparian Vegetation Cover Types) – Despite the variety of terrestrial
habitats that this species has been documented in, Mexican gartersnakes are typically an
aquatic species. They are associated with marshes (rush/bulrush/sedge/cattail), lowland
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