Jemez Mountains Salamander
© 2009 Christopher R. Newsom (1 of 4)
Plethodon neomexicanus Stebbins and Riemer, 1950
Charles W. Painter1
1. Historical versus Current Distribution. Jemez Mountains salamanders were originally collected and described as Spelerpes multiplicatus (= Eurycea multiplicata; Bailey, 1913; VanDenburgh, 1924; Dunn, 1926; Bishop, 1943) but rediscovered and described as Plethodon neomexicanus by Stebbins and Riemer (1950). Their range is limited to an area of approximately 971 km2 (375 mi2) within Sandoval, Los Alamos, and Rio Arriba counties in north-central New Mexico. Jemez Mountains salamanders are known only from high elevations of the mountains surrounding the caldera of the Valle Grande of the Jemez Mountains (Degenhardt et al., 1996; Petranka, 1998). Knowledge of their current distribution has been greatly expanded from early descriptions (Dunn, 1926; Stebbins, 1951; S.R. Williams, 1973). The current distribution is expected to be similar to their historical distribution.
2. Historical versus Current Abundance. Jemez Mountains salamanders are rare and localized, but common in small areas of suitable habitat. Populations are highly fragmented due to subsurface geology. Historical abundance is unknown but expected to be higher in select areas of early heavy collecting and clearcut logging (Williams, 1972a).
3. Life History Features.
A. Breeding. Reproduction is assumed to be terrestrial, although it has not been observed in the wild.
i. Breeding migrations. Migratory behavior not reported or observed; not believed to occur.
ii. Breeding habitat. Males are sexually active throughout the rainy season (June–August). Females likely brood underground in fall or early spring every other year. Gravid females generally are not collected after 20 August. A gravid female collected in August and kept in the lab deposited eggs in early June the following spring. Fewer than 50% of mature females collected are gravid (Reagan, 1972; S.R. Williams, 1972b, 1973, 1976).
i. Egg deposition sites. Although no egg clutches have been discovered in the wild, it is believed they are laid in the deeply fractured interstices of subterranean, metamorphic rock. The composition of this subterranean habitat has not been fully investigated, although soils comprised of pumice or tuft generally are not suitable. Heavy equipment used during logging may cause compaction of soils and thus destroy suitable breeding habitat.
ii. Clutch size. Average clutch size is 7.7 (5–12; Reagan, 1972), with eggs 6.8–7.3 mm in diameter (S.R. Williams, 1978).
C. Direct Development. Females likely brood underground in fall or early spring every other year. Hatchlings appear on the surface during wet weather in mid July to late August at 15–18 mm SVL. Size at hatching in wild individuals is unknown.
D. Juvenile Habitat. Similar to adult habitat.
E. Adult Habitat. Generally found on loose rocky soils between 2,200–2,900 m (Degenhardt et al., 1996), although individuals have been reported as high as 3,429 m (Whitford and Ludwig, 1976). Mostly found in and under rotting Douglas fir logs or under rocks on flat areas and steep slopes. Slope aspect may face any direction. Macrohabitat is coniferous forest dominated by Douglas fir, blue spruce, Engelmann spruce, ponderosa pine, and white fir with occasional aspen. Deciduous understory shrubs are Rocky Mountain maple, New Mexico locust, oceanspray, and various shrubby oaks (Degenhardt et al., 1996). Rarely observed on the surface at night or during the day and rarely encountered under bark, surface litter, or aspen logs. Subsurface geology, elevation, and moisture are key habitat features (Ramotnik, 1988; Ramotnik and Scott, 1988). Desiccation of habitat (Wiltenmuth, 1997b) and the species’ low critical thermal maximum (33.5 ˚C; Whitford, 1968) are important considerations in any habitat manipulation.
F. Home Range Size. Unknown, although studies suggest home range may be small. Ramotnik (1986) tracked an individual that moved 13 m in 1.5 hr during a light drizzle. Two females implanted with Tantalum-182 wire showed strong site fidelity, returning to the same site after repeated movements of up to 5 m. Painter (2000) reported an individual marked on 3 August 1994 that was recaptured near the original capture site nearly 5 yr (1,831 d) later on 10 August 1999; maximum distance recorded from the original capture site was 1.5 m. Of all movements recorded from recaptured individuals, 37% were fewer than 2 m from the original capture site (range = 0–19.7 m). Data indicate a lack of homing ability in Jemez Mountain salamanders displaced from the original capture site (Ramotnik, 1986).
G. Territories. Unknown. Movements of up to 13 m (Ramotnik, 1986) or 19.7 m (Painter, 2000) are known from marked individuals. Of all movements recorded from marked individuals, 37% moved fewer than 2 m from the previous capture site, and 36% moved fewer than 2 m from the original capture site (Painter, 2000).
H. Aestivation/Avoiding Dessication. Unknown. Individuals are not surface active unless sufficient moisture is available following summer monsoon rainfalls.
I. Seasonal Migrations. Individuals retreat underground in response to seasonal extremes of temperature and dryness.
J. Torpor (Hibernation). Retreat underground after temperatures fall below about 6 ˚C.
K. Interspecific Associations/Exclusions. Unknown.
L. Age/Size at Reproductive Maturity. Sexual maturity is reached at 2–3 yr of age in males, 3 yr in females. Mean SVL of mature males is 54.4 mm; females 55.5 mm (Williams, 1972b). Mean annual growth is approximately 3.7 mm SVL (Painter, 2000).
M. Longevity. Unknown, although based on reproductive data, longevity is expected to be about 10 yr.
N. Feeding Behavior. Feed on a wide variety of invertebrates, including annelid worms, spiders and mites (Arachnida), millipedes, centipedes, snails (Mollusca), and insects, including springtails (Collembola; Reagan, 1972; Painter and Altenbach, unpublished data). Ants (Hymenoptera) and mites comprise about 71% of the diet by percent prey items, while ants, beetles (Coleoptera), and non-ant hymenopterans comprise about 67% of the total volume (Painter, 2000). Most prey are taken while Jemez Mountains salamanders actively forage inside rotted logs.
O. Predators. Western terrestrial garter snakes (Thamnophis elegans; Painter et al., 1999). No other predators have been reported, but individuals are possibly preyed upon by black bears, shrews, and larger ground feeding birds.
P. Anti-Predator Mechanisms. None reported in the literature. Newly captured individuals often respond by tightly coiling the body into a loop with the tail covering the head.
Q. Diseases. Unknown.
R. Parasites. The nematode Thelandros salamandrae (Oxyuroidea) has been reported in 55% (Panitz, 1967) and 41% (Reagan, 1972) of specimens examined.
4. Conservation. The range of Jemez Mountains salamanders is limited to the higher elevations of the mountains surrounding the caldera of the Valle Grande of the Jemez Mountains (Degenhardt et al., 1996; Petranka, 1998). Populations are highly fragmented due to subsurface geology; they are rare and localized, but common in small areas of suitable habitat. Jemez Mountains salamanders are listed as Threatened by the State of New Mexico and as a Species of Concern by the U.S. Forest Service and the U.S. Fish and Wildlife Service.
1Charles W. Painter
Literature references for Amphibian Declines: The Conservation Status of United States Species, edited by Michael Lannoo, are here.
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