Valley and Ridge Salamander
© 2017 Alexander Murray (1 of 11)
Country distribution from AmphibiaWeb's database: United States
Plethodon hoffmani Highton, 1971
David A. Beamer1
1. Historical versus Current Distribution. Valley and Ridge salamanders (Plethodon hoffmani) inhabit the Valley and Ridge Physiographic Province from central Pennsylvania south and southwest to the New River in Virginia and West Virginia. They also occur to the west in the adjacent Appalachian Plateau Physiographic Province and to the east in the adjacent Blue Ridge Physiographic Province (Highton, 1986c; Petranka, 1998). Some populations in northeastern West Virginia and western Virginia that were originally attributed to Valley and Ridge salamanders are now recognized as Shenandoah Mountain salamanders (P. virginia; Highton, 1999a, fig. 4). Their current distribution likely is similar to their historical distribution, but populations have likely been lost due to habitat destruction and alteration.
2. Historical versus Current Abundance. Largely unknown, but data collected by Highton (2003) indicate that populations in Snyder County, Pennsylvania, and Augusta County, Virginia, may have crashed. Additional data from these sites will be needed to determine whether these are true declines or natural population fluctuations. Populations at other sites sampled by Highton (2003) in Virginia and West Virginia appear to be more stable.
3. Life History Features.
A. Breeding. Reproduction is terrestrial. The vasa deferentia are filled with sperm from late September to May. Valley and Ridge salamanders in Maryland and Pennsylvania primarily mate in the spring, although occasionally females are found with spermatozoa in their spermathecae during the fall (Angle, 1969).
i. Breeding migrations. Undocumented, but breeding migrations are not known for any Plethodon species.
ii. Breeding habitat. Unknown.
B. Eggs. In Maryland and Pennsylvania, eggs probably are deposited in April–May (Angle, 1969).
i. Egg deposition sites. Unknown, but as with other members of the P. cinereus group, likely include underground sites and perhaps sites under surface cover objects.
ii. Clutch size. The number of mature ovarian eggs (maximum 4.0 mm diameter) in females from Maryland and Pennsylvania range from 3–8 with an average of 4.6 (Angle, 1969).
C. Direct Development. Eggs probably are incubated for about 2 mo and hatch in late August to September (Angle, 1969).
i. Brood sites. Unknown, but probably include underground cavities or chambers.
ii. Parental care. Unknown, but it is likely that females brood, as with other species of Plethodon.
D. Juvenile Habitat. Juveniles likely stay at the nest site for several months after hatching. They are first found on the surface in March (Angle, 1969).
E. Adult Habitat. In West Virginia, Valley and Ridge salamanders inhabit hillside slopes of mixed deciduous forest with flat stones (Green and Pauley, 1987). Most of the range is dry and well drained (Highton, 1999a).
Valley and Ridge salamanders have been found in two different caves in Greenbrier County, West Virginia. In both caves they were within the twilight zone beneath cover (Cooper, 1961).
F. Home Range Size. Unknown, but small home ranges are typical for Plethodon species.
G. Territories. Unknown.
H. Aestivation/Avoiding Dessication. Few Valley and Ridge salamanders have been collected during the summer (Highton, 1962a; Angle, 1969).
I. Seasonal Migrations. Animals likely make vertical migrations, moving from the forest floor to underground sites with the onset of seasonally related cold or dry conditions, then back up to the forest floor with the return of favorable surface conditions.
J. Torpor (Hibernation). Valley and Ridge salamanders avoid cold conditions by moving to warmer underground sites (Highton, 1962a; Angle, 1969).
K. Interspecific Associations/Exclusions. Valley and Ridge salamanders are usually not sympatric with other members of the P. cinereus group. However, they are sympatric with red-backed salamanders in several different areas including central Pennsylvania and near Monterey, Highlands County, Virginia (Highton, 1972). Most of the range occupied by Valley and Ridge salamanders may be too dry for red-backed salamanders to occupy (Highton, 1972).
Populations of Valley and Ridge salamanders have been found proximate to other members of the P. cinereus group. They are found only 1.9 km away from a site that contains Peaks of Otter salamanders (P. hubrichti). In the vicinity of Bell Knob in Tucker and Grant counties, West Virginia, Valley and Ridge salamanders are found within 3.7 km of Cheat Mountain salamanders (P. nettingi). Southern ravine salamanders (P. richmondi) are known from a locality 0.6 km away from Valley and Ridge salamanders on the other side of the New River in Summers and Raleigh counties, West Virginia (Highton, 1999a).
Valley and Ridge salamanders contact Shenandoah Mountain salamanders (P. virginia) at the northern and southern extremities of Shenandoah Mountain salamanders range. In these areas there are some hybrid populations (Highton, 1999a).
Valley and Ridge salamanders also occur in areas with northern slimy salamanders (P. glutinosus), white-spotted slimy salamanders (P. cylindraceus), and Wehrle's salamanders (P. wehrlei; Highton, 1962a, 1972, 1989).
The following species were associated with Valley and Ridge salamanders in caves in Greenbrier County, West Virginia: cave salamanders (Eurycea lucifuga), long-tailed salamanders, red-backed salamanders (P. cinereus), northern slimy salamanders, newt efts (Notophthalmus viridescens), and Jefferson’s salamanders (Ambystoma jeffersonianum; Cooper, 1961).
L. Age/Size at Reproductive Maturity. Juveniles grow 10–12 mm SVL during their first year and become sexually mature in the autumn, at 2 yr old. At this time, males range in size from 38–44 mm; females are 39–47 mm. Most females will oviposit the year after becoming sexually mature, but a small percentage may require an additional year and first breed when they are nearly 4 yr old. Female Valley and Ridge salamanders have a biennial reproductive cycle (Angle, 1969).
M. Longevity. Unknown.
N. Feeding Behavior. Unknown, but as with other Plethodon species, feeding likely takes place at night under moist conditions. Prey items likely include a range of invertebrates, especially insects.
O. Predators. Unknown.
P. Anti-Predator Mechanisms. All Plethodon produce noxious skin secretions (Brodie, 1977). Valley and Ridge salamanders frequently become immobile when initially contacted. Valley and Ridge salamanders were included in a field study on immobility, however it is not possible to separate their behavior from Shenandoah Mountain salamanders in this published data set. Immobility may increase survival by making the salamander less likely to be detected, especially by visually oriented predators (Dodd, 1989).
Q. Diseases. Unknown.
R. Parasites. Unknown.
4. Conservation. Valley and Ridge salamanders are not protected by any state. Within their range there are many federal and state properties that contain suitable habitat for these salamanders.
As with all species of Plethodon, Valley and Ridge salamanders do not migrate to breeding grounds, and they do not have large home ranges. Thus, they can exist in habitats of smaller size than many other amphibian species. Conservation activities that promote mature closed-canopy forests should benefit this species.
Acknowledgments. Thanks to Richard Highton, who reviewed this account and gave us the benefit of his insight and experience.
1David A. Beamer
2Michael J. Lannoo
Literature references for Amphibian Declines: The Conservation Status of United States Species, edited by Michael Lannoo, are here.
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Citation: AmphibiaWeb. 2018. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 13 Dec 2018.
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