Virginia Wildlife Action Plan Rating Tier II - Very High Conservation Need - Has a high risk of extinction or extirpation. Populations of these species are at very low levels, facing real threat(s), or occur within a very limited distribution. Immediate management is needed for stabilization and recovery.

Physical Description - This is a medium-sized salamander with a maximum SVL of 81 mm and a maximum total length of 171 mm (n=140). The tail makes up approximately 50% of the total length. This species is slender with relatively thin legs. The snout is rounded to slightly blunt. The head width is greatest at the corner of the mouth. Slightly protuberant eyes are characteristic in living individuals. The legs are slender and the feet and hands are moderately webbed. There are 18-19 trunk vertebrae. There are typically 1.5-2.5 costal folds between the adpressed limbs. This species is dark gray or brownish with a row of white or yellow spots along the side of the body. There is a tendency to have numerous white or yellowish-white spots on the back. The belly is uniformly gray and the underside of the throat is pinkish. There are usually 17-18 costal grooves. This species has a length from 100-157 mm. The dorsal markings may be profuse to nearly absent and extend onto the sides. Lateral spots are larger and more concentrated than dorsal spots. These spots extend forward onto the cheeks and occasionally the upper jaw; backward slightly onto the tail; and ventrally scarcely onto the venter. The legs are spotted dorsally and ventrally. Cream to pink dominates the throat and extends onto the chest where it darkens, blending into the mostly gray venter. The venter is sometimes spotted, sparsely, with cream spotting. Much of the pattern is retained in preservative with the exception of some dorsal spotting. Coloration in preservative is dark brown to dark gray with the spotting remaining cream-colored. Sexual dimorphism is not apparent except during the breeding season when males have a prominent mental gland. Gravid females are noticeably more rotund than males and nongravid females.

Historical versus Current Distribution - Cow Knob Salamanders (Plethodon punctatus) are restricted to elevations > 850 m on Shenandoah Mountain, Augusta and Rockingham counties, Virginia; Pendleton County and North Mountain in Hardy County, West Virginia; and Shenandoah County, Virginia (Highton, 1972, 1988a). Recent inventories have expanded the known range to include Hampshire County, West Virginia, down to 732 m elevation (Pauley, 1998; R. Highton, personal communication).

Historical versus Current Abundance - Unknown historically. Cow Knob Salamanders apparently are uncommon in many areas of their range but may be abundant at the surface in small pockets associated with ample rock cover and deep soils. Known density estimates range from 0.03–0.54/m2 in Rockingham County, Virginia (Fraser, 1976b), to 1.62/m2 in Pendleton County, West Virginia (Tucker, 1998).

Life History Features - Petranka (1998) has summarized the life history and biology of Cow Knob Salamanders.

Breeding - Reproduction is terrestrial.

Breeding migrations - This species does not migrate. Spermatophores are deposited in early spring. Mating probably occurs in spring and fall. Based on the presence of enlarged follicles, Tucker (1998) thought that egg laying occurs February–April (although R. Highton [personal communication] feels this is unlikely).

Breeding habitat - The breeding habitat of Cow Knob Salamanders is unknown. This species may be more subterranean than other large Plethodon and may mate underground. Pairs of males and females have been found under rocks in spring and fall, suggesting that some mating occurs in the forest floor.

Egg deposition sites - Eggs are deposited beneath rocks or underground in deciduous forest habitats, but no nests have been reported for this species.

Clutch size - From 7–16 eggs.

Direct Development

Parental care - Unknown, but present in all known Plethodon in which nests have been found (R. Highton, personal communication).

Juvenile Habitat - Young of the year emerge on the surface in September. No special habitat characteristics are known for juveniles, and they are apparently the same as adult habitat characteristics.

Adult Habitat - Cow Knob Salamanders have been observed in hemlock (Tsuga canadensis) stands, old-growth hardwoods, and mature hardwoods. They do not appear to be restricted to any one forest type as long as forest floor and subterranean features and canopy cover are present (Green and Pauley, 1987; Buhlmann et al., 1988; Tucker, 1998). Adults and juveniles are most commonly found under rocks in moist areas in deep soil on north-facing slopes above 914 m. This species had been found most often in mature and virgin hardwood forest patches. Individuals occasionally are found in younger hardwoods but not in pine forests, young hardwoods, or clearcuts.

Home Range Size - Unknown. Movements are probably only a few meters in the lifetime of an individual. Buhlmann et al. (1988) reported movements of < 2m to 17.4 m. Tucker (1998) recaptured one individual that had moved 0.9 m.

Territories - The territorial behavior of this species has not been studied.

Aestivation/Avoiding Dessication - Surface abundance of Cow Knob Salamanders is influenced by environmental conditions (Buhlmann et al., 1988; Tucker, 1998). Adults and juveniles are active during cool, wet periods in the spring (April–June) and autumn (September–October). Individuals remain underground during warm, dry months.

Seasonal Migrations - This species does not exhibit seasonal migrations.

Torpor (Hibernation) - Cow Knob Salamanders apparently are inactive November–March when surface temperatures are at or near freezing.

Interspecific Associations/Exclusions - Other salamanders that occur sympatrically with Cow Knob Salamanders are Jefferson Salamanders (Ambystoma jeffersonianum), Spotted Salamanders (Ambystoma maculatum), Allegheny Mountain Dusky Salamanders (Desmognathus ochrophaeus), Spring Salamanders (Gyrinophilus porphyriticus), Four-toed Salamanders (Hemidactylium scutatum), Eastern Newt (Notophthalmus viridescens) efts, Eastern Red-backed Salamanders (Plethodon cinereus), White-spotted Slimy Salamanders (Plethodon cylindraceus), Shenandoah Mountain Salamanders (Plethodon virginia), and Red Salamanders (Pseudotriton ruber; Mitchell et al., 1999). Fraser (1976a,b) determined that there was little competition between juvenile and adult Cow Knob Salamanders and adult Shenandoah Mountain Salamanders (then recognized as Valley and Ridge Salamanders; Plethodon hoffmani) for food and habitat characteristics. White-spotted Slimy Salamanders have been found syntopically with Cow Knob Salamanders (Pauley, 1995b, 1998; Mitchell, 1996; Tucker, 1998), but interactions with this larger Plethodon have not been studied.

Age/Size at Reproductive Maturity - Sexual maturity is reached in about 3 yr after hatching (Fraser, 1976a), when males are approximately 49 mm SVL and females are 59 mm SVL (Tucker, 1998).

Longevity - Length of life is unknown but is probably similar to that of other large Plethodon—about 15 yr (Snider and Bowler, 1992).

Feeding Behavior - Cow Knob Salamanders are opportunistic carnivores on and above the forest floor during wet conditions. Most active foraging apparently occurs at night. Individuals have been observed to climb on tree trunks and rocks at night (Buhlmann et al., 1988). It is unknown whether foraging takes place under leaf litter or underground during dry periods, but it is likely that most energy consumption occurs during wet weather, as in other terrestrial salamanders.

Adults and juveniles prey on a wide variety of invertebrates, including ants, collembolans, beetles, dipterans, coleopterans, orthopterans, insect larvae, millipedes, centipedes, spiders, and mites (Fraser, 1976b; Tucker, 1998). The size of the prey item is positively correlated with the size of the salamander.

Predators - Not reported, but Petranka (1998) suggested shrews, small birds, woodland snakes, opossums, and skunks.

Anti-Predator Mechanisms - Mechanisms to fend off predators are unknown, but mucous secretions in the tail may inhibit swallowing by small predators such as snakes (e.g., Diadophis sp. and Lampropeltis sp.) and shrews.

Diseases - No diseases have been reported in this species.

Parasites - Cepedietta michiganensis (a protozoan) and Batracholandros magnavilvaris (a nematode) are known to occur in the digestive tract (Tucker, 1998), but the etiology of these parasites is unknown.

Conservation - The George Washington National Forest, in which most of the range of Cow Knob salamanders occurs, recognizes this as a Sensitive species. Most of the land > 914 m has been allocated to Management Area 4 (areas off limits to logging) and has been designated as the Shenandoah Mountain Crest Special Biological Area. A formal Conservation Agreement exists, via a Memorandum of Understanding between the George Washington National Forest and the U.S. Fish and Wildlife Service, that affords the habitat of this species on public lands some protection from logging and other potentially damaging operations (Mitchell, 1994b). Cow Knob Salamanders are listed as a Species At Risk by the U.S. Fish and Wildlife Service and a Species of Special Concern in Virginia and West Virginia (Mitchell et al., 1999). Cow Knob Salamanders may be threatened by logging operations and the loss of hemlock trees by the introduced hemlock woolly adelgid (Adelges tsugae), and potentially threatened by defoliation of canopy hardwood trees by the introduced gypsy moth (Lymantria dispar).

• Altig, Ronald & McDiarmid, Roy W. 2015. Handbook of Larval Amphibians of the United States and Canada. Cornell University Press, Ithaca, NY. 341 pages.
• AmphibiaWeb. 2020. University of California, Berkeley, CA, USA.
• Dodd, C.K., Jr., Linzey, D.W. (Ed.), 1979, Cow Knob salamander, Proc. Symp. on Endangered and Threatened Plants and Animals of Virginia, pg. 387-388, 665 pgs., Ext. Div., Virginia Polytechnic Institute and State Univ., Blacksburg
• Martof, B.S., Palmer, W.M., Bailey, J.R., Harrison, III J.R., 1980, Amphibians and Reptiles of the Carolinas and Virginia, 264 pgs., UNC Press, Chapel Hill, NC
• Terwilliger, K.T., 1991, Virginia's endangered species: Proceedings of a symposium. Coordinated by the Virginia Dept. of Game and Inland Fisheries, Nongame and Endangered Species Program, 672 pp. pgs., McDonald and Woodward Publ. Comp., Blacksburg, VA