Van Dyke's Salamander
© 2004 Gary Nafis (1 of 4)
Plethodon vandykei Van Denburgh, 1906
David A. Beamer1
1. Historical versus Current Distribution. The distribution of Van Dyke's salamanders (Plethodon vandykei) is discontinuous, with isolated localities in western and west-central Washington (Brodie, 1970; Wilson et al., 1995; Petranka, 1998). Four disjunct populations are known, including in (1) the Olympic Mountains of western Washington (Clallam, Jefferson, and north-eastern Gray's Harbor counties in Washington); (2) the Willapa Hills of southwest Washington (Pacific and Wahkiakum counties, Washington); (3) the Cascade Mountains of west-central Washington (Pierce, Mason, and Lewis counties, Washington); and (4) southern and west-central Washington (Skamania and Thurston counties). Populations are distributed from sea level to 1,560 m. There is no evidence to suggest that the current distribution differs from the historical distribution.
2. Historical versus Current Abundance. Van Dyke's salamanders are patchily distributed and generally uncommon (Brodie, 1970; Petranka, 1998). They do not fare well in intensively managed forests (Welsh, 1990).
3. Life History Features. Most aspects of the natural history of adult and juvenile Van Dyke's salamanders have not been well documented (Petranka, 1998).
A. Breeding. Reproduction is terrestrial.
i. Breeding migrations. Undocumented, but breeding migrations are not known for any Plethodon species. Courtship and a description of the spermatophore are described by Lynch (1987).
ii. Breeding habitat. Unknown.
B. Eggs. A female collected on 17 April from Lewis County, Washington, contained eggs (2.6 mm in diameter), and a female collected on 1 July from Pierce County, Washington, contained eggs (2.4 mm in diameter; Stebbins, 1951). A recently deposited clutch (5.3 mm in diameter) was discovered on 21 May in Mason County, Washington (Jones, 1989).
i. Egg deposition sites. Only two nests of Van Dyke's salamanders have been discovered. The first was attached to a moss-covered stone in a damp location (Noble, 1925) and the second was located inside a partially rotted log (85 cm in diameter and 5 m in length) in an old-growth forest on a north-northeast facing slope (Jones, 1989).
ii. Clutch size. Ova counts were 11 and 14 from two females examined by Stebbins (1951). A nest in Mason County, Washington, contained seven eggs (Jones, 1989).
C. Direct Development. Hatchlings range in size from 15–18 mm SVL (Nussbaum et al., 1983).
i. Brood sites. A female in Mason County, Washington, was found brooding a clutch in a rotted log (Jones, 1989).
ii. Parental care. An adult female was found within 4 cm of a clutch discovered in Mason County, Washington (Jones, 1989).
D. Juvenile Habitat. A juvenile from Lewis County, Washington, was collected in rocks with little soil approximately 30 cm from the edge of a river (Stebbins, 1951).
E. Adult Habitat. Van Dyke’s salamanders are found beneath moist stones and moss near running water and seeps (occasionally under bark) associated with coniferous forests (Slater, 1933; Bishop, 1943; Stebbins, 1951; Brodie, 1970). Adults are most active on the surface of the forest floor in spring and fall (Petranka, 1998). Populations generally are found in regions that receive > 1.5 m of annual rainfall and have an upper elevational limit at the lower edge of subalpine forests (Wilson et al., 1995).
In coastal habitats, Van Dyke's salamanders are found associated with rocks or woody debris. In interior forests they generally are found associated with moist talus on north-facing slopes (Wilson et al., 1995).
F. Home Range Size. Unknown.
G. Territories. Unknown.
H. Aestivation/Avoiding Dessication. Van Dyke's salamanders likely avoid desiccating conditions by seeking shelter in underground sites.
I. Seasonal Migrations. Van Dyke's salamanders probably move vertically from forest-floor sites to underground sites in response to seasonal dry and cold conditions.
J. Torpor (Hibernation). Generally unknown, but Van Dyke's salamanders likely avoid cold conditions by seeking shelter in underground sites.
K. Interspecific Associations/Exclusions. Olympic torrent salamanders (Rhyacotriton olympicus), Columbia torrent salamanders (R. kezeri), Cascade torrent salamanders (R. cascadae), Dunn's salamanders (Plethodon dunni), Larch Mountain salamanders (P. larselli), and western red-backed salamanders (P. vehiculum) may be found with Van Dyke's salamanders (Leonard et al., 1993)
At a site in Mason County, Washington, Van Dyke's salamanders are sympatric with western red-backed salamanders and Olympic torrent salamanders (Jones, 1989).
At a site in Pacific County, Washington, Van Dyke's salamanders are sympatric with Dunn's salamanders and western red-backed salamanders (Ovaska and Davis, 1992).
Van Dyke's salamanders can distinguish between burrows marked with feces by western red-backed salamanders. However, Van Dyke's salamanders do not avoid marked burrows nor exhibit aggression towards western red-backed salamanders (Ovaska and Davis, 1992).
Van Dyke's salamanders are generally scarce. In suggesting causes for this rarity, Petranka (1998) offers either narrow habitat preferences or competitive/predatory interactions between Van Dyke's salamanders and other species.
L. Age/Size at Reproductive Maturity. Females generally are larger than males. Males mature at 44 mm SVL, females at 47 mm (Petranka, 1998).
M. Longevity. Unknown.
N. Feeding Behavior. Unknown.
O. Predators. Undocumented, but likely include forest snakes, birds, and small mammals.
P. Anti-Predator Mechanisms. All members of the genus Plethodon produce noxious skin secretions (Brodie, 1977).
Q. Diseases. Unknown.
R. Parasites. Unknown.
4. Conservation. Van Dyke's salamanders are rare, and protected as a State Candidate species for listing by the State of Washington. They are Federally listed as a Species of Concern (Petranka, 1998; Washington Department of Fish and Wildlife's Web site at www.wa.gov). Many populations of these salamanders are on National Park Service lands and are therefore afforded some degree of protection.
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 20 Nov 2018.
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