© 2001 Henk Wallays (1 of 17)
Aneides ferreus Cope, 1869
Nancy L. Staub1
1. Historical versus Current Distribution. Clouded salamanders (Aneides ferreus) are found in the coastal forests of Oregon and northern California. Their range extends from the Columbia River south through the Siskiyou and Coast mountains and western Cascades of Oregon (but they are not found in the extreme northwestern part of the Coast Mountains) and northwestern California. In California, their range extends to near the junctions of Hurdygurdy Creek and Goose Creek with the South Fork of the Smith River near the coast, and north of the junction of the Salmon and Klamath rivers further inland (Leonard et al., 1993; Wake and Jackman, 1999 ). The current distribution of the clouded salamander is much more restricted than previously thought because all British Columbia specimens and most specimens from California have been assigned to the new species Aneides vagrans (wandering salamander; Wake and Jackman, 1999 ).
Clouded salamanders occur in high densities in old growth forests (Corn and Bury, 1991) and in recently cut or burned areas in association with stumps, decaying logs, and coarse, woody debris (Van Denburgh, 1916; Fitch, 1936; McKenzie and Storm, 1970; Whitaker et al., 1986; Bury and Corn, 1988b; Welsh and Lind, 1988, 1991). Welsh and Lind (1988) found that mesic forest stands had significantly higher capture rates of clouded salamanders than did drier stands. This species tends not to be found in dense forests (Wood, 1939). Individuals have been found ≤ 1,525 m elevation (Beatty, 1979). Populations have certainly been lost due to forestry management practices and urban sprawl.
2. Historical versus Current Abundance. Clouded salamanders are typical inhabitants of old growth forests (Corn and Bury, 1991), especially in edge habitats (e.g., forest clearings) with downed or standing decaying trees and stumps. Populations associated with post-logged areas eventually decline, and it is doubtful that this species can survive in areas where forests are intensively managed on short rotation cycles because of severe reduction in moisture conditions and the amount of large woody debris (Corn and Bury, 1991). The amount of coarse, woody debris retained after timber harvesting under current forest management guidelines probably does not provide adequate habitat for clouded salamanders (Butts and McComb, 2000).
3. Life History Features.
A. Breeding. Reproduction is terrestrial.
i. Breeding migrations. Do not occur. Females lay eggs in late June and July, and hatchlings emerge in late August or September (Petranka, 1998).
i. Breeding habitat. In rotting logs and possibly in the forest canopy.
i. Egg deposition sites. Egg clutches have been found in rotting logs (Storm, 1947).
ii. Clutch size. Reported clutch sizes vary from 9–17 eggs (Storm, 1947). An ovarian count reported 12 eggs (Fitch, 1936).
C. Direct Development.
i. Brood sites. If the reproductive biology of the clouded salamander is similar to that of the wandering salamander, brood sites occur in the forest canopy as well as in decaying logs (Welsh and Wilson, 1995).
ii. Parental care. Apparently variable. Clutches have been found without a parent in attendance (A. ferreus; Storm, 1947), with a female in attendance (A. vagrans; Dunn, 1942), and with both a male and a female in attendance (A. ferreus; Storm, 1947).
D. Juvenile Habitat. Juvenile clouded salamanders prefer bark litter over rock or leaf litter (McKenzie and Storm, 1970). Subadults select bark litter at higher temperatures (20 ˚C, 25 ˚C) and show no preference between rock or bark litter at lower temperatures (10 ˚C; McKenzie and Storm, 1970). McKenzie and Storm (1971) demonstrate that as juvenile animals become older their color patterns become darker and duller.
E. Adult Habitat. Adults are found associated with stumps and logs in Douglas fir forests, crevices in rock outcrops and road cuts, and talus (Van Denburgh, 1916; Wood, 1939; Lowe, 1950; Nussbaum, 1983; Maser and Trappe, 1984; Leonard et al., 1993; Jackman, 1999 ). Animals are most commonly found in decaying logs and stumps with intact bark—either under the bark, within the log, or under the log (Bury and Corn, 1988b; Corn and Bury, 1991). Habitats with such logs are often associated with forest edges (Myers and Maslin, 1948; Stebbins, 1951). For example, McKenzie and Storm (1970) found clouded salamanders in stumps and fire-charred logs of Douglas fir associated with forest clearings and road banks. The preferred type of wood is Douglas fir; individuals are found less commonly in Port Orford cedar, alder, and redwood (Myers and Maslin, 1948; Wake, 1965). Individuals have been found ≤ 6.1 m above the ground in dead stumps (Van Denburgh, 1916; Slevin, 1928). Based on recent work documenting the presence of the wandering salamander in the forest canopy, it is probable that the clouded salamander occupies similar habitat in its range (J.C. Spickler, personal communication). In a microhabitat selection experiment, adults consistently selected against leaf litter and showed equal preference for bark litter and rock (McKenzie and Storm, 1970). Jackman (1999 ) suggests that there may be a difference in habitat preferences between clouded and wandering salamanders. In northwestern California, clouded salamanders are commonly found associated with both decaying logs and rocky slopes, while wandering salamanders are almost exclusively found associated with decaying logs.
F. Home Range Size. Unknown.
G. Territories. In contrast to wandering salamanders, clouded salamanders appear to be relatively aggressive. Thirty-two percent of specimens from an Oregon population had scars, presumably from conspecific attacks, and males had a higher percentage of scars than did females (Staub, 1993). Studies on A. vagrans indirectly suggest that this species may not be as aggressive as is A. ferreus—A. vagrans does not use the chemical signals of fecal pellets to delimit territory boundaries as other plethodontids tend to do (Ovaska and Davis, 1992).
H. Aestivation/Avoiding Dessication. Aestivation is unknown; animals likely avoid dessicating condition by seeking shelter under cover objects or in burrows.
I. Seasonal Migrations. Not known to occur.
J. Torpor (Hibernation). Not known to occur.
K. Interspecific Associations/Exclusions. Clouded and wandering salamanders overlap in a zone < 15 km wide in northwestern California. Jackman (1999 ) reports slight evidence of introgression, but clear hybrid individuals have never been identified. The range of clouded salamanders also overlaps with congeneric black salamanders (A. flavipunctatus; Fitch, 1936; Myers and Maslin, 1948; Stebbins, 1985), especially in the Klamath River valley, but black salamanders occur in hotter, drier regions (for example, further up the Klamath River Valley).
Mitochondrial, allozyme, and karyotypic data distinguish clouded A. ferreus from A. vagrans (Sessions and Kezer, 1987; Jackman, 1999 ). Morphologically, these two species are similar (Beatty, 1979).
L. Age/Size at Reproductive Maturity. Data from McKenzie (1970) suggest that males mature during their second year at lengths greater than 36 mm SVL, and that females first reproduce in their third year when they are approximately 55 mm SVL.
M. Longevity. Unknown.
N. Feeding Behavior. As with most salamanders, clouded salamanders are generalist feeders. Adults primarily eat isopods (sowbugs), hymenopterans (ants), and coleopterans, but their diet also includes an important assortment of other insects (e.g., dipterans, isopterans [termites]), and mites, spiders, pseudoscorpions, centipedes, and millipedes (Fitch, 1936; Storm and Aller, 1947; Bury and Martin, 1973; Whitaker et al., 1986). Whitaker et al. (1986) found no substantial differences between the diets of adult males and females. Hatchlings (< 20 mm SVL) eat small prey, primarily mites, springtails, flies, and small beetles (Whitaker et al., 1986). As juveniles get larger, they switch to eating larger prey items such as sowbugs, larger beetles, and earwigs (Whitaker et al., 1986). Adults occasionally consume shed skin (Whitaker et al., 1986).
O. Predators. Poorly documented, but Petranka (1998) suggests predators of Aneides sp. include mammals, woodland birds, and snakes.
P. Anti-Predator Mechanisms. Several anti-predatory behaviors have been observed in the clouded or wandering salamander when individuals are startled or attacked: crawling away rapidly, immobility, a defensive posture (raising the body and undulating the tail), and flipping around followed by immobility (Fitch, 1936; Brodie, 1977). Skin secretions are thought to be noxious (Brodie, 1977).
Q. Diseases. Unknown.
R. Parasites. One species of nematode has been identified in clouded salamanders (Lehman, 1954; Goldberg et al., 1998c).
4. Conservation. Clouded salamanders occur in high densities in old growth forests, and populations have certainly been lost due to forestry management practices and urban sprawl. It is doubtful that this species survives in areas where forests are intensively managed on short rotation cycles because of severe reduction in moisture conditions and the amount of large woody debris. According to Levell (1997), clouded salamanders are listed as Protected in Oregon.
1 Nancy L. Staub
2 David B. Wake
Literature references for Amphibian Declines: The Conservation Status of United States Species, edited by Michael Lannoo, are here.
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