© 2012 Todd Pierson (1 of 44)
Country distribution from AmphibiaWeb's database: United States
Aneides aeneus Cope and Packard, 1881
Thomas K. Pauley1
1. Historical versus Current Distribution. Dunn (1926) described the range of green salamanders (Aneides aeneus) as extending from Nickajack Cave, Tennessee, north to Baileysville, West Virginia, and through the Cumberland and Kanawha sections of the Allegheny Plateau. Bishop (1943) shows them from northern West Virginia south through southwestern Ohio, eastern Kentucky, western Virginia, North Carolina, South Carolina, and eastern Tennessee into northern Georgia and Alabama. Later range extensions included the extreme northeast of Mississippi (Ferguson, 1961b), southeastern Pennsylvania (Richmond, 1952; Bier, 1985), and southeastern Maryland (Harris and Lyons, 1968). Populations in the tri-state area of southwestern North Carolina, northwestern South Carolina, and northeastern Georgia are disjunct from the main stem of the range (Petranka, 1998). Disjunct populations have also been found in extreme southern Indiana (Madej, 1998). In Virginia, they are known only from the extreme southwestern part of the state in the Appalachian Plateau and Ridge and Valley physiographic provinces (Mitchell and Reay, 1999). Green salamanders are found in the Cumberland Mountains, Cumberland Plateau, and Eastern Highland Rim in Tennessee (Redmond and Scott, 1996). There may be disjunct populations in the Bays Mountains, on Clinch Mountain, in Appalachian Ridge and Valley, and in the Inner Central Basin of Tennessee (Redmond and Scott, 1996). A disjunct population was reported on the eastern slope of Mount LeConte in the Great Smoky Mountains National Park (Weller, 1931), however, animals have not been located since, so it is probably a doubtful record (Redmond and Scott, 1966; Petranka, 1998).
High elevation populations range from 762 m on Clinch Mountain, Virginia (Fowler, 1947), to 915 m on Droop and Backbone mountains in West Virginia (Pauley, 1993b), 1,250 m at Highlands, North Carolina (Gordon and Smith, 1949), 1,265 m on Black Mountain, Kentucky (Barbour, 1953), and to 1,341 m on Cold Mountain, North Carolina (Gordon, 1967).
Systematic studies show there is > 1 form or species of Aneides in the eastern United States. Morescalchi (1975) and Sessions and Kezer (1987) suggest that there are three chromosomally distinct forms. Morescalchi (1975) proposed one form in eastern Tennessee. Sessions and Kezer (1987) described one form in southern Pennsylvania, southern Kentucky, West Virginia, and southwestern North Carolina, and a second form in southern Tennessee and northern Alabama. Jeff Corser and his colleagues (personal communication) recently examined nucleotide sequences from mitochondrial and nuclear genes, as well as ecological, life history, and morphological traits, and found that there are four species-level clades of green salamanders.
2. Historical versus Current Abundance. Weller (1931) reported green salamanders on Mount Le Conte. King (1939) verified the identification of this specimen, but numerous attempts to confirm this locality and the occurrence of green salamanders in the Great Smoky Mountains have failed. Green salamanders declined for some unknown reason in the 1970s in North Carolina (Mitchell et al., 1999). Snyder (1991) discussed several potential reasons for this decline but concluded that the probable cause was that unusually prolonged cold periods may have frozen many hibernating green salamanders in a torpid condition, which prevented them from moving into deeper and safer crevices. Corser (2001) monitored seven historical populations of green salamanders throughout the 1990s on the Blue Ridge Escarpment in northeastern Georgia, northwestern South Carolina, and southwestern North Carolina and found a 98% decline in relative abundance compared to numbers observed in the 1970s. He contributed this sharp decline to habitat loss, overcollecting, epidemic disease, and climate changes.
Barbour (1971) stated that green salamanders reached tremendous population numbers in the 1930s under bark of the millions of dead chestnut trees in eastern Kentucky. Most records of green salamanders beneath bark of downed trees are from the 1920s–'50s, before the original forests were cut (C.H. Pope, 1928; Welter and Barbour, 1940; Fowler, 1947; Gordon, 1952; Barbour, 1953). Petranka (1998) concluded that large, thick slabs of bark on large old-growth logs probably provided more favorable microhabitats for foraging and nesting than the smaller logs found in secondary forests today.
3. Life History Features.
A. Breeding. Reproduction is terrestrial.
i. Breeding migrations. Migrations have been reported from hibernation crevices to outlying rock outcrops during the breeding period (Gordon, 1952). Dispersal of adults as well as juveniles occurs during prehibernation periods (Gordon, 1952; Canterbury, 1991). In the southern Appalachians, Gordon (1952) reported that mating occurs in late May to early June. Snyder (1971) and Cupp (1971, 1991) observed breeding activity in autumn and spring. Cupp (1971) observed courtship and spermatophore deposition on 17 October 1970 in Kentucky. In West Virginia, Brooks (1948a) reported a courting pair on a cliff face between midnight and 0100 h on 13 June 1941. Canterbury and Pauley (1994) determined that mating occurs in late May to early June and possibly in September–October in West Virginia. Dates of egg deposition vary from late May to early July in North Carolina (Gordon, 1952; Eaton and Eaton, 1956; Snyder, 1971); mid July in Kentucky (Cupp, 1991); the third week of July in Mississippi (Woods, 1969); and the first 2 wk of June in West Virginia (Canterbury and Pauley, 1994).
ii. Breeding habitat. Breeding occurs in crevices or rock ledges of emergent rocks, rock outcrops, and rock cliffs in mesophytic forests. Cupp (1971) observed the courtship ritual and subsequent mating of a pair of green salamanders in a crevice of a sandstone rock outcrop in Kentucky. Brooks (1948a) reported watching a courting pair on a cliff face in West Virginia. Gordon (1952) reported that he found single pairs of salamanders in a crevice prior to egg deposition, but he did not observe courtship. Snyder (1971) observed courtship in late May, presumably in a rock crevice because green salamander nests have only been found in rock crevices in the southern Appalachians.
i. Egg deposition sites. Females attend clusters of unpigmented eggs that are held together and attached to the roof of a crevice by strands of mucus. Green and Pauley (1987) reported that several clusters of eggs were observed in central West Virginia on 4 July 1976.
ii. Clutch size. Number of eggs/clutch ranges from 10–30 in North Carolina (Gordon, 1952); 14–20 in Kentucky (Cupp, 1991); 12–27 (Canterbury and Pauley, 1994); and 20–32 (Lee and Norden, 1973) in West Virginia.
C. Direct Development. Females brood. Incubation period of eggs is 84–91 d in North Carolina (Gordon, 1952), 73 d in Kentucky (Cupp, 1991), 82 d in Mississippi (Woods, 1969), and 82–90 d in West Virginia (Canterbury and Pauley, 1994). Norden and Groves (1974) found a female attending newly hatched young on 4 September 1972 in northern West Virginia. Females produce eggs on a biennial cycle (Snyder, 1991; Canterbury and Pauley, 1994).
D. Juvenile Habitat. Juveniles remain in the same habitat as adults. Walker and Goodpaster (1941) observed two groups of hatchlings, each with an attending female, on 30 September 1939 in Ohio. Post-hatching juveniles remain with the female for about 1 mo and then move upward on rock faces toward moss covered ledges and crevices. Juveniles move about more on rock outcrops than do adults (Canterbury, 1991). Gordon (1952) found that after a brooding period of a few months, juveniles leave the nests and move to cracks and crevices. Cupp (1991) observed that dispersing hatchlings and juveniles were found occasionally in places (interfaces between rock cliffs and tree limbs and on more moist rock faces and crevices) where adults usually do not occur.
E. Adult Habitat. Green salamanders have been found in caves (Cope and Packard, 1881), under bark on logs (C.H. Pope, 1928), on cliffs and rock faces (Petranka, 1998) and under logs in forests (T.K.P., personal observation). Bishop (1928) considered green salamanders to be a weak arboreal species. Green salamanders are most commonly encountered in the crevices of emergent rocks, on rock outcrops, and on rock cliffs in forests. Primarily, such rocks do not have running water but are usually in cool, well-shaded, high humidity forests. Occasionally, green salamanders are found on dry rock outcrops (Pauley, 1993b; Waldron et al., 2000). Rock types include sandstone, limestone, dolomite, granite, and quartzite. Type of rock may be less important than crevice size and moisture (Gordon and Smith, 1949).
F. Home Range Size. Home range size has not been determined for green salamanders, but several studies have examined linear movement patterns. In an experiment on the movement of displaced green salamanders, Gordon (1961) found evidence for homing. However, most green salamander movements involve leaving crevices to forage for food and to disperse during the spring and fall. Gordon (1952) found that most adults he followed in a study at Highlands, North Carolina, moved < 3.7 m from the point where he originally captured them. He found two males (of 26 marked) that moved 76.2 m and 91.4 m, and one immature that moved 106.7 m. Most movements were the result of a prehibernation dispersal period that extended from late October to mid December. Canterbury (1991) found that juveniles move more than adults. In central West Virginia, both sexes and all age classes move during the fall dispersal, with some movement in August–September, but most dispersal occurs in October (Canterbury, 1991). Distance moved on single rock outcrops ranged from 3.4–15.8 m (n = 15). Distances moved between rock outcrops ranged from 2.6 m for one female, 16.8–46.3 m for three males, and 6.4–49.4 m for five subadults. Waldron (2000) found in northern West Virginia that the mean linear distance that females travel is 1.86 m, males 3.18 m, and juveniles 3.34 m. Movement only occurred between crevices on a single rock outcrop and not between rock outcrops. Woods (1969) observed that subadults in Mississippi move ≤ 31 m. Green salamanders have been observed crossing roads (Williams and Gordon, 1961; Cupp, 1991).
G. Territories. Males, but not females and subadults, are territorial and aggressively defend their crevices against other males (Cupp, 1980; Canterbury and Pauley, 1991). Gravid females probably mate with males in optimal crevices, and females either use these crevices as nesting sites or move to other favorable crevices (Cupp, 1991). Cupp (1980) observed that resident males won 95.6% of all encounters, and he concluded that size was not a significant factor in territorial defense.
H. Aestivation/Avoiding Dessication. Green salamanders become less active and tend to move deeper in rock crevices during high temperatures and dry conditions of July–August in the lower elevations in West Virginia (Pauley, 1993b). In central West Virginia, Canterbury (1991) found that green salamanders are less active in June–August than in September–October. In higher elevations in northern West Virginia, Waldron (2000) found green salamanders are the most active in June, with little activity from the first week in July to the following May. Snyder (1991) examined several potential causes for the decline of the Blue Ridge populations of green salamanders. While he did not believe drought was the major reason for the declines, he did suggest that the drying effect of droughts could eliminate safe refuges.
I. Seasonal Migrations. Seasonal migrations of green salamanders involve pre-hibernation and post-hibernation dispersals. Gordon (1952) reported that salamanders not observed during the summer on his study sites in North Carolina appeared in October just prior to hibernation. He considered this to be a pre-hibernation aggregation. He also noted a post-hibernation dispersal in late April to early May. By late May to early June, salamanders had moved into crevices. In southeastern Kentucky, Cupp (1991) recorded the major dispersal and aggregation period to be from early November to mid December (pre-hibernation period). Cupp found the post-hibernation dispersal period extended from mid March to late April. In central West Virginia males, females, and juveniles disperse from August–September and into October (Canterbury, 1991).
J. Torpor (Hibernation). Hibernation probably extends from mid December to early March (Gordon, 1952; Canterbury, 1991; Cupp, 1991). Hibernation occurs in deep interconnecting crevices (Gordon, 1952). Gordon (1952) was only able to locate four individuals in deep anastomosing crevices from November–April in North Carolina. There are some reported occurrences during the winter. In central West Virginia, Canterbury (1991) found specimens at the mouths of crevices in November (n = 2), December (n = 9), and March (n = 7). In the lower elevations of the western section of the state, he found individuals at the mouths of crevices in January (n = 1), February (n = 2), and March (n = 2).
K. Interspecific Associations/Exclusions. Cliff-dwelling plethodontid salamanders display a stratification hierarchy (Baltar, 1983; Cliburn and Porter, 1987; Waldron, 2000). Baltar (1983) found that green salamanders occupied the highest crevices on rock faces; northern zigzag salamanders (Plethodon dorsalis) and northern slimy salamanders (P. glutinosus) occupied lower crevices. Waldron (2000) observed green salamanders more frequently on high areas of rock faces than either northern slimy salamanders or Allegheny Mountain dusky salamanders (Desmognathus ochrophaeus). Because green salamanders have a greater climbing ability than northern slimy salamanders (Cliburn and Porter, 1986; Canterbury, 1991) and Allegheny Mountain dusky salamanders (Canterbury, 1991), they may avoid competition with these two sympatric species by moving to upper crevices on rock faces. Canterbury and Pauley (1991) observed Cumberland Plateau salamanders (P. kentucki) in higher crevices on rock faces than northern slimy salamanders and concluded that Cumberland Plateau salamanders are probably keener competitors with green salamanders than are northern slimy salamanders.
Laboratory studies have shown that interspecific associations exist between green salamanders and Cumberland Plateau salamanders, Allegheny Mountain dusky salamanders, and Wehrle's salamanders (P. wehrlei; Cupp, 1980; Canterbury and Pauley, 1991). Canterbury and Pauley (1991) observed aggressive behaviors between male green salamanders, Cumberland Plateau salamanders, and northern slimy salamanders.
L. Age/Size at Reproductive Maturity. Both sexes of green salamanders become sexually mature at about 45 mm in Ohio (Juterbock, 1989). In central West Virginia, both sexes probably become sexually mature during the spring–summer of their third year (Canterbury, 1991).
M. Longevity. Snider and Bowler (1992) report a life span of 3.4 mo for a captive specimen. Since sexual maturity is not reached in both sexes until their third year (Canterbury, 1991), they probably live much longer than 3 yr. Corser (2001) reported that Castanet (unpublished data) found that green salamanders may live 10 yr or longer.
N. Feeding Behavior. As with most salamanders, green salamanders are opportunistic feeders. Gordon (1952) found that prey items included snails, slugs, spiders, and small insects. More specific food items include coleopterans, dipterans, and hymenopterans (Lee and Norden, 1973; Canterbury and Pauley, 1990). All age classes of green salamanders prey on the same items, but hatchlings consume more mites than other invertebrates (Canterbury and Pauley, 1990).
O. Predators. Predators include ring-necked snakes (Diadophis punctatus) and common garter snakes (Thamnophis sirtalis; T.K.P., personal observations) and probably other species of snakes. Juveniles could be prey items of adult Allegheny Mountain dusky salamanders in areas where Allegheny Mountain dusky salamanders inhabit crevices in rock faces.
P. Anti-Predator Mechanisms. Green salamanders avoid most predators through their nocturnal activity, but there is some diurnal activity (Gordon, 1952). Green salamanders are cryptically hidden from diurnal predators by their color pattern that resembles the lichen-covered rocks of their habitat (Brandon and Huheey, 1975). Hatchlings become immobile when touched (Netting and Richmond, 1932; Gordon, 1952; Brodie et al., 1974a). When adult green salamanders are touched with a twig, they turn their tail toward the opening of the crevice and undulate it from side to side (Brodie, 1977).
Q. Diseases. Diseases have not been reported.
R. Parasites. Baker (1987) has reported a nematode Batracholandros magnavulvaris.
4. Conservation. Several types of perturbations can negatively impact green salamanders. Obviously, removal of emergent rocks in forests eliminates this species in such areas. Road cuts and other larger corridors adjacent to emergent rocks and outcrops can result in an increase in airflow and greater insolation, thus increasing temperatures and decreasing moisture. Removal of trees that shade rock outcrops also results in greater insolation that ultimately dries nesting and foraging crevices. In clearcuts, Petranka (1998) suggests a buffer zone of 100 m or more around rock outcrops with known green salamander populations. Blue Ridge populations in North Carolina experienced declines in the late 1970s (Snyder, 1991), and there appears to have been some local extinctions in that area (Mitchell et al., 1999). The total range of the green salamander is fragmented into several disjunct populations, and such isolated populations are always at risk of extinction. Over-collecting in some areas may be a threat (Mitchell et al., 1999; Corser, 2001).
Green salamanders are listed as Endangered in Indiana, Ohio, Maryland, and Mississippi, Threatened in Pennsylvania, Protected in Georgia (http://georgiawildlife.dnr.state.ga.us), Rare in North Carolina, and Of Special Concern in South Carolina and West Virginia.
1 Thomas K. Pauley
2 Mark B. Watson
Literature references for Amphibian Declines: The Conservation Status of United States Species, edited by Michael Lannoo, are here.
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