Marbled salamanders are one of two species of mole (Ambystomid) salamanders that have been detected in Rhode Island. Mole salamanders are fossorial, therefore they are rarely observed above ground, with the exception of their brief breeding season. A much more common congener, spotted salamander (Ambystoma maculatum), is widespread and found throughout the state. In contrast, marbled salamanders have a relatively limited distribution; they are primarily restricted to western and southern portions of the state.
The marbled salamander is a peculiar member of the amphibian community in Rhode Island. It is the only species that breeds in the fall, whereas, all other species breed in the spring or summer (Klemens 1993). Based on our fieldwork in Rhode Island, marbled salamanders tend to prefer large, undisturbed tracts of forest, although we also detected this species in a large forested tract of land in Warwick (Paton and Egan 2001). Klemens (1993) also found marbled salamanders were more prevalent in rural areas of Connecticut, however, he also collected some individuals in suburban and urban areas.

• Marbled salamanders are the only black and white salamander in Rhode Island.
• Adults are moderately sized, as their total length is about 7-11 cm [3-4"] (see specific details below).
• Their body is black, with white or light gray crossbands on the head, back, and tail.
• Dorsal crossband colorations differs between genders, males have silvery white crossbands, whereas those of females are silvery gray.
• Gender is best determined just prior to breeding (August), when adult males have swollen cloacal glands, which have a squared off appearance. In contrast, the cloaca of females tends to be more rounded. After males deposit spermatophores, the cloacal protuberance of males subsides and is less obvious.
• There are 11-13 costal grooves.
• The venter is uniformly bluish-black or brownish-black.
• There is much individual pattern variation. B. Shoop and T. Doty (pers. comm.) have been photographing marbled salamanders for 10 years to keep track of individuals at a breeding pond in western Rhode Island.
• Partially albinistic larvae have been reported once in Tiverton, Rhode Island (Deegan et al. 1998), which possessed integumentary xanthophores and orbital melanophores.
• Hatchlings are blackish and rather drab and have pond-type morphology with bushy gills and dorsal fins that extend almost to the front limbs (Petranka 1998a).
• Marbled salamander larvae have a larger head, a higher dorsal tail fin, and more pointed tail than those of spotted salamanders.

Marbled salamanders are one of the primary species investigated at Rainbow Bay, South Carolina, where Semlitsch et al. (1996) have been studied amphibian community structure for over 16 years. The study documented tremendous interannual variation in population sizes and productivity. The number of breeding females captured annually ranged from none to over 600, whereas the number of metamorphs emigrating from ponds ranged from none (4 out of 16 years) to almost 9000.

In Rhode Island, marbled salamanders typically breed in ponds found in mixed deciduous or coniferous forest stands (e.g., both white pine (Pinus strobus) and pitch pine (Pinus rigida). This species appears to prefer dry, friable soils including sand and gravel deposits, as well as rocky slopes, although they are sometimes found in low-lying swampy areas (Klemens 1993). Marbled salamanders are thought to inhabit somewhat drier areas than other species of Ambystoma (DeGraaf and Yamasaki 2001); however, in Ohio they are usually found in swampy forests (Ptingsten and Downs 1989). Breeding occurs in temporary wetlands, including wooded swamps, kettle ponds, and along river floodplains. In Rhode Island, such sites generally contain red maple (Acer rubrum) and pin oak (Quercus palustris) (Raithel unpubl. data).

In addition to needing extensive forests, the presence of sphagnum moss in the pond basin is possibly another important habitat characteristic useful for detecting potential breeding ponds. Egg masses are generally deposited under sphagnum in dried-up pools and guarded by females until ponds until water levels inundate the eggs (T. Doty, pers. comm.).

In Rhode Island, adults start to immigrate to breeding ponds around 1 August. Adults are generally only active on rainy nights. The majority of adults are at breeding ponds by 26 August, with some stragglers arriving as late as 10 September (Paton and Crouch In press). Males often court females before arriving at the nesting sites and males often arrive at the ponds from a few days to more than 2 weeks before females (Petranka 1998a). Adults in northern populations tend to breed earlier than those in southern populations (Petranka 1998a). Klemens (1993) documented peak breeding in Connecticut from mid-September to early October. Males tend to leave the ponds in early October, while females remain in ponds for several weeks to brood eggs. Females generally do not leave ponds until late October or early November in Rhode Island (Paton and Crouch In press).

Metamorphs emigrate from breeding pond between mid-June and mid-July (Paton and Crouch In press).

Marbled salamanders are listed as a threatened species in Massachusetts, and Lazell (1979) attributed their drastic declines in Massachusetts to a combination of factors including pollution, habitat fragmentation, and acid rain. However, Klemens (1993) mentioned that Massachusetts is the northern limits of their range, and declines in the region may be due a to range retraction. In the southeastern United States, the greatest environmental threat to this species is loss of bottomland hardwoods and associated vernal pool habitats (Petranka 1998a). Thousands of local populations of marbled salamanders have already been eliminated by habitat loss, and more will be lost in the future. In New England, urban sprawl has eliminated marbled salamanders from large portions of their range on western Long Island and lower Westchester County, and they probably will become scarcer on eastern Long Island and in the Hudson Valley as urbanization continues (Klemens 1993).

Pechman et al. (1991) found that marbled salamander populations act as metapopulations, therefore some contact between sites must be maintained for population persistence. Isolation of populations is invariably the precursor of extirpation. Taylor and Scott (1997) summarized existing demographic data for marbled salamanders and suggested that at least 70% adult survivorship, or an immigration event from adjacent populations, was necessary for population persistence. High adult survivorship is necessary because recruitment is so sporadic

In Rhode Island, marbled salamander populations appear to be relatively secure, at least for the short term (Klemens 1993). However, if suburbanization of the western sections of the state continues, populations could easily be extirpated. Raithel (unpubl. data) observed high rates of adult and juvenile mortality caused by auto traffic, which must negatively affect populations. Other factors affecting marbled salamanders, including increased environmental acidity and pollution, may impact populations (Lazell 1979), but habitat loss and fragmentation is probably the greatest threat to marbled salamanders in Rhode Island. At the Alton Jones campus, the marbled salamander population remains relatively stable at one breeding pond in a relatively unfragmented, mixed deciduous/coniferous forest over 1000 acres in size (T. Doty and B. Shoop, pers. comm.). This same area has been aerial sprayed twice with Carbaryl (Sevin) (Doty 1978), often gets fairly acidic rainfall, and has had outbreaks of the bacteria Aeromonas hydrophila, which can negatively impact wood frog productivity (Nyman 1985).