Amphibians of North Carolina

Scientific Name:	Common Name:		Family (Alpha):

Ambystomatidae Members:
Ambystoma mabeei - Mabee's Salamander

Taxonomy

Class: Amphibia

Order: Caudata

Family: Ambystomatidae


Taxonomic Comments: The genus Ambystoma consists of 32 currently recognized species that are found in North America and Mexico. The terrestrial adults have stout bodies and legs, widely spaced eyes, and well-developed costal grooves.
Species Comments:

Identification

Description: Mabee's salamander is a relatively small Ambystoma with a dark brownish gray to black dorsum overlain with light gray or whitish flecks. The light flecks are concentrated on the sides, and the venter is light gray or grayish brown with a few scattered, light flecks. The tail comprises only about 40% of the total length and there are usually 13 costal grooves. Adults vary from about 8-12 cm TL (Petranka 1998). The larvae have bushy gills and broad dorsal fins that extent onto the back. Hatchlings have a single yellow stripe on either side of the body and lack conspicuous mottling on the dorsal and ventral fins. The older larvae are brown to blackish above with two bold, cream-colored stripes along either side of the body. The venter is inconspicuously marked and tends to be flesh-colored. The dorsal fin is moderately developed and becomes heavily mottled with black along the tail as larvae mature. Recently metamorphosed animals are black or dark gray above with little or no light flecking.

Technical Reference: Petranka (1998); Mitchell (2021)

Field Guide Descriptions: Beane et al. (2010)

Online Photos: Google iNaturalist

Observation Methods: Adults are active on the ground surface during the breeding season and can be found beneath surface objects in sandy pinewoods or near cypress-tupelo stands near breeding ponds. The larvae can be collected by dip-netting in leaf litter or other cover during the spring and summer months.

AmphibiaWeb Account

Distribution in North Carolina

Distribution Comments: Mabee's Salamander inhabits Coastal Plain habitats from extreme southeastern Virginia to southern South Carolina. In North Carolina it is most common in the southern half of the Coastal Plain, with only a few documented populations farther north.
Distribution Reference: Beane et al. (2010); Mitchell (2021); Petranka (1998)
County Map: Clicking on a county returns the records for the species in that county.


GBIF Global Distribution

Key Habitat Requirements

Habitat: The adults breed in fish-free habitats and live in the surrounding forests. Local populations are commonly associated with Carolina Bays and Longleaf Pine woodlands and Pond Cypress savannas with embedded depression ponds that are used as breeding sites. A variety of other fish-free habitats may be used, including semipermanent farm ponds, fox-holes filled with water, vernal ponds in river bottomlands, and tupelo-cypress ponds in pine woods. Adults may stay in the vicinity of the pools year-round or may move fairly long distances out into the surrounding woodlands (Petranka 1998). They have been found in both relatively dry sites such as pine forests, as well as wet sites such as small stream swamps that are in the vicinity of fish-free breeding pools (Beane et al. 2010). They presumably live in underground burrows for most of the year where they seek refuge from the hot and dry conditions that often occur during the summer months on the Atlantic Coastal Plain.

In North Carolina A. mabeei is commonly found in the vicinity of fish-free breeding sites such as Carolina Bays and seasonal depression ponds in pine forests. A variety of other fish-free habitats may be used, including borrow pits, swamp forests with seasonal wetlands, and water-filled craters on military bombing ranges.

Biotic Relationships: The larvae are palatable to fish and populations are almost always restricted to habitats that lack predatory fish. This species is an important predator on aquatic invertebrates, and in many ways fulfill the ecological roles of small fishes in permanent ponds. Breeding ponds in the Coastal Plain often support a rich diversity of amphibians, but the ecological interactions of A. mabeei with other amphibians are poorly studied. The larvae are known to share breeding ponds with the Tiger Salamander (A. tigrinum), the Marbled Salamander (A. opacum), the Mole Salamander (A. talpoideum), the Lesser Siren (Siren intermedia), and the Eastern Newt (Notophthalmus viridescens), as well as with as many as ten species of frogs and two other species of salamanders (Mitchell 2021). Both Tiger Salamander larvae and Lesser Sirens feed on the larvae (Hardy 1969b).

See also Habitat Account for Longleaf Pine Woodlands with Isolated Pools

Life History and Autecology

Breeding and Courtship: Many aspects of the breeding biology of this species are poorly documented. The adults migrate to breeding ponds and breed during periods of heavy, warm rains in winter or early spring. Hardy (1969a, b) found eggs between 2 February and 30 March at study sites in southern North Carolina, but noted that breeding can begin as early as mid-January in some years. Courtship behavior has not been described.

Reproductive Mode: After mating, the females attach their eggs singly or in loose strings of 2-6 eggs to vegetation and detritus in ponds. Each female scatters her eggs widely throughout the breeding site. The egg is surrounded by a vitelline membrane and two jelly capsules, and the embryonic period lasts 9-14 days in North Carolina populations (Hardy 1969b).

Aquatic Life History: The larvae feed primarily on zooplankton and other invertebrates, and incorporate larger prey into the diet as they mature. Common prey items include ostracods, cladocerans, copepods, isopods, amphipods, and a variety of insects such as ephemeropterans, dipterans, hemipterans, and odonates (McCoy and Savitzky 2004). On rare occasions, they will feed on anuran larvae. The larvae grow rapidly and begin to transform within a few months after hatching (Petranka 1998). Hardy (1969a) found that larvae in a North Carolina population transformed in early to mid May after 2 months of growth. The smallest transforming larvae were 55-60 mm TL. Mitchell and Hedges (1980) collected five metamorphs in late April and mid-May in Virginia that were 37-46 mm SVL and 60-79 mm TL, while larvae collected from a South Carolina pond on 24 March transformed in 8-12 days at 50 mm TL (Petranka 1998).

Terrestrial Life History: Very little is known about the terrestrial ecology of the juveniles and adults. In some instances, the juveniles may disperse long distances from their natal ponds. Hardy (1969a) collected 91 recently transformed juveniles on 30 May that were over 800 m from the nearest known body of water. Limited evidence indicates that some adults remain in close proximity to breeding ponds, while others disperse widely into the surrounding forests after breeding. Hardy (1969a) found adults throughout most of the year beneath surface cover in or near the dried bottoms of breeding ponds. Other specimens were collected in open fields and adjoining forests during the summer months. He observed large numbers of adults on the ground surface on rainy nights during the breeding season, but was uncertain whether these were migrating to breeding ponds (Petranka 1998). The adults presumably live in underground burrows outside of the breeding season where they seek refuge from the hot, dry conditions that often occur in the Atlantic Coastal Plain during the summer months.

General Ecology

Population Ecology: Like most Ambystoma species, local populations of Mabee's Salamander tend to be organized as metapopulations. A metapopulation is a regional group of local populations that are connected by the occasional movement of individuals between populations. Connectivity between local populations allows for the recolonization of ponds following local extinctions and reduces the chance of a local population going extinct when a population is in decline. Although poorly documented, the maximum size of local pond populations at sites with intact forest buffers is presumably set by density-dependent interactions during the larval stage. In general, crowding of Ambystoma larvae intensifies intra- and interspecific competition for food, and can stunt larval growth, reduce the size at metamorphosis, and reduce overall survival to metamorphosis (Petranka 1998).

Community Ecology: The larvae share breeding ponds with a variety of potential predators and competitors, but very little is known about how interactions with community members affect the yearly output of juveniles from the breeding ponds.

Adverse Environmental Impacts

Habitat Loss: Since European colonization, populations of Mabee's Salamander have experienced significant long-term declines associated with deforestation, urbanization, agricultural and silvicultural activities, and the filling and draining of wetlands. Local populations require both fish-free breeding sites and forested buffers to support the juveniles and adults. Wetlands like those used by this species were largely unprotected during the last century. From the 1950s–1970s the loss of wetlands in the Southeast was greater than in any other region of the country, with a net annual loss of 386,000 ac/yr (Hefner and Brown 1985). In North Carolina approximately 51% of all wetland acreage on the Coastal Plain has been lost. Countless thousands of Carolina bays, pocosins and other depressional wetlands that served as primary breeding sites for Mabee's Salamander and other seasonal-pond breeders have been drained, filled, and converted to agricultural fields or commercial pine plantations (e.g., Bennett and Nelson 1991, Lundine and Trembanis 2021, Richardson 2003, Sharitz and Gibbons 1982). As local pond populations are lost from factors such as deforestation or wetland draining and filling, metapopulation structure can be compromised as the distance between the nearest populations exceeds the dispersal distance of juveniles and adults.

Habitat Fragmentation: Much of the original bottomland hardwoods and Longleaf Pine forests that blanketed the Coastal Plain prior to European colonization has been lost or fragmented as extensive tracts of forest have been converted into a patchwork of agricultural fields, residential homes, urban development, pine plantations, roadways, and isolated hardwood parcels. In some cases small forest tracts may have seasonal ponds that are adequate for the larval stage, but the surrounding forest buffer is too small to support a viable adult population. Even when a forest buffer is intact, local pond populations may be isolated from nearest neighbors due to barriers to dispersal such as roadways or large agricultural fields. Small, isolated populations are vulnerable to local extinction and may ultimately be lost with time.

Limited data suggest that Ambystoma mabeei may be more tolerant of landscape disturbance than other Ambystoma species since it has been found in pine forests and even in open fields. The adults also have been found close to breeding ponds during the non-breeding season, which suggests that populations in some areas may be able to tolerate loss of the surrounding forest buffer to some extent. More detailed information is needed on the terrestrial requirements of this species, and the extent to which potential barriers such as multiple-lane roads, large agricultural fields, and urban development limits the movement of individuals between local breeding sites.

Status in North Carolina

NHP State Rank: S2

Global Rank: G4

Status in North Carolina: T

Environmental Threats: The greatest environmental threats are from the continued loss of depressional wetlands and surrounding forest habitat.

Status Comments: This species has experienced significant long-term declines in North Carolina associated with deforestation, urbanization, agricultural and silvicultural activities, and the filling and draining of seasonal wetlands.

Stewardship: Local populations are best maintained by protecting seasonal and semi-permanent depressional wetlands and the surrounding forests that provide habitats for the juveniles and adults.

Photo Gallery for Ambystoma mabeei - Mabee's Salamander		10 photos are shown.
	Recorded by: Jackie Goodman Robeson Co.	Recorded by: Jackie Goodman Scotland Co.
	Recorded by: Rob Van Epps Robeson Co.	Recorded by: L. Garner Bladen Co.
	Recorded by: E. Corey Bladen Co.	Recorded by: Ed Corey Scotland Co.
	Recorded by: Ed Corey Hoke Co.	Recorded by: Steve Hall Brunswick Co.
	Recorded by: Jim Petranka Scotland Co.	Recorded by: Scott Bolick Scotland Co.

Ambystoma mabeei - Mabee's Salamander

Photo Gallery for Ambystoma mabeei - Mabee's Salamander

10 photos are shown.