|Scientific Name:||Ambystoma jeffersonianum (Green, 1827)|
Salamandra jeffersoniana Green, 1827
|Taxonomic Source(s):||Frost, D.R. 2014. Amphibian Species of the World: an Online Reference. Version 6 (27 January 2014). New York, USA. Available at: http://research.amnh.org/herpetology/amphibia/index.html. (Accessed: 27 January 2014).|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||IUCN SSC Amphibian Specialist Group|
|Facilitator/Compiler(s):||Green, C., Sharp, D. & Garcia Moreno, J.|
Listed as Least Concern in view of the large extent of occurrence, large number of sub-populations and locations, and probable large population size.
|Previously published Red List assessments:|
|Range Description:||This species' range was mapped by Conant and Collins (1991) as encompassing an area in the USA from southeastern New York through Pennsylvania and eastern and southern Ohio to southern Indiana, and southward to south-central Kentucky and northern Virginia, with an extensive area of hybridisation with A. laterale northward of this range to eastern Minnesota, northern Wisconsin, Upper Peninsula of Michigan, southern Ontario, southern Quebec, and eastward to Nova Scotia. However, for most of this range, karyological and electrophoretic data are unavailable, so the precise range of pure jeffersonianum populations is uncertain (Bogart and Klemens 1997). The core of the range of pure A. jeffersonianum populations likely extends from Pennsylvania southwestward to Kentucky. The jeffersonianum genome is widely distributed in eastern North America but exists primarily in hybrids (Bogart and Klemens 1997). Individuals that have solely the A. jeffersonianum genome occur in many hybridised populations. Although Klemens (1993) mapped distinct ranges for A. jeffersonianum and A. laterale in Connecticut and adjacent regions, he included in the range of each species populations that were dominated by the pertinent genome, including hybrids. Data presented by Bogart and Klemens (1997) indicate that the few populations in New England and New York represented by only the A. jeffersonianum genome had sample sizes of only 1-3 individuals, so these actually might have been hybrid populations. Phillips (1991) extended the range of A. jeffersonianum into east central Illinois, based on one juvenile raised from a larva, but since only one specimen was examined (and he did not indicate what identification criteria were used), it is unclear whether or not the population represents pure A. jeffersonianum or a hybrid population. Phillips et al. (1999) indicated the occurrence of both pure A. jeffersonianum and hybridised A. jeffersonianum ("A. platineum") in east central Illinois, and they stated that the hybrids use A. texanum sperm to activate egg development. In northern New Jersey, Nyman et al. (1988) found that triploid hybrids apparently occur wherever A. jeffersonianum is found. In Indiana and Ohio, jeffersonianum genomes exist in hybridised individuals that also contain A. texanum and/or A. tigrinum genomes (Morris 1985, Morris and Brandon 1984, Selander et al. 1993, Selander 1994). The estimated extent of occurrence (EOO) is 470,000 km2.|
Native:Canada (Ontario); United States (Connecticut, Illinois, Indiana, Kentucky, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Vermont, Virginia, West Virginia)
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Estimation of A. jeffersonianum population size is difficult due to the presence of morphologically similar unisexuals which share their habitat. For this reason, total adult population size is unknown but surely is greater than 10,000 for unhybridized populations. In an extensive survey of New England and New York, Bogart and Klemens (1997) did not find any "sizeable" populations. The only populations represented by only the jeffersonianum genome were a few from which only 1-3 specimens were obtained; these might have yielded hybrid individuals if they had been adequately sampled. In Kentucky, where most populations might (but not certainly) represent pure A. jeffersonianum, the species appears to be uncommon, based on the poorly known distribution (Barbour 1971). Similarly, in West Virginia, another area likely represented by pure populations (though this is uncertain), the species is believed to occur state-wide but has been documented only from a minority (14) of the state's counties (Green and Pauley 1987), suggesting that A. jeffersonianum is uncommon there. Following surveys in 2003 and 2004, it was discovered that the majority of historical sites surveyed in 1990 and 1991 no longer supported populations of either A. jeffersonianum or unisexuals. Furthermore, at some sites where both A. jeffersonianum and unisexuals did still exist in 2003-04, there was a notable reduction in the number of egg masses compared to numbers found in the earlier surveys (COSEWIC 2010).|
|Current Population Trend:||Stable|
|Habitat and Ecology:||It hides in rodent burrows and beneath leaf-litter, logs, rocks and other surface objects. It also hibernates underground or in rotting logs. In some areas it can be found in caves in (e.g. West Virginia) (Green and Pauley 1987). Eggs are attached to sticks and plant stems in ponds and pools with adjacent deciduous or mixed upland forest. Presence of fishes and newts reduces reproductive success. It is not found in floodplains, swamps or marshes in New Jersey (Nyman et al. 1988). In central Pennsylvania, embryonic mortality was high in ponds below pH 4.5, though this was affected by the availability of other larval amphibians as prey (Sadinski and Dunson 1992). Courtship and egg deposition, which occurs in early spring, may occur under the ice of vernal pools. Females deposit several egg masses on sticks or emergent vegetation. The duration of egg and larval development is variable and temperature-dependent. Carnivorous larvae normally transform in July or early August and leave the pond (COSEWIC 2010).|
|Use and Trade:||There are no records of this species being utilized.|
|Major Threat(s):||It is vulnerable to detrimental alteration of vernal pool breeding sites, especially as a result of residential development. Threats to local populations probably include intensive timber harvesting practices that reduce canopy closure, understory vegetation, uncompacted forest litter, or coarse woody debris (moderately to well-decayed) in areas surrounding breeding sites (deMaynadier and Hunter 1999). Some local populations incur heavy road mortality during migrations to and from breeding sites (Klemens 1993). Increased acid deposition is a potential threat.|
Needed conservation measures include protection of seasonal ponds and adjacent wooded areas up to at least 200-250 m asl from the ponds. Also, regulatory agencies should attempt to minimize forest fragmentation through habitat protection and management.
Conservation goals and better taxonomic and population status information need to be developed with respect to pure and hybridized populations.
|Citation:||IUCN SSC Amphibian Specialist Group. 2015. Ambystoma jeffersonianum. The IUCN Red List of Threatened Species 2015: e.T59059A56458965.Downloaded on 24 September 2017.|
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