This species is restricted to north-east Anatolia (the cities of Ordu Giresun, Rize, Trabzon, Artvin, Kars, Bayburt, and Gumushane), Turkey, and the western spurs of the Trialeti Mountain Ridge, Meskhetian and Lazistanian ridges, Georgia. It is present at altitudes of sea level-1,800m asl.
Habitat and Ecology
It is a habitat specialist, found mainly in beech (Fagus orientalis), coniferous (Abies nordmanniana and Picea orientalis), box forest (Buxus sp.), in Mediterranean shrub forest, mixed forests, the subalpine belt and in alpine meadows. The species tends to avoid large streams and lives mainly in the tributaries of rivers, usually no more than 1-1.5m in width and about 20-30cm in depth in spring. These brooks flow in dense shade and their banks are covered with dense arboreal and herbaceous vegetation (including the large fern Mateuccia strutiopteris). The banks contain a thick layer of leaf and branch litter, dense moss, and grass. It breeds in the streams. In general, this salamander avoids anthropogenically altered landscapes.
It is generally rare (but can be locally common) within suitable habitat. Populations of this species in Georgia display significant fluctuations, and the population in Turkey has probably declined significantly over the past decade. In Karst streams are locally abundant and occur is small "caves" along stream edges.
Habitat destruction is a major threat across the species range. In Georgia, the destruction of forests (tree felling), use of brooks as roads for the transportation of cut trees, and destruction of habitats by cattle are known causes of population declines. In Turkey, only around 12% of suitable forest habitat remains within the species range (Özhatay, Byfield and Atay 2003), and suitable subalpine and alpine meadows are being degraded through road construction and "summer house" tourism in the Eastern Black Sea Mountains (Magnin and Yarar 1997). Additionally, several dams are being constructed on streams used by this species. This species is collected for the pet trade.
In Georgia, the species occurs in two protected areas (Borejomi-Haragauli NP and Kintrish Reserve); three national parks are present within the Turkish range. The species is listed in the Red Data Books of the USSR and Georgia.
Red List Status
Listed as Vulnerable because its Area of Occupancy is less than 2,000 km2, its distribution is severely fragmented and confined to small streams free of fish, and there is continuing decline in the extent and quality of its habitat in Turkey and Georgia. The species is undergoing a rapid reduction across its range at it may also qualify for Vulnerable under A3c upon further investigation.
The taxon Mertensiella caucasica includes two allopatric phylogenetic species (yet to be formally described), reciprocally monophyletic, separated since the Pliocene. Mertensiella sp.1 lives in the basin of the Kura River, Mertensiella sp.2 in the basin of the Black Sea. The validity of the subspecies M. caucasica djabaschvilii is in doubt (S. Kuzmin pers. comm.).
Ugur Kaya, Boris Tuniyev, Natalia Ananjeva, Nikolai Orlov, Theodore Papenfuss, Sergius Kuzmin, David Tarkhnishvili, Sako Tuniyev, Max Sparreboom, Ismail Ugurtas, Steven Anderson 2009. Mertensiella caucasica. The IUCN Red List of Threatened Species 2009: e.T13198A3418986. http://dx.doi.org/10.2305/IUCN.UK.2009.RLTS.T13198A3418986.en .Downloaded on 20 February 2019