19.

Long-clawed Mole Vole

Prometheomys schaposchnikowi

French: Lemming prométhée / German: Prometheus-Maus / Spanish: Topillo topo de unas largas

Other common names: Promethean Vole

Taxonomy. Prometheomys schaposchnikow: Satunin, 1901, “Kaukasus.” Restricted by S. I. Ognev in 1947 to Gudaur, south of Krestovyi Pass, Dusheti District, Georgia.

Prometheomys schaposchnikow:, the only member of the genus Prometheomys, has many primitive characteristics and is phylogenetically isolated among voles and lemmings. The genus might be basal in Arvicolinae. The specific name is frequently misspelled as schaposchnikovi. Monotypic.

Distribution. Endemic to Ciscaucasian Russia (Adygea, Karachay-Cherkessia, Kabardino-Balkaria, and North Ossetia), Georgia, and NE Turkey.

Descriptive notes. Head—body 126-165 mm,tail 36-58 mm; weight 59-5-87-8 g. Males are slightly larger than females. The Long-clawed Mole Vole is medium-sized, with shorttail averaging one-third of head-body length. Tail is thick, wide at base and tapering gradually toward tip. Eyes are very small (2-1 mm in diameter), but ears are long and protrude from pelage. There is no pad on rhinarium. Females have eight nipples, two pairs of pectoral and two pairs of inguinal ones. Front claws are 6-2-7-2 mm long and slender; those on hindfeet are shorter than 4 mm. There are five plantar pads. Fur is silky and up to 6 mm long. Tail is densely clad, with hairs and well penciled. Pelageis rusty brown, with pinkish shade on belly.Juveniles are grayer than adults. Feet are dark brown; tail is uniformly brown, but tip is frequently white. Black individuals are fairly common. Skull is robust and squarish. Sagittal remains open throughout life, which is not common for arvicolines. Interparietal bone is very small. Supraorbital ridges fuse to produce medial crest. Dorsal side is bowed in lateral profile. Occipital region is vertical rather than inclined forward—surprising for a burrower. Mandible shows no peculiarities. Upper incisors are orthodont, with shallow longitudinal furrows on front surfaces. Molars have two roots each. Crowns are low, and reentrant angles lack cementum. Enamel pattern is simple, with broadly confluent alternating triangles.

Habitat. Mesic meadows in alpine and subalpine zones at elevations of 1500-2800 m where snow cover persists for more than 200 days/year. Soil is light and moist. Longclawed Mole Voles occupy tall-grass meadows and short-grass pastures, forest clearings, and arable land, but they avoid steep slopes and rocky areas. Dominant plants in meadows are quackgrass ( Elymus repens) and Volga fescue ( Festuca valesiaca), both Poaceae; milkvetch ( Astragalus microcephalus, Fabaceae); globe thistle ( Echinops ritro, Asteraceae); field eryngo ( Eryngium campestre, Apiaceae); butterwort ( Ranunculus elegans, Ranunculaceae); sorrel ( Rumex, Polygonaceae); and nettle ( Urtica, Urticaceae).

Food and Feeding. The L.ong-clawed Mole Vole is strictly herbivorous and feeds aboveand belowground. Feeding bouts out of burrows last 5-20 minutes. Roots, tubers, and bulbs are stored for winter. Caches contain up to 3-5 kg of plant material that is mixed with earth to stay fresh.

Breeding. Breeding season occurs from late May to early August. Females are reproductively active at weights above 47 g and have two litters annually. Females have 3-6 embryos (mean 3-8). Itis not known if females reproduce during their first year. Longclawed Mole Voles might survive two winters.

Activity patterns..ong-clawed Mole Voles are active at any time of day throughout the year. Digging activity starts 0-5-1 hour after the sun begins to shine in an area with already warmed soil. Activity peaks between 12:00 h and 14:00 h and gradual decreases afterward. Individuals are less nocturnal during winter. The Long-clawed Mole Vole is fossorial, digging with long claws on powerful front limbs. Small colonies excavate extensive underground systems of main radial burrows from which numerous short tunnels branch toward the ground’s surface. Unearthed soil is pushed on the surface into small mounds that usually seal entrances. Mounds tend to be larger in central part of the burrow system than on the periphery. Up to 10% of the ground’s surface can be covered by heaps of excavated soil. A nest chamber (22-45 cm in diameter) is central to the burrow system, and 3-14 tunnels radiate from it. Numbers of tunnels are larger (9-12) in old burrow systems. Tunnels are up to 7-8 cm wide when lying not more than 7-15 cm below the surface but narrowed to 2:2—4 cm around the nest, presumably preventing predators from entering. Nest chamberis usually 0-5-1-2 m deep and is lined with dry grass. The initial 25-30 cm of tunnels radiating from the nest are expanded and transformed to caches. Caches are occasionally transformed into latrines; when filled by excrement, latrines are plugged by soil. Winter nests (outer diameter up to 30 cm, inner diameter 8-10 cm) are under snow.

Movements, Home range and Social organization. Social unit consists of a reproductive pair and its young, which occupy same burrow. Peripheral tunnels can connect galleries of different families. Group of families (colony) occupy 200-500 m=.

Status and Conservation. Classified as Near Threatened on The IUCN Red List. Distribution of the Long-clawed Mole Vole is small (c.5000 km?*) and fragmented into three main groups of populations. Its narrow habitat requirements restrict its distribution above tree line. Although local densities can be high (150-200 ind/ha), colonies are frequently small and widely scattered. The Long-clawed Mole Vole can suffer increased mortality from repeated snow melting and freezing in March-April.

Bibliography. Bukhnikashvili & Krystufek (2008), Gromov & Erbajeva (1995), Krystufek & Vohralik (2005), Ognev (1947), Shenbrot & Krasnov (2005), Shidlovsky (1976), Spitzenberger & Steiner (1964), Vinogradov (1926), Vorontsov (1966).