153.

Common Pine Vole

Microtus subterraneus

French: Campagnol souterrain / German: Kurzohrmaus / Spanish: Topillo europeo

Other common names: European Pine Vole

Taxonomy. Arvicola subterraneus de SélysLongchamps, 1836, Waremme, Liege, Belgium.

Microtus subterraneus is placed in subgenus Terricola and subterraneus species group. Taxonomic arrangement of subterraneus species group has a turbulent history and still does not achieve general consensus. Low interspecific genetic divergences and high intraspecific divergences in this group make species’ delimitation tentative. On one hand, M. subterraneus might be paraphyletic with respect to major: and daghestanicus . In contrast, the two major phylogenetic lineages of M. subterraneus suggest cryptic taxonomic diversity with two putative species: European subterraneus and Asiatic fingeri. In the past, M. subterraneus was been classified in genus Pitymys . More than 30 subspecies were named in the past, but there is no consensus over their validity.

Distribution. W, C & E Europe, from France E to W European Russia and SE to N Greece and European Turkey, and W & N Anatolia, with an outlying record from Bitlis Province (SE Turkey).

Descriptive notes. Head—body 79-115 mm, tail 20-44 mm; weight 10-26 g. Laboratoryreared Common Pine Voles grew larger than free-living counterparts. The Common Pine Vole is smallto medium-sized, with dwarf eyes and relatively long ears. Tail is 20-36% of head-body length. Females have two pairs of inguinal nipples; pectoral pair is exceptional. Fur is long and soft, yellowish brown to dark brown on back and silver or gray on belly. Tail is indistinctly bicolored, and feet are brown. Skull resembles that of the Caucasian Pine Vole ( M. daghestanicus), but it is less shallow, normally with straight or slightly convex dorsal profile, and relatively shorter rostrum. Molar pattern is as in the Caucasian Pine Vole.

Habitat. Dense vegetation for shelter and deep, light, and humid soil for digging from sea level to elevations of ¢.2335 m. The Common Pine Vole occupies marshes, closecanopy woodland, and gardens. It is capable of unearthing underground tunnels in soil and among rocks.

Food and Feeding. In western Carpathian Mountains, diets of Common Pine Voles are 15-5% sedges and grasses, 53-5% other green plants, 10% mosses, 11:5% various fruits, and 2-5% mushrooms. The most important dietary plants include common dandelion ( Taraxacum officinale), alpine coltsfoot ( Homogyne alpina), hawkweed (Hieractum), lawndaisy ( Bellis perennis), melancholy thistle ( Cirsium heterophyllum), and common yarrow ( Achillea millefolium), all Asteraceae; lady’s mantle ( Alchemilla) and trailing arbutus ( Geum reptans), both Rosaceae; yellow marsh marigold ( Caltha palustris, Ranunculaceae); harebells ( Campanula barbata and C. scheuchzeri, Campanulaceae); hairy chervil ( Chaerophyllum hirsutum, Apiaceae); chiltern gentian ( Gentianella germanica) and willow gentian ( Gentiana asclepiadea), both Gentianaceae; mountain wood sorrel ( Oxalis acetosella, Oxalidaceae); rattle ( Rhinanthus aristatus, Orobanchaceae); bird’s-foot trefoil ( Lotus corniculatus) and various species of clover (Tri Jolium badium and T. pratense, Fabaceae); stinging nettle ( Urtica dioica, Urticaceae), and several species of gypsyweed ( Veronica beccabunga, V. fruticans, and V. officinalis, all Plantaginaceae).

Breeding. Breeding season of the Common Pine Vole occurs throughout the year but is frequently interrupted in winter. Gestation is 21 days. Captive females had postpartum estrus and annually delivered ten litters. Mean interpartum time is 24-5 days (range 20-26 days). Numbers of embryos are 1-5/female (most often 2-3). Mean number varies geographically between 2-3 in western Carpathians and 2-7 in eastern Poland. Mean number also varies seasonally, and litters are largest in spring and early summer. Young are born blind and helpless, with very short (0-5 mm) dorsal hair and 2-3 mm long whiskers. Eyes open at 11-14 days old. Young weigh 1-9 g at birth and c.11 g at c.4 months. They are weaned at 15-17 days old. Males are sexually mature at 2-3 months old and females at 90 days. Young can reproduce in their first year.

Activity patterns. Common Pine Voles are polyphasic and nocturnal. They have 12-14 periods of activity during the day, each lasting for 20-40 minutes. Young individuals are more active (23 active periods/ day) than pregnant or lactating females. Common Pine Voles move around in underground galleries. They dig their own galleries or take over mole tunnels. Unearthed soil is pushed to the ground’s surface, but entrances are only seldom sealed with heaps. Where dense vegetation provides good shelter, Common Pine Voles are active aboveground.

Movements, Home range and Social organization. Female Common Pine Voles occupy exclusive territories (mean 256 m?) that overlap home ranges of one or more males (mean 1025 m?*). Common Pine Voles live in groups of 6-11 individuals that occupy several nests. Co-nesting between males and females is not frequent. Mating Is promiscuous.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Overall distribution of the Common Pine Vole is nearly 3,000,000 km? and larger than for any other species in the subgenus Terricola.

Bibliography. Gromov & Erbajeva (1995), Krystufek & Vohralik (2005), Niethammer (1982d), Salvioni (1988, 1995a), Shenbrot & Krasnov (2005), Spitzenberger (2001c).