167.

Harting’s Vole

Microtus hartingi

French: Campagnol de Harting / German: Balkan-WihImaus / Spanish: Topillo de Harting

Taxonomy. Microtus (Microtus) hartingi Barrett-Hamilton, 1903, Larissa, Thessaly, Greece.

Microtus hartingi is in subgenus Sumeriomys and guentheri species group. In the past, it was synonymized with socialis or more frequently guentheri . Microtus hartingi and M. guentheri have identical diploid number of 2n = 54 but differ in peculiarities of chromosomal morphology and nucleotide sequences. Subspecific taxonomy is not resolved. Monotypic.

Distribution. S Serbia, Macedonia, SE Bulgaria, Greece (including Lesbos I), and Turkey (W & C Anatolia).

Descriptive notes. Head-body 103-138 mm,tail 22-35 mm; weight 31-76 g. Harting’s Vole is large and chunky, with tail ¢.20% of head-body length. Eyes are large, and ears protrude above pelage. Females have two pairs of pectoral and two pairs of inguinal mammae. There are five plantar tubercles. Fur is soft and dense. Back is light dull buff, grizzled by blackish tips of longer hairs; pelage on flanks is plain buff; and belly is buffy white. Skull is heavy and massive, deep across rostrum and braincase, with slightly convex dorsal profile. Temporal ridges are prominent but do not form sagittal crest. Bullae are of modest size. Incisors are orthodont, and M? lacks postero-lingual loop.

Habitat. Dry open habitats, specifically pastures, grasslands, and fallow lands but also various types of arable land from close to sea level up to elevations of ¢.1500 m.

Food and Feeding. Harting’s Vole feeds mainly on green grasses and herbs. The following plants have been recorded in its diet: hawkweed ( Hieracium, Asteraceae), spring vetch ( Vicia lathyroides, Fabaceae), brome ( Bromus, Poaceae), sulphur cinquefoil ( Potentilla recta, Rosaceae), thyme ( Thymus montanus, Lamiaceae), corn gromwell ( Lithospermum arvense, Boraginaceae), alyssum ( Alyssum, Brassicaceae), jagged chickweed ( Holosteum umbellatum, Caryophyllaceae), pea ( Pisum, Fabaceae), dandelion (7araxacum, Asteraceae), alfalfa ( Medicago, Fabaceae), ribwort plantain ( Plantago lanceolata, Plantaginaceae), whitlow grass ( Draba muralis, Brassicaceae), field pansy ( Viola arvensis, Violaceae), silver hairgrass ( Aira capillaris, Poaceae), couch grass ( Cynodon dactylon, Poaceae), milkvetch ( Astragalus, Fabaceae), tumbleweed (Sysimbrium, Brassicaceae), henbit deadnettle (Lamum amplexicaule, Lamiaceae), bull thistle ( Cirsium, Asteraceae), campion ( Silene, Caryophyllaceae), and even leaves of Oriental hornbeam ( Carpinus orientalis, Betulaceae). Daily consumption is 15-19 g of dry food, and full stomachs weights are 3-5 g. Expanded tunnels (up to 7 cm in width) serve as caches for storing blades of green grass that are 4-5 cm long. No stores of grain have been reported from burrows of Harting’s Voles. At peak densities, vegetation can be cropped to the soil surface.

Breeding. Breeding of Harting’s Vole is suppressed in July-September. Gestation lasts 21-23 days in Bulgaria and 22-24 days in Anatolia. Due to postpartum estrus, intervals betweenlitters are 20-60 days. In one breeding season, each female can have up to seven litters and 42 offspring. Numbers of embryos are 2-10/female (mean 5-6). Mean litter sizes in captivity are 4-7-5 young. Young are born naked, deaf, and blind and weigh 2-8-4-4 g. Eyes and ears open at 12-13 days old, and young are weaned at 21-24 days old. Females mature at 35 days old.

Activity patterns. Harting’s Voles are active throughout the year and at any time of the day . They dig burrows that range from short and simple to long and complex. Burrows are frequently in shadows of bushes and trees. Burrow systems are 20-45 cm below the ground’s surface and can be as deep as 80 cm. They have 3-50 entrances and extend 3 m* to more than 150 m®. Entrances are 20-100 cm apart and 4-5 cm in diameter. Complex burrow systems are constructed over time in disturbed habitats (e.g. regularly plowed fields with simple structure). Each burrow system has at least one nest chamber that is located at the deepest point. Complex burrow systems have three nest chambers or more. Total length of tunnels is c.10 m, sometimes more. Nest chambers are 10-18 cm in diameter and 8-14 cm deep, and they are lined with dry grass. Heaps of excavated soil in front of entrances can be up to 20 cm high.

Movements, Home range and Social organization. Social unit of Harting’s Vole is a family group, consisting of a breeding pair with young from 1-2 litters. Breeding starts after pairs are formed. At high densities, Harting’s Voles frequently stand erect on hindlegs to scan surroundings while emitting whistles.

Status and Conservation. Not assessed on The IUCN Red List as a separate species. Harting’s Vole is common with no major threats;it thrives in a variety of habitat types, both natural and man-made; and it is even a pest to agriculture.

Bibliography. Chassovnikarova et al. (2008), Colak et al. (1998), Krystufek & Vohralik (2005), Krystufek, Buzan et al. (2009), Ondrias (1965), Thanou et al. (2012), Yigit & Colak (2002), Zorenko (2013).