Although active throughout the day and night, this vole is most active at dusk (4). It feeds primarily on the stems and leaves of grasses (4). Males defend territories, whereas females do not (4). Breeding typically takes place between April and September, but births may occur throughout the year when conditions are good (4). Between 2 and 7 litters are produced each year, each consisting of 4-6 young. Sexual maturity is reached at 40 days in males, and 28 days in females (4). Most predatory birds and mammals take field voles; indeed this species is a very important component of the diet of many of Britain's birds of prey, so much so that creation of grasslands suitable for field voles has been shown to boost populations of kestrels (Falco tinnunculus) and barn owls (Tyto alba) (5). The maximum lifespan for field voles is 18 months, although very few individuals survive to reach their second autumn (4). When it occurs in high densities, the field vole can be a pest in grasslands, young plantations and crops (4). Although there are few data to show populations sizes of field voles, there is a general belief that populations may have been declining since 1970 (4).

Like all voles, the field vole has a small, stocky body and a blunt, rounded muzzle (5). The fur is greyish-brown on the upperparts, and creamy-grey below. The rounded ears are covered with fur, and the eyes are less obvious than in mice (2).

The field vole is a widespread Palaearctic species, ranging from western Europe eastwards through Russia to Lake Baikal in south-east Siberia. It is present in Great Britain, central and northern parts of the continent (Portugal, Spain, France, Switzerland, Italy, Slovenia, Croatia, Bosnia and Herzegovenia and Serbia), but it is absent from Iceland, Ireland southern Europe (Zima 1999, Shenbrot and Krasnov 2005). The Mediterranean populations may be a separate species, but more taxonomic work is needed to confirm this. It occurs from sea level to 2,100 m in the Alps (Spitzenberger 2002).

This species is believed to be the most numerous of the British mammals; it has a wide albeit patchy distribution throughout Britain. They are not present on the Scilly Isles, Orkney, Shetland or Lundy Island (4). This vole is also widespread throughout central and northern Europe (4).

Habitat and Ecology

Systems

• Terrestrial

Inhabits ungrazed grasslands, with plenty of vegetation cover (4). Main habitats include meadows, the margins of fields, and forestry plantations, but they may also be found in hedgerows, dunes, open moorland and blanket bogs (4).

Animal / parasite / ectoparasite / blood sucker
Amalaraeus penicilliger mustelae sucks the blood of Microtus agrestis

In Great Britain and/or Ireland:
Animal / parasite / endoparasite
fluke of Corrigia vitta endoparasitises pancreas (interlobary canals) of Microtus agrestis

Animal / rests in
Entamoeba muris rests inside large intestine of Microtus agrestis

Animal / parasite / endoparasite
cyst of Frankelia microti endoparasitises brain of Microtus agrestis

Animal / parasite / endoparasite
Giardia microti endoparasitises small intestine of Microtus agrestis

Animal / parasite / endoparasite
schizont of Hepatozoon microti endoparasitises liver of Microtus agrestis
Other: minor host/prey

Animal / parasite / ectoparasite / blood sucker
Hystrichopsylla talpae talpae sucks the blood of Microtus agrestis
Other: minor host/prey

Animal / parasite / ectoparasite
Polyplax serrata ectoparasitises body of Microtus agrestis

Animal / rests in
caecum of Syphacia obvelata rests inside Microtus agrestis

Animal / parasite / endoparasite
Trichomonas muris endoparasitises caecum of Microtus agrestis

Animal / parasite / endoparasite
Trypanosoma microti endoparasitises blood plasma of Microtus agrestis
Other: sole host/prey

Maximum longevity: 4.8 years (captivity) Observations: Voles, in general, are short-lived and show seasonal population crashes, probably due to lack of food. One captive specimen lived 4.8 years (Richard Weigl 2005).

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Species: 11
Species With Barcodes: 1

Not legally protected in the UK. No conservation designations (3).

Population

Population Trend

Major Threats

Overgrazing, reductions in the amount of rough grassland, development, scrub growth and removal of linear features such as hedgerows, all impact negatively on this vole. Furthermore, poisoning by rodenticides is also a threat (4).

Conservation Actions

The precise status of the field vole is not clear at present. Although a common species, it may well have declined, and its importance as a food source for predatory birds makes it more pertinent that its status should be assessed (4). Conservation measures and the maintenance of biodiversity are important, even though this vole is common. The creation of grassy field margins and set-aside areas encourages this species (2), and has the added bonus that birds of prey also benefit (5).