510.

Long-tailed Field

Mouse

Apodemus sylvaticus

French: Mulot sylvestre / German: \ Waldmaus / Spanish: Ratén de campo de cola larga Other common names: Small Wood Mouse, Wood Mouse

Taxonomy. Mus sylvaticus Linnaeus, 1758,

Uppsala

, Sweden.

Apodemus sylvaticus was included in the Syl vaemus group on morphological grounds by G. G. Musser and colleagues in 1996. Its abundance in Europe has made it the subject of many morphological and morpho-anatomical studies as well as genetic ones, as summarized by Musser and M. D. Carleton in 2005. Of the latest molecular phylogenies, that by H. Suzuki and coworkers in 2008 confirmed the position of A. sylvaticus in a Sylvaemus group and a A. sylvaticus clade including A. alpicola, A. flavicollis, and A. ponticus, while the Liu Qi team in 2012 and J. Darvish and colleagues in 2015 found A. sylvaticus to besister taxon of a clade including A. flavicollis + A. uralensis + A. alpicola . Monotypic.

Distribution. Widespread in Europe (from Iceland, Britain, and Iberia E to S Norway, S Sweden, Belarus, SW European Russia, E Ukraine, and the Balkan Peninsula) and in coastal and mountainous regions of Morocco, Algeria, and Tunisia.

Descriptive notes. Head-body 80-110 mm, tail 70-115 mm, ear 15-18 mm, hindfoot 20-23 mm; weight 14-30 g. The Long-tailed Field Mouse, a small brownish mouse with large naked ears and bicolored tail, has dorsal pelage rufous brown or gray and ventral pelage grayish white. Tail is long (c.107% of head-body length), with small scales arranged in rings, and is brown above and white below. Colors ofdorsal and ventral pelage vary geographically in darkness/paleness. Females bear three pairs of mammae. Chromosomal complement has 2n = 48, FN = 43.

Habitat. Long-tailed Field Mice prefer forest or forest edges but are found in wide variety of habitats, from deciduous to coniferous forests and to gardens, hedgerows, or cultivated fields, from sea level to 2000 m elevation.

Food and Feeding. This Long-tailed Field Mouse is omnivorous, but predominant food is seeds and acorns, followed by fruits, flowers, stems, fungi, and insects, snails, and earthworms,all these in variable proportions. It forages in trees or on/in ground.

Breeding. Reproduction is dependent on locality and weather conditions, occurring mainly during spring, summer, and beginning of autumn, but in favorable climate during whole year. Gestation period is 20-22 days, and litter consists of 2-9 (average 4-5) young. Blind and naked at birth, young open eyes at day 13 and are weaned at 18-21 days. Young born in spring may reproduce during same season; those born in autumn will reach sexual maturity in following spring. In study of paternity of offspring of females from wild Long-tailed Field Mouse populations in Northern Ireland, number of embryos varied from fourto six and these (as well as females) were genotyped: 53-8% of litters showed multiple paternity (up to three different males per litter) during May-July, which suggested common polyandry among females of this species, as well as probable polygynous males.

Activity patterns. The Long-tailed Field Mice is nocturnal, arboreal, and subterranean. It is a good climber and can jump well. Nests are either in trees or in burrows or natural subterranean shelters. It digs burrows that contain a nestlined with dry vegetation and a storage chamber.

Movements, Home range and Social organization. A study in England found that, when cerealfields in which Long-tailed Field Mice foraged were harvested, the mice either reduced their activity or moved to more suitable vegetation patches: of 32radiocollared individuals, 17 were caught by predatorsin less than a week after harvest, and this, combined with emigration, meant that the species’ population in the field was reduced by 80%. Long-tailed Field Mice can reach density of 50-100 ind/ha. Radiotracking of adult males in deciduous woodland during breeding and non-breeding seasons revealed that home range was five times larger in breeding season; territories in woodland were 28 times smallerthan those in sand-dune habitats; mean speed of mice was higher in sand dune (3-4 m/s) than in woodlands (1-4 m/s) during breeding season and slower in non-breeding period; average total distance traveled per night was 320 m in woodland against 1201 m in sand dune. In Mediterranean agro-forestry environments, another radio-tracking study showed high variability in home range size, reaching mean of 1-1 ha + 0-92 SD, with no difference between sexes. Population density varies according to available resources and with seasonal variation in acorn supply on ground. During winter large communal nests are used. Communal breeding occurs, but apparently only when ecological factors oblige females to raise young together, and involving only dominant and non-dominant females of same family. Dominant sisters or unrelated females never breed communally.

Status and Conservation. Classified as Least Concern on The IUCN Red List because the speciesis widespread and very common.

Bibliography. Aulagnier et al. (2009), Booth et al. (2007), Corbet (1978), Corp et al. (1997), Darvish et al. (2015), Gerlach & Bartmann (2002), Happold (2013a), Liu Qi et al. (2012), Michaux et al. (2003), Musser & Carleton (2005), Musser et al. (1996), Quéré & Le Louarn (2011), Rosalino et al. (2011), Sunyer et al. (2016), Suzuki et al. (2008), Tew & Macdonald (1994).