480.

Bechstein’s Myotis

Myotis bechsteinii

French: Murin de Bechstein / German: Bechstein-Fledermaus / Spanish: Ratonero forestal

Other common names: Bechstein's Bat

Taxonomy. Vespertilio bechsteinii Leisler in Kuhl, 1817,

Hanau, Hessen, Germany .

Subgenus Myotis; daubentonii species group. See M. daubentonii . Monotypic.

Distribution. Europe, from S Sweden, S of Britain, and Iberian Peninsula to Ukraine, Greece, and Thrace (including Corsica and Sicily Is in the Mediterranean), isolated areas in SW Asia including Turkey (Anatolia) and the Caucasus region.

Descriptive notes. Head—body 38-55 mm, tail 30-47 mm, ear 20-26 mm, forearm 39-47 mm; weight 7-14 g. Fur of Bechstein’s Myotis is relatively long and shaggy, brownish or reddish (pale or grayish in young), with clear distinct between dorsum and venter. It has long muzzle, bare pink face that is much slimmer than in other congeners, and distinctly long and separated ears that have 9-11 transverse folds on external margins. Tragus is long and lance-shaped and reaches one-half the ear length when extended. Wings are dark, short, and wide, useful for foraging in cluttered forests. Condylo-basilar lengths are 16-17 mm. Chromosomal complement has 2n = 44 and FNa = 52 (Greece and Turkey).

Habitat. Only temperate old growth or mature forests and woodlands (preferably beech and oak forests) from sea level up to elevations of ¢. 1500 m. Bechstein’s Myotis is very dependent on natural roosts (e.g. tree holes, trunk crevices, and bird nests, such as woodpecker holes), but it will use bat boxes and occasionally buildings. It very rarely is found in agricultural land, gardens, or plantations.

Food and Feeding. Bechstein’s Myotis feeds on Lepidoptera (mostly) and non-flying insects such as Coleoptera, Diptera, and Planipennia that it gleans from the ground and leaf surfaces. Its high maneuverability allows it to hunt very close to the ground and vegetation (1-5 m away) and to fly very slowly and hover, waiting for prey to make any noise to allow detection.

Breeding. Maternity colonies have 10-50 females (rarely up to 100 individuals) and occur from ground level up to 20 m. Males are commonly solitary. Maternity colonies usually form by April, with births taking place from beginning ofJune to beginning ofJuly. In late August, individuals start to disperse and mate at swarmingsites. In some cases, several species of bats coexist in the same colony. In general, it is assumed that breeding colonies change location every 2-3 days. Maximum longevity is 21 years in the wild.

Activity patterns. Bechstein’s Myotis emerges usually ¢.20 minutes after sunset. It commonly roosts in tree holes in summer and winter but hibernates in caves, mines, buildings, and underground tunnels. Echolocation is long broadband FM of 35-100 kHz, being almost always indistinct from other congeners if not complemented by visual observations.

Movements, Home range and Social organization. Bechstein’s Myotis can shift roosts between summer and winter. Although it has been recorded up to elevations of ¢. 1500 m, maternity colonies are usually found below 800 m. Foraging sites of a maternity colony usually do not exceed 250 ha, with 1-10 km between roosts and foraging areas. Some individuals have hunting areas of up to 700 ha in continuousforest.

Status and Conservation. Classified as Near Threatened on The IUCN Red List. Bechstein’s Myotis is not only very uncommon (especially in the South) but also a strict forest-dwelling specialist of old primary forests. It is only locally abundant in certain parts of Central Europe. Its populations seem to be heavily fragmented due to past forest exploitation, and colonization of new habitatis rarely reported. It is one of the most common and abundant bat species in the fossil record.

Bibliography. Benzal & de Paz (1991), Fitzsimons et al. (2002), Goiti et al. (2007), Hutterer et al. (2005), Kerth & Konig (1999), Kerth & Petit (2005), Kerth et al. (2001), Napal et al. (2009, 2010), Pacifici et al. (2013), Paunovié (2016b), Reckardt & Kerth (2006), Schlapp (1999), Sharifi et al. (2000), Théou & Durovi¢ (2015), Volleth & Heller (2012), Wolz (2002).