486.

Lesser Myotis

Myotis blythii

French: Petit Murin / German: Kleines Mausohr / Spanish: Ratonero mediano

Other common names: Lesser Mouse-eared Bat, Lesser Mouse-eared Myotis

Taxonomy. Vespertilio blythii Tomes, 1857,

“ India, Nassenabad.”

Subgenus Myotis, myotis species group (11 species). The taxonomic distinctions between M. blythii, M. myotis, and M. punicus are difficult to discern and the three species have been lumped under M. myotis or recognized as two species, M. myotis and M. blythii (including M. punicus as a subspecies). However, the three species are considered distinct here based on substantial genetic data supporting the specific status of all three. There are reports of hybrids between this species and M. myotis, however, and the taxonomic relationship between the two speciesis still somewhat controversial. Six subspecies are often recognized ( blythii, ancilla, lesviacus, omari, oxygnathus, and risorius), although there is substantial local morphologicalvariation that may account for the variation reported in these subspecies. However, it has been suggested that some of these names (particularly ancilla, omar, and oxygnathus) may represent distinct species. Considered monotypic here pending furtherstudiessince the distributions of individual subspecies are rather undefined.

Distribution. SC & S Europe (including Sicily, Cyprus, Crete, and smaller Mediterranean Is), SW Asia from Asia Minor, the Caucasus region, Palestine, and N Jordan to Kashmir, the Altai Mts, Nepal, N India, and N & C China.

Descriptive notes. Head-body 54-76 mm, tail 59 mm, ear 21-24- 3 mm, hindfoot 11- 15 mm, forearm 50-5—-62- 1 mm; weight 19-29- 5 g. The Lesser Myotisis one of the largest bats in its distribution. Dorsalfuris brownish; venteris pale gray, whitish, or beige. Some individuals have white spot on their foreheads, but this is not diagnostic becauseitis inconspicuous on many individuals. Ears are generally long and triangular, covering pointed pale tragus that does not have dark tip. Snoutis relatively short, which is reflected on short upper mandibles and C-M® distance of 8:1-9- 5 mm. Greatest length ofskulls are 21-2-22- 7 mm, condylo-basal lengths are 20-4-21- 9 mm, and zygomatic breadths are 13- 7-15 mm. Skull is large with robust rostrum and low braincase compared to unrelated Myotis; forehead region is moderately concave and sagittal crest is strongly developed. P? is about one-half height and crown area of P2or less and is within tooth row. Chromosomal complement has 2n = 44 and FNa = 50 (Turkey) or 52 (Greece).

Habitat. Mainly scrub and grassland habitats in steppes, pastures/meadows, karst, and agricultural areas from sea level up to elevations of ¢. 2100 m.

Food and Feeding. The Lesser Myotis mainly eats bush-crickets, chafers, grasshoppers, crane flies, ground beetles, mole crickets and, in Mediterranean areas, praying mantises and lepidopteran caterpillars. Lesser Myotis can either capture insects in flight (aerial hawking) or directly from the ground (gleaning), depending oninsect availability and vegetation clutter. It usually forages 1-2 m aboveground, continuously scanning the surface for potential prey, and positively selects open spaces to forage. Insects are captured by landing directly on top of them or by agilely intercepting them in flight. It can hunt in pastures with long grass full of crickets. It also forages intensively in forest edges where insect availability tends to be higher than in other more homogenous habitats.

Breeding. Mainly adult females and their offspring form maternity colonies that can have hundreds of individuals, and males roost alone or in small clusters nearby the main maternity roost. Some of colonies form specifically for the maternity period,if cave conditions allow it; these can be sedentary, with individuals staying in the same roost year-round. Females give birth between the end of May and mid-June, commonly to one young. Timing of parturition is determined by food availability. Young begin to fly at 5-6 weeks old. In some areas of sympatry, Lesser Myotis and Greater Myotis ( M. myotis) interbreed and produce viable hybrids.

Activity patterns. Lesser Myotis typically emerge well after sunset, after pipistrelles ( Pipistrellus) and Schreibers’s Long-fingered Bats ( Miniopterus schreibersii), and return to roosts before dawn. In the northern part ofits distribution,it roosts in attics, old buildings, and churches; in the southern part, it mostly roosts in caves, tunnels, and mines. Echolocation is also very similar to that of the Greater Myotis, with highly modulated calls of 120-170 kHz down to 26-29 kHz, peak frequency usually of c.35 kHz, and durations of ¢.2-10 milliseconds.

Movements, Home range and Social organization. No regular long movements have been documented for the Lesser Myotis, although maximum distance traveled was c. 488 km. Maternity and hibernation roosts are usually c. 15 km apart; thus, it is generally considered non-migratory or an occasional migrant. Lesser Myotis will share roosts with other bat species such as Schreibers’s Long-fingered Bat, some rhinolophids, and other cave-dwelling species, with which they sometimes form mixed clusters. While colonies usually have 50-500 individuals, there are some exceptional colonies with up to 8000 individuals in Bulgaria. Although very little is known about hibernation of Lesser Myotis, there are some reports of relatively large hibernation colonies in underground roosts (hundreds of individuals), alwaysat stable temperatures of 6-12°C. When young are fully independent, swarming usually starts around August. Males have their own sites from where they display, either in flight or by hanging from thesite. Swarming sites include specific locations in cave ceilings, crevices in bridges or old buildings, or cracks in walls. Males defend their territories (display site) against conspecifics and rivals. Sometimes 5-6 females have been lured to the swarming spot of one male. Glandular secretions of males also attract females.

Status and Conservation. Classified as Least Concern on The IUCN Red List. In countries where populations of Lesser Myotis are stable (e.g. northern part ofits distribution, Asia, or Turkey), it is considered abundant. In Spain and Portugal,its populations are currently decreasing, and it is sometimes considered one of the rarest bats. Because it is cave dwelling, major threats such as speleology play a key role in recent population declines, such as in Romania where one of the most important colonies was almost extirpated in a relatively short time. Tourism and cave disturbance by herders are also crucial factors in their conservation. Abandonmentof agricultural areas and recovery of bushes and secondary forest dramatically reduce suitable foraging habitat of the Lesser Myotis .

Bibliography. Arlettaz (1996a, 1999), Arlettaz, Christe et al. (2001), Arlettaz, Perrin & Hausser (1997), Arlettaz, Ruedi & Hausser (1991), Arlettaz, Ruedi, Ibanez et al. (1997), Asan etal. (2010), Bachanek & Postawa (2010), Benda & Horagek (1995), Berthier et al. (2006), Castella et al. (2000), Evin et al. (2008), Furman & Ozgill (2004), Furman et al. (2014), Ghazali (2008), Glittinger et al. (1998), Hassan et al. (2010), Hutterer et al. (2005), lliopoulou-Georgudaki (1984), Juste & Paunovié¢ (2016d), Mayer & von Helversen (2001), Molur et al. (2002), Piksa (2006), Russo, Jones & Arlettaz (2007), Sharifi (2004b), Sharifi & Akmali (2006), Volleth & Heller (2012).