437.

Pond Myotis

Myotis dasycneme

French: Murin des marais / German: Teichfledermaus / Spanish: Ratonero lagunero

Other common names: Pond Bat

Taxonomy. Vespertilio dasycneme Boie, 1825,

Jutland, Denmark.

Subgenus Myotis; sole member of the dasycneme species group. The relationship of M. dasycneme to other species in the subgenus Myotis is relatively uncertain and there do not appear to be any species closely related to M. dasycneme, supporting the recognition of its monospecific species group. The forms major and lmnophilus are synonyms of dasycneme . Monotypic.

Distribution. C & E Europe, from S Sweden to N France, Germany and Poland, and E to Yenisei River in C Russia; isolated populations in Hungary, Romania, Ukraine, and N Kazakhstan.

Descriptive notes. Head—body 57-68 mm, tail 46-51 mm, ear 17-18 mm, hindfoot 11-12 mm, forearm 43-49 mm; weight 13-18 g. Fur is shaggy. Dorsal pelage of the Pond Myotis is brown to grayish brown; ventral pelage is lighter gray to yellowish white. Bare face and arms are brown and ears and membranes are grayish brown; there are characteristic dark warts on sides of snout. Ears are relatively short with no notch on outer edge; tragus is shorter than one-half the ear height and is relatively broad compared to congeners. Wings attach at heel and feet are large and strong with long bristles (similar to the Long-fingered Myotis, M. capaccinii). Calcar is straight but comparatively short, only extending one-third the way to tailtip. Skull has relatively flat forehead region and comparatively well-developed sagittal crest near posterior portion of cranium. Chromosomal complement has 2n = 44 and FNa = 52 (Russia).

Habitat. The Pond Myotis occurs from sea level up to 1500 m, almost always strongly dependent on aquatic habitats, such as canals, rivers, streams, lakes or ponds; commonly by slow-flowing, broad rivers. During summerit occurs in lowland meadows and forests but it moves to the foothills during autumn and winter.

Food and Feeding. Commonly seen hunting on canals,rivers or lakes, especially those with open banks. The Pond Myotis is one of the few species specialized in feeding above open,still water surfaces using a trawling foraging strategy, involving the uropatagium. This foraging strategy allows it to capture prey straight off still water surfaces, even emerging chironomid midges. It tendsto fly a little higher and faster (7-9 m /s) than Daubenton’s Myotis ( M. daubentonii) or the Long-fingered Myotis, thus preferring clutter-free banks. This species sometimes forages at forest edge and over meadows, and sporadically even over the sea, during the mass emergence of small crabs. It feeds mainly on aquatic insects such as gnats, mosquitoes and caddisflies over water, and beetles and moths at forest edge.

Breeding. Maternity colonies usually harbor less than a hundred females, but in few cases, can number up to 750; males rarely form colonies of more than a few dozen. Females became sexually active during their second year. Sometimes, two young are born. Life span reported to be up to 21 years.

Activity patterns. Roosts tend to be in houses or other old buildings, in attics, churches or empty cavities in roofs; only occasionally in trees, rock crevices, or bat boxes. Colonies of several thousand roosting together have occasionally been found in Denmark. Echolocation calls resemble the typical pulses of all European Myotis, with broadband FM signals,starting at 65-85 kHz and ending at 25-35 kHz.

Movements, Home range and Social organization. Not a long-distance migrant, but it can migrate from lowlands to low mountains. During hibernation, it tends to shift roosts, and roosts either individually or in small clusters, in cellars, caves or bunkers. Winter roosts tend to be separated from summer ones by distances of 100-350 km; for commuting between thesites the species needs quality forest for connecting corridors.

Status and Conservation. Classified as Near Threatened on The IUCN Red List. There are no estimates but populations are suspected to have slumped in recent decades, especially in the Netherlands; now one of rarest bat species in Europe. Continued degradation of aquatic habitats, water pollution and destruction of riparian habitats might compromise its survival in the near future; roost disturbance and loss are also major threats, and many of the known maternity colonies have been lost in recent decades. More information is needed from the eastern part ofits distribution.

Bibliography. Britton et al. (1997), Ciechanowski & Zapart (2012), Ciechanowski, Sachanowicz & Kokurewicz (2007), Ciechanowski, Zapart et al. (2017), Hutson et al. (2001), Krlger et al. (2012), Kuijper et al. (2008), Leeuwangh & Volte (1985), Limpens et al. (2000), Orlova & Zapart (2012), Pacifici et al. (2013), Piraccini (2016f), Reinhold et al. (1999), Roer (2001), Van de Sijpe et al. (2004), Verboom et al. (1999), Volleth & Heller (2012), Volte et al. (1974).