Based on analyses of sequence data of mitochondrial genes, Castella et al. (2000) and Ruedi and Mayer (2002), Simmons in Wilson and Reeder (2005) treated myotis, blythii, oxygnathus and punicus as separate species, an arrangement used also by Spitzenberger (2002). However, the IUCN SSC Chiroptera Specialist Group awaits further details to justify the specific separation of M. blythii and M. oxygnathus. We follow Castella et al. 2000 in treating the populations of North Africa, Corsica, Sardinia and Malta as a species: M. punicus.

The species is declining in France, Portugal, Spain and Turkey, but is stable in the Balkans. The assessment for the Mediterranean is like that for Europe, i.e. Near Threatened (overall, population declines may approach 30% over the last 21 years (3 generations) thus almost qualifying as VU under A2b). But this species merits closer attention, as it may well qualify for a threatened category in the near future. There is no rescue effect.

A south-west Palearctic species, it occurs in southern Europe, southern parts of central Europe, and non-arid parts of southwestern Asia from Asia Minor, the Caucasus region and Palestine to Kashmir, the Altai mountains, Nepal, and parts of China. The subspecies M. b. oxygnathus occurs in Mediterranean Europe and western Anatolia: Portugal, Spain, France, Italy (including Sicily). Switzerland, Austria, Czech Republic, Slovakia, Romania, Moldova, Ukraine (including Krym), the Balkan Peninsula and parts of Turkey (Topál and Ruedi 2001). In the Caucasus, Turkey, Iran, the Russian Federation and Georgia it is confimed to occur no higher than 1,700 m (K. Tsytsulina, M. Sharifi and A. Karatash pers. comm. 2005). However, it is found at altitudes of up to 2,100 m in the winter in southern Spain (Palomo and Gisbert 2002).

A gregarious species, it congregates in nursery and/or hibernating colonies of up to 500 individuals. There have been large population reductions since the 1950s in several areas, including central Europe, Israel, and central Asia, and there is evidence of ongoing decline in some parts of the range, although in other areas populations appear stable. In parts of its range it remains an abundant species. In Turkey it occurs in large clusters and is the second most common bat species (A. Karatash pers. comm. 2007). In Iran there is evidence of population decline, although it remains one of the most sighted species (M. Sharifi pers. comm. 2005). The Spanish population is estimated to be smaller than 20,000 individuals, and is concentrated in the southern part of the country (Palomo and Gisbert 2002). It is declining, at a rate of one third over the last 10 years in important large colonies in Andalucia (Franco and Rodrigues de los Santos 2001). It is one of the rarest species in Portugal, where its population of c.2,000 individuals is declining (Rodrigues et al. 2003). It is uncommon in the northern part of the range (Austria) but seems stable (Spitzenberger 2002). In France, the population of over 20,000 individuals experienced declines since the 1960s, but may now be stable (S. Aulagnier pers. comm. 2006). In the Balkans, it is regarded as stable (Mediterranean workshop 2007). In Romania, one well-known colony has declined by 95% as a result of disturbance by speleological tourism (Z. Nagy pers. comm. 2006).

In South Asia the population is considered stable (Molur et al. 2002).

It often occurs in mixed colonies with Myotis myotis and identification is sometimes problematic.

It forages in scrub and grassland habitats, including farmland and gardens. Maternity colonies are usually found in underground habitats such as caves and mines, and sometimes in attics of buildings (particularly in central Europe). In Iberia and in the Balkans it is mainly found in caves and other underground sites (e.g., mines). In Turkey and Syria maternity colonies are found in caves and in very old buildings (castles, inns, etc.). It hibernates in winter in underground sites with a relatively constant temperature of 6-12ºC. The species is an occasional migrant, with movements of up to 488 km recorded (Hutterer et al. 2005; previous reports of 600 km are erroneous).

Changes in land management, especially agricultural pollution and other agricultural activities, can affect populations of this species. Disturbance to roosts in caves and buildings may also be a problem.

In some caves used by speleologists in Spain, the disturbance affects more than 90% of the population and some large historical colonies in southern Spain have disappeared as a result. The Andalucian population decreased from 30,000 individuals to 14,000 between 1994 and 2002 (unpublished report submitted to Junta Andalucia government).

In Turkey and Syria caves are often used by herders and their livestock; the herders light fires in the cave entrances which disturb the bats.

It is protected by national legislation in most range states. There are also international legal obligations for its protection through the Bonn Convention (Eurobats) and Bern Convention in range states where that applies. It is included in Annex II (and (IV) of EU Habitats and Species Directive, and hence requires special measures for conservation including designation of Special Areas for Conservation. There is some habitat protection through Natura 2000. In some countries (including Spain, Portugal, and Italy) several colonies are protected by closing entrances to caves with fences. More colonies should be protected, however, the emphasis needs to be on better protection of cave sites generally rather than on 'gating' of cave entrances which is often detrimental to bats causing direct mortality and abandonment of caves.