[3][4] It was previously classified within the Brandt's bat (M. brandtii), but more recent phylogenetic studies have found deep genetic divergence between both taxa, indicating that both are distinct species from one another, and they have thus been split by authorities including the American Society of Mammalogists, the IUCN Red List, and ITIS.

[7] Populations in Siberia have exceptionally long hibernation periods, beginning in late September and continuing through mid-June of the following year.

[10] Compared with other animals its size, it lives 9.8 times longer than expected, which is the greatest value of any mammal with a known lifespan.

[8] Longevity quotient This species is thought to have a declining population due to forest degradation and fragmentation, as well as the loss of roost sites in caves.

The primary cause of forest loss is urban development, with deforestation and wildfires also playing a role in the decline.

However, it has a wide population and is not thought to be declining at a rate that would qualify it for a more imperiled status, so it is classified as Least Concern.