Myotis myotismouse-eared bat

Geographic Range

This species is found throughout Eurasia and part of northern Africa. It has gone extinct in the United Kingdom after 1990.


M. myotis primarily inhabit caves and buildings such as churches and castles. They also dwell in relatively open, lightly wooded forests.

Physical Description

M. myotis are relatively large bats, with long ears, overall length 6.5-8.0 cm, broad wingspan 36.5-45.0 cm, and forearm length about 5.7 cm. Adult body weights are about 20-45 g. Females are larger than males.

M. myotis are very similar to M. blythii phisically.
  • Range mass
    20 to 45 g
    0.70 to 1.59 oz
  • Range length
    6.5 to 8.0 cm
    2.56 to 3.15 in
  • Range wingspan
    36.5 to 45.0 cm
    14.37 to 17.72 in


M. myotis are early breeders. Ovulation and fertilization may take place during February mostly, or in October if birth occurs in winter. Gestation period is about 60-70 days. Births take place mostly in April to June, but some were observed in winter. After birth, young M. myotis remain fixed on their mothers for about 2 weeks. Female M. myotis mate again as soon as the young become independent. Females store sperm in the uterus, but eggs are not fertilized until the next spring.
Babies are born with claws on their hind feet and milk teeth. They are blind at birth. The young become independent after 2 months and start to feed on insects. They must accumulate sufficient fat reserves for hibernation.
  • Breeding season
    Late spring to summer.
  • Range number of offspring
    1 to 2
  • Average number of offspring
  • Average number of offspring
  • Range gestation period
    60 to 70 days
  • Average weaning age
    60 days
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    502 days
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    502 days


Life span in Myotis is usually 6 to 7 years, but M. myotis were recorded as 13 years old in the United Kingdom. In wild, some may survive up to 22 years.


M. myotis are nocturnal. They possess a large activity space with a radius of around 10 km. The distance between their summer and winter accommodations can be over 10 km. They usually live in groups and each group can be around 10-100 individuals. They prefer caves or attics, but sometimes also roost in buildings where temperature is not as stable.

They fly relatively low, about 5 to 10 m.

When hibernating, their heart rates drop from 600 to only 18-80 beats per minute.

Communication and Perception

Food Habits

These bats are opportunistic predators. They primarily feed on ground beetles such as carabids (Carabidae), but also prey on large moths and grass beetles whenever possible. M. myotis prefer feeding in open woodland with ground cover of few grasses. They may have evolved to catch ground beetles on the soil surface. However, they may select alternative preys if primary sources do not meet their requirements. They consume around 25-50% of body weight nightly.

  • Animal Foods
  • insects


The main factor that causes decline of M. myotis populations may be human disturbance. People both use agrochemicals which poison bats, or disturb caves that causes death at roosts. In addition, large scale agricultural change has reduced areas of open ground and increase grassland, and this also results in reductions in the number of bats.

Economic Importance for Humans: Positive

  • Positive Impacts
  • controls pest population

Conservation Status

IUCN status category: Low risk, near threatened.

Red book: vulnerable.

Numbers have declined fast recently and the species has gone extinct in northwestern Europe.

Other Comments

Fossil evidence shows the separation of M. myotis from M. blythii occurred during the Pleistocene.


Hui-Yu Wang (author), University of Michigan-Ann Arbor, Bret Weinstein (editor), University of Michigan-Ann Arbor.



living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

World Map


young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


an animal that mainly eats meat


uses smells or other chemicals to communicate


used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.


animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.


forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.


An animal that eats mainly insects or spiders.


makes seasonal movements between breeding and wintering grounds


having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.


active during the night


found in the oriental region of the world. In other words, India and southeast Asia.

World Map


the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

seasonal breeding

breeding is confined to a particular season


reproduction that includes combining the genetic contribution of two individuals, a male and a female


mature spermatozoa are stored by females following copulation. Male sperm storage also occurs, as sperm are retained in the male epididymes (in mammals) for a period that can, in some cases, extend over several weeks or more, but here we use the term to refer only to sperm storage by females.


living in residential areas on the outskirts of large cities or towns.


uses touch to communicate


that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).


Living on the ground.


living in cities and large towns, landscapes dominated by human structures and activity.


reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.


"Ecology of bats in middle european cities" (On-line). Accessed October 7, 2001 at

"Les fiches: Embranchement des Vertebres" (On-line). Accessed October 7, 2001 at

"UNEP World Conservation Monitoring Centre" (On-line). Accessed October 7, 2001 at

Arlettaz, R. 1996. Feeding behaviour and foraging strategy of free-living mouse-eared bats, Myotis myotis and Myotis blythii. Animal Behaviour, 51: 1-11.

Arlettaz, R., M. Ruedi, C. Ibanez. 1997. A new perspective on the zoogeography of the sibling mouse-eared bat species Myotis myotis and Myotis blythii: morphological, genetical and ecological evidence. Journal of Zoology, 242: 45-62.

Arlettaz, R., N. Parrin, J. Hausser. 1997. Trophic resource partitioning and competition between the two sibling bat species Myotis myotis and Myotis blythii. The Journal of Animal Ecology, 66: 897-911.

Audet, D. 1990. Foraging behavior and habitat use by a gleaning bat, Myotis myotis (Chiroptera: Vespertilionidae). Journal of Mammalogy, 71: 420-427.

Ibanez, C. 1997. Winter reproduction in the greater mouse-eared bat (Myotis myotis) in South Iberia. Journal of Zoology, 243: 836-840.

Zahn, A. 1999. Reproductive success, colony size and roost temperature in attic-dwelling bat Myotis myotis. Journal of Zoology, 247(2): 275-280.

Zahn, A., B. Dippel. 1997. Male roosting habits and mating behaviour of Myotis myotis. Journal of Zoology, 243: 659-674.