- The Myotis myotis, commonly known as the Greater Mouse-eared Bat, is one of Europe’s largest bat species and a remarkable example of chiropteran evolution. This impressive bat belongs to the family Vespertilionidae and is widely distributed across Europe, extending into parts of the Middle East and North Africa.
- Physically, M. myotis is a robust bat with adults measuring 67-84 millimeters in body length, with a wingspan of 350-450 millimeters. Females are typically larger than males, exhibiting notable sexual dimorphism. Their fur is characteristically brown to greyish-brown on the dorsal side, contrasting with a distinctive white to off-white ventral surface. The face is typically flesh-colored, and the ears are notably long and broad, containing highly sensitive structures for echolocation.
- The species possesses several specialized adaptations for efficient flight and hunting. Their wings are broad and relatively long, enabling both agile maneuvering and energy-efficient sustained flight. The tragus, a prominent structure within the ear, is long and pointed, playing a crucial role in their sophisticated echolocation system. Their eyes, while small, are functional, complementing their primary sensory system of echolocation.
- In terms of habitat preference, Greater Mouse-eared Bats are highly adaptable, utilizing various environments including deciduous and mixed woodlands, parklands, and agricultural areas. During summer, they primarily roost in warm, spacious attics, church steeples, and other human structures, while in winter, they hibernate in caves, mines, and other underground sites where temperatures remain stable and above freezing.
- Their hunting strategy is particularly fascinating, as they specialize in gleaning prey from the ground rather than catching insects in flight. Using their exceptional echolocation abilities, they can detect prey moving on the forest floor from a height of several meters. Their primary prey consists of large ground-dwelling arthropods, particularly carabid beetles and other large insects, though they will also take other invertebrates when available.
- Social organization in M. myotis is complex, with females forming large nursery colonies during the breeding season, sometimes numbering several thousand individuals. Males, in contrast, generally roost solitarily or in small groups during summer. During the mating season in autumn, males establish temporary territories and attract females through specific vocalizations and behaviors.
- The reproductive cycle is typical of temperate zone bats, with mating occurring in autumn before hibernation. Females store the sperm through winter, with fertilization occurring in spring after emergence from hibernation. Usually, a single pup is born in early summer after a gestation period of 50-70 days. The young develop rapidly, beginning to fly at about 3-4 weeks of age and becoming independent within 6-8 weeks.
- During hibernation, which typically lasts from October to April depending on geographical location and climate, these bats enter a state of torpor where their body temperature drops significantly and metabolic rate slows dramatically. They may occasionally wake and change position or even feed during milder winter periods.
- The Greater Mouse-eared Bat faces various conservation challenges, primarily due to human activities. Disturbance of hibernation sites, loss of summer roosts due to building renovation or exclusion, and changes in agricultural practices affecting prey availability are significant threats. The species is protected under European legislation, and various conservation measures are in place to protect both their summer and winter roosts.
- One of the most remarkable aspects of M. myotis is their longevity, with individuals known to live up to 37 years in the wild, extraordinarily long for a small mammal. This longevity, combined with their low reproductive rate, makes populations particularly vulnerable to disturbance and highlights the importance of effective conservation measures.
- Their role in ecosystem services is significant, as they contribute to the control of various insect populations, including several agricultural pest species. This makes them not only fascinating creatures from a biological perspective but also valuable components of natural pest control systems in agricultural landscapes.
