The Natterer’s Bat (Myotis nattereri) inhabits diverse landscapes across Europe and parts of Asia. This species plays a role in its ecosystems, offering insights into the health and balance of natural environments.
Unveiling Natterer’s Bat
The Natterer’s bat (Myotis nattereri) is a medium-sized species. Its head and body typically measure between 40 to 50 mm, with a wingspan ranging from 245 to 300 mm. These bats weigh approximately 7 to 12 grams.
The fur on its back is a light buff-brown, contrasting with a noticeably white underside, creating a clear division. A distinctive feature is the bare, pink face and pinkish limbs, which led to its older name, “red-armed bat.” The ears are relatively long, narrow, and slightly curved backward at the tip, featuring a long, narrow, and sharply pointed inner lobe called the tragus. A fringe of stiff bristles lines the trailing edge of its broad tail membrane.
A Bat’s World: Habitat and Habits
Natterer’s bats are found across most of Europe, extending into parts of the Near East and North Africa. Their distribution spans from northern Europe to Central Asia and North Africa. They inhabit a variety of environments, including forests, parkland, and open countryside with scattered woodlands, and can be found from sea level up to altitudes of 2,000 meters.
During the summer, Natterer’s bats commonly roost in old stone buildings like castles, manor houses, churches, and large timbered barns, often using crevices or gaps. They may also use tree cavities or bat boxes, with maternity colonies, comprising 30 to 200 females, forming from May to July. These bats emerge late in the evening to forage and return to their roosts before sunrise, sometimes changing sites frequently.
Foraging occurs in broad-leaved woodlands, along tree-lined rivers, ponds, and even over grasslands. They fly at a slow to medium speed, demonstrating maneuverability, especially among trees, and typically fly at heights less than 5 meters. Their echolocation calls are quiet, ranging from 35 to 80 kHz, with a peak around 50 kHz, enabling them to detect prey close to vegetation. Natterer’s bats glean insects directly from surfaces like foliage or the ground.
Ecological Role of Natterer’s Bat
Natterer’s bats are insectivorous, feeding on a variety of invertebrates. Their diet includes flies, especially midges, small moths, caddis flies, lacewings, beetles, small wasps, and spiders. They catch prey both in flight and by gleaning from surfaces, such as snatching spiders from webs or picking up invertebrates from the ground.
This foraging behavior makes them effective natural pest controllers within their ecosystems. By consuming insects and other arthropods, Natterer’s bats help regulate insect populations. Their ability to glean prey from vegetation and the ground means they target insects that might otherwise be inaccessible to other aerial predators.
Protecting Natterer’s Bat
The Natterer’s bat is listed as “Least Concern” globally by the IUCN Red List of Threatened Species, due to its wide distribution and stable population trend. However, the species faces threats at local and regional levels. Habitat loss is a concern, stemming from deforestation, disturbance of roost sites, and renovations of old buildings that serve as summer colonies.
Pesticide use reduces the availability of their insect prey and can lead to direct poisoning. Climate change impacts on insect populations and habitat suitability are also concerns. To address these challenges, Natterer’s bats are protected under various international agreements, including the European Habitats Directive 92/43/EEC, the Bonn Convention (EUROBATS), and the Bern Convention. Conservation efforts preserve roosting sites and foraging habitats, promote sustainable land management practices, and raise public awareness about bat conservation.