Bechstein bat (Myotis bechsteinii)

In Izki

The characteristics of the Pyrenean oak wood of Izki with relatively mature feet, woodpecker holes and points with stable and calm water are ideal for this species. In fact, the presence of Myotis bechsteinii has been confirmed in Izki and a breeding colony in woodpecker nests has been located, probably the middle spotted woodpecker.

Reused Dwelling

It is a medium sized bat (forearm between 39-47 mm) and eminently forest dwelling, preferably linked with oak woods of Quercus robur and Quercus pirenaica.

It is distributed throughout central and southern Europe although it is considered a rare species throughout the area, it is only abundant locally. In the Iberian Peninsula it is considered to be of discontinuous distribution, linked to forest areas with an abundance of old trees. In the Basque Autonomous Region it has only been found in the Historic Territory of Alava and is catalogued as “in danger of extinction”.

The Bechstein bat establishes its reproduction colonies in the hollows of trees, almost exclusively those created by woodpeckers. No hibernation colonies are known and it is considered that the specimens found in subterranean cavities during this period usually seek refuge there. 
The breeding colonies are closed social groups between 5 and 30 individuals, made up by related females who divide and regroup constantly, occupying various close refuges at a time. The microclimatic conditions of the refuges seem to be decisive when choosing, since they are directly related with the metabolic requirements of the specie and can even have an impact on the success of reproduction.

The home range of the Bechstein bat is between 5 and 10 ha, with movements within a radius of approximately 1 km around the refuge and relatively short migration of some 35 km between seasons.

Its food is anthropod and insect based which it hunts at night, which is why they are frequently associated with the presence of water relatively close to their refuges. The presence of surface of water free of vegetation during the breeding season (in July) is fundamental to provide the females the necessary water and food they need to successfully breed their offspring.

The loss of old tress, which provide adequate refuges for the species and the modification of its hunting habitats are considered to be the main threats for this bat.