Project with bat boxes was launched as a result of need to provide roosts for some forest-dwelling or fissure-dwelling species they require holes or fissures in trees for roosting, mating and breeding. Due to the lack of mature forests with old trees and increasing presence of altered habitats, the availability of natural roost has dramatically decreased. Bat boxes are a compensatory measure, and therefore should not be used as definitive replacement for natural roosts.
Nevertheless, it is important to know the number of individuals and which species might occupy them. The monitoring is mainly focused on urban species such as common pipistrelle (Pipistrellus pipistrellus), soprano pipistrelle (Pipistrellus pygmaeus), Kuhl’s pipistrelle (Pipistrellus kuhlii), Nathusius’ pipistrelle (Pipistrellus nathusii) and forest-dwelling species such as Leisler’s bat (Nyctalus leisleri), giant noctule (Nyctalus lasiopterus), brown and grey long-eared bats (Plecotus auritus and Plecotus aurstriacus), greater mouse-eared bat (Myotis myotis), Iberian Natterer’s bat (Myotis escalerai), Bechstein’s bat (Myotis bechsteinii) and western barbastelle (Babastella barbastellus).