Further evidence for the post-release survival of hand-reared, orphaned bats based on radio-tracking and ring-return data

We recently used radio-tracking to demonstrate short-term, post-release survival of five orphaned, hand-reared pipistrelle bats. Here, we present further evidence of short-term, post-release survival and also demonstrate longer term survival using re-sighting data of ringed common (Pipistrellus pipistrellus) and soprano (Pipistrellus pygmaeus) pipistrelle bats. Ten bats (five common and five soprano pipistrelles) were radio-tracked for between one and ten days. Three of these were retrieved after one, two and four days, respectively. In addition, five of the 39 (13%) ringed bats returned to their release boxes between 38 and 1,389 days after release, at least two of which survived over the winter in the wild. A sixth ringed bat was retrieved 27 days after release after becoming trapped in a house. We also identified potential barriers to successful rehabilitation. Two of the ten bats radio-tracked in the current project became trapped within buildings and another bat had to be retrieved following entanglement with debris. We therefore recommend that attention be paid to giving bats the opportunity, prior to release, in identifying and using small exit holes similar to those found in buildings and loft spaces. We also recommend allowing bats to self-release following prolonged pre-release flight training in a large flight cage situated in suitable bat habitat.