Assessment of the short-term success of a translocation of lesser short-tailed bats Mystacina tuberculata

Abstract

Translocation is a powerful tool that has been used in the conservation of a wide range of taxa. However, few translocations of bats have been attempted and we know of no successes. The few translocations which have been attempted have either failed due to dispersal from the release site or have not been monitored sufficiently to determine the cause of failure. We assessed the shortterm success of a translocation of lesser short-tailed bats Mystacina tuberculata by the New Zealand Department of Conservation, where 3 release methods were used to minimise dispersal or mortality: bats were juveniles, were maintained in captivity at the release site, and were provided with supplementary food and roosts following release. Success was assessed by determining if founders remained at the release site and maintained condition (weight). Recapture showed that at least 9 of the 20 bats remained at the release site 232 d after release. There was weak evidence that bats lost weight, although final weights were comparable to those of bats from a natural population. However, all bats captured 8 mo after release had damaged, infected ears and some were balding. The problem was treated but recurred, and bats were returned to captivity. Our results are the first to demonstrate that translocated bats can remain at their release site and survive. However, disease may be an issue in future translocations.

Social implications of a colony collapse in a highly structured vertebrate species (long‐tailed bat, Chalinolobus tuberculatus)

“…Few bat translocations for conservation have been attempted and none have proven successful (Ruffell et al ., ). The only translocations of bats for conservation in New Zealand to date involved attempts to establish short‐tailed bats, Mystacina tuberculata , on two offshore islands from which bats had been extirpated by introduced mammalian predators (these island have subsequently been eradicated of the mammalian predators; Ruffell et al ., ; Ruffell & Parsons, ). A translocation of 20 juvenile short‐tailed bats to Kapiti Island failed due to disease (all bats caught after 8 months had damaged, infected ears and were taken into captivity; Ruffell & Parsons, ) and a translocation of 50 bats to Ulva island failed, likely due to bats dispersing from the island (B. Lloyd, unpubl.…”

The conservation status of New Zealand bats, 2009

“…There is one instance of lesser-short-tailed bats contracting an unknown skin disease following translocation to Kapiti Island (Ruffell & Parsons 2009). Eight bats captured 232 days after release had scabbing on the distal end of their pinnae, while an additional two animals had severe swelling at the basal end.…”

“…Furthermore, there are no populations of central lesser short-tailed bats secure on predator free offshore islands. Other threats include habitat loss through logging in some areas, disease and potential secondary poisoning from use of pest control toxins (Lloyd & McQueen 2000;Griffiths 2002;Ruffell & Parsons 2009). …”

First breeding and hand rearing of the New Zealand lesser short‐tailed bat Mystacina tuberculata at Auckland Zoo

“…The Zoo's bats originate from a group that was collected from the lower North Island of New Zealand for translocation to a predator‐free offshore island in 2005 (Ruffell & Parsons, ). Twenty‐five pregnant ♀♀ were captured from a population in the Tararua Range in December 2004, transferred to the Mount Bruce Wildlife Centre, Masterton, New Zealand, and 24 pups were subsequently born, of which 20 survived.…”

“…Eight months post release all bats recaptured exhibited signs of disease affecting the ear pinnae and, in some, this was accompanied by hair loss. This was treated but recurred and, because the cause of this disease was unknown, the bats were considered unsuitable for permanent release (Ruffell & Parsons, ). As a consequence, 13 animals were transferred in 2007 to the permanent care of the Auckland Zoo, currently the only holders of lesser short‐tailed bats.…”