Lesser Short-tailed Bat (Mystacina tuberculata)
Kapiti Island (1965 ha, off SW of North Island). In April 2005, 20 captive-bred lesser short-tailed bats were released onto Kapiti Island. It is hoped that this will be the world’s first successful translocation of bats. Previous attempts at translocating adult bats (pekapeka) were unsuccessful, possibly because bats returned to their source populations. Consequently, young juveniles were used for the reintroduction to Kapiti. The juveniles were produced by pregnant females collected from an isolated, genetically-distinct, threatened colony in the Tararua Forest Park in December 2004 and taken to the Pukaha Mount Bruce National Wildlife Centre in the Wairarapa to give birth. In February, when the pups were old enough to fly, they were transferred to Kapiti Island where they were placed in a temporary aviary to acclimatise to the island before being released into the wild. The pups’mothers were returned to their home in the Tararuas. Supplementary feeding was stopped in September, and bats caught in October had maintained their weight. The bats were roosting in tree crevices rather than the nesting boxes provided for them, but still visited the aviary where they were initially kept and snuggled into the polar fleece where they roosted there. Bats caught in December 2005 showed balding and had scabs on their ears, and these were probably clinical signs of a mite infestation. No mites were seen on the bats or in skin scrapings, but they are usually present at low densities and difficult to diagnose except based on clinical signs. Infestations in captive populations tend to lead to death, so bats were treated. Bats caught at this time showed a slight loss of weight, but were similar to weights from natural populations. Infestation may have occurred either because (1) bats were in poor condition and had low immunocompetence, or (2) bats frequently roosted in the aviary provided and did not show the roost switching behaviour seen in natural populations. More juvenile bats were scheduled for translocation to Kapiti Island in 2006. Contact Lynn Adams.