Mystacinidae

Introduced mammalian predators, in particular rats (Rattus spp.), are a major threat to New Zealand bat populations. Aerial application of the toxin sodium monofluoroacetate (1080) is currently the most costeffective method of controlling rats across large spatial extents. Lesser short-tailed bats (Mystacina tuberculata) may be vulnerable to secondary poisoning from 1080 because they feed on invertebrate prey on the ground that may have consumed toxic bait.

The lesser short-tailed bat (Mystacina t. tuberculata) has been found in 18 locations in indigenous forest in North Island since 1961, mainly in Northland kauri forest (including Little Barrier Island), on the volcanic plateau (including Tongariro National Park), Urewera National Park and in Tararua Range. In South Island this bat has only been reported once since 1961, in North West Nelson Forest Park, and must be regarded as endangered. It is present also on Codfish Island, but is thought to have become extinct on Big South Cape and Solomon Islands about 1967.

Introduced mammalian predators are a major threat to New Zealand’s wildlife, including bats. Controlling these predators using traps and poison baits can reduce their impact on bat populations. However, lesser short-tailed bats (Mystacina tuberculata) are potentially susceptible to toxins used for pest control in New Zealand forests because of their broad diet and habit of feeding on the ground. Therefore, the risk of secondary poisoning should always be assessed before new toxins are used in areas inhabited by lesser short-tailed bats.