Long-tailed bat

Threats

Long-tailed bats were common throughout New Zealand in the 1800s, although by 1900–1930 they were becoming scarce in many districts.

Surveys over the last 10–20 years indicate South Island long-tailed bats are rarer than previously thought. They were once common in Dunedin, Invercargill and Christchurch, where they roosted under the wooden bridges across the Avon River until 1885.

Causes of their decline are combinations of:

• clearance and logging of lowland forests
• cutting of old-age trees for firewood
• clearance of trees for urban expansion and agricultural intensification
• predation by introduced animals such as cats, possums, rats and stoats
• exclusion of bats from roosts by introduced mammals, birds, wasps and human interference.

Facts

The long-tailed bat (Chalinolobus tuberculatus) belongs to a widespread family and is closely related to five other species of wattled or lobe-lipped bats in Australia and elsewhere.

Long-tailed bats from the North Island and South Island were confirmed in 2018 as one species. It has the highest threat ranking of Nationally Critical.

Long-tailed bats are widely distributed throughout mainland New Zealand, Stewart Island, Little Barrier and Great Barrier islands and Kapiti Island. They are more commonly seen than short-tailed bats as they fly at dusk along forest edges and because some populations have persisted in urban and rural landscapes.

• Long-tailed bats are smaller than the short-tailed bat, chestnut brown in colour, have small ears and weigh 8–11 grams.
• They are believed to produce only one offspring each year.
• Their echo-location calls include a relatively low frequency component which can be heard by some people, though most calls are at a frequency of 40 kHz which is higher than people can hear.
• They can fly at 60 kmph and a bat colony can have a range of more than 100 km².
• An aerial insectivore, they feed on small moths, midges, mosquitoes and beetles.

Canterbury long-tailed bat

South Canterbury supports the only known long-tailed bat population on the east coast of the South Island. Bats are limited to a small area from Peel Forest in the north, southwards through the foothill gorges of the Orari, Waihi, and Te Moana Rivers, Geraldine, and the Kakahu and Ōpihi Rivers.

On the willow-lined Ōpihi, bats have been reported regularly from Arowhenua and inland to the gullies of The Brothers and to the Opuha Gorge. The core of the population is centred on forest remnants and limestone areas around Hanging Rock.

Geraldine is one of the few towns in New Zealand where it is possible to see long-tailed bats. They flit like large butterflies at dusk as they emerge from giant totara and mataī in Talbot Forest.

Our work

Surveys are being undertaken in many areas to determine the current distribution of the two bat species. Bats are located by searching with electronic bat recorders that can pick up high frequency echo-location calls.

DOC protects priority populations of long-tailed bats through predator control. In the Eglinton Valley in Fiordland, the population of long-tailed bats has steadily increased over more than a decade as a result of sustained predator control work there.

Research has revealed the complex social systems of short-tailed and long-tailed bats, with both bats using a series of communal and solitary day-time roosts.

DOC’s National Predator Control Programme is essential to recover bat populations in our forests.

Bats are monitored at several places throughout New Zealand to inform and refine how pest management can protect bats.

The DOC Electronics team developed the “AR4” bat recorder, now widely used in NZ to survey for bats. DOC also administers a national database of bat records so we can learn more about bat distribution and how that changes over time.

Long-tailed bats along the Kepler Track

Read about the discovery of long-tailed bats along the Kepler Track Great Walk and plans for their protection. Kepler bat research report (PDF, 5,920K)

How you can help

Protect forests and trees

Protect native forest in your area. This will assist other species as well as bats.

Retain standing dead trees and old-age trees with cavities. Dead trees and old trees with hollows and cavities are still valuable for wildlife. Bats rest by day and breed in cavities in old-aged trees. They move to a new roost tree regularly so are not always present at a site but may return later to reuse it.

Protect cabbage trees and other lone native trees on farmland. Hollows in cabbage trees are also important roosts. Replant natives in these areas to shelter the trees and ensure their long-term survival.

Protect old-age willow and poplar forest around ponds where bats feed. Bats like to feed on aquatic insects over water. Ponds sheltered by overhanging trees help bats to feed in poor weather.

A social bat group can use more than 100 different roosting trees. If woodlots are being felled, check trees for cavities first. Ask DOC for assistance in determining how they might be safeguarded.

Look out for bats in your area

If you are a backcountry user, farmer, or belong to a conservation group, become involved in bat spotting to assist DOC in determining bat distribution throughout New Zealand.

Where you find bats, do not disturb them. It is safe to watch bats as they emerge from roosts or feed, but sit quietly so they will not be frightened away.

Some bats in South Canterbury roost in limestone bluffs in late summer and winter, so rock climbers need to be careful not to disturb them.

Reduce use of pesticides. An increase in bat numbers will compensate for reduced pesticide use.

Keep your cat inside at night, or consider not owning a cat. Cats regularly kill long-tailed bats.