7 Nov 2013

Urban Bats in Auckland

From Our Changing World, 9:46 pm on 7 November 2013



Auckland Council biodiversity advisor Ben Paris, aka NZ Batman, with one of the bat boxes the council has installed in Swanson Reserve in the hope that they will encourage long-tailed bats to start roosting there. (image: V Meduna)

Few people will have seen New Zealand’s thumb-sized native bats, the country’s only native land mammals. In pre-human times, they darted about the forests in their millions, but today they are reduced to a few scattered groups.

There were once three species but the greater short-tailed bat was last seen in the 1960s and is now thought to be extinct. Of the two other species of bat, long-tailed bats, Chalinolobus tuberculatus, are more common than lesser short-tailed bats, Mystacina tuberculata, but they are seldom seen as they emerge from their roosts around dusk to hunt. They feed exclusively on flying insects, form complex social groups and, as research on radio-tagged bats in Fiordland's Eglinton Valley has shown, frequently switch between roosting alone and roosting with a colony.

Worldwide, there are two types of bat: megabats such as fruitbats, which navigate mainly by sight, and microbats, which locate prey using echolocation. New Zealand's bats are microbats. They emit pulses of high-frequency sound and listen for the returning echoes that bounce off objects.

Both lesser short-tailed and long-tailed bats are threatened and in danger of extinction, but long-tailed bats have been found roosting in suburban areas of Auckland. They have been observed feeding at Swanson Reserve, are roosting in the Waitakere Ranges, and the search will be on this summer at Riverhead to find the roosting site of a newly found population.

In this interview, Auckland Council biodiversity advisor Ben Paris (pictured above), perhaps better known as New Zealand Batman, takes Veronika Meduna on a bat-monitoring night walk to explain how people can help the council to detect bats and attract them to their local neighbourhood.

Contact the biodiversity team at Auckland Council on 09 301 0101 or email biodiversity@auckland council.govt.nz for information or to report bat sightings.