Bats' secret home sought
A search is on this summer at Riverhead to find the roosting site of a newly found population of rare bats.
Riverhead, Swanson, and Mt Tamahunga overlooking Pakiri have all turned up as previously unknown sites for populations of long-tailed bats after research by the University of Auckland last summer.
The joint effort by the Auckland Council and the university is expected to be ongoing to find and protect feeding and roosting sites around Auckland for the tiny nocturnal hunter for future modelling.
Activity around the Riverhead Forest particularly was huge each night, council bat expert Ben Paris says. So that's where the effort will go this summer.
Mr Paris is sometimes dubbed "Batman" and gives talks and leads bat walks.
Children often have a fascination with these winged creatures, which Mr Paris helps along by wearing a creepy bat hat when he talks to students.
Getting youngsters' attention is important, as our bat populations are in trouble and we need to find where they are to protect them, he says.
This also sees the council welcoming amateur spotters to borrow their bat detectors to find them. The detectors have a range of about 50 metres.
Bats are the stuff of vampire legends, but our own bats are more of a threat to blood sucking mosquitoes than to us.
Their voracious appetite for small moths, midges, mosquitoes and beetles, which sees them scoff up to 600 insects an hour, also makes them useful as pest control in agriculture and horticulture overseas.
Bats were the only mammals in New Zealand until rats turned up with the first Polynesian settlers.
There were three species and, like our birdlife, they have also fallen victim to introduced pests.
The greater short-tailed bat is already thought to be extinct - last seen in the 1960s. The lesser short-tailed bat and long-tailed are threatened and in danger of extinction. They spend much time on the ground and this puts them at risk from cats.
Finding these fascinating little critters, which have a 100 square kilometre home range, can be a mission as little is known about where particular populations roost.
They have been seen chasing insects attracted to spotlights around some urban buildings and sports fields, but it's unknown if they are established in urban areas. They hunt using echolocation so don't need lighting.
Long-tailed bats only weigh up to 12 grams and can be seen flitting about at dawn and dusk.
They eat and drink while in flight and their erratic behaviour often has people mistaking them for swallows, Mr Paris says.
They can fly at 60kmh and use the airway corridor above waterways to catch insects, also preferring the broad open spaces of golf courses and school fields.
While the bats at Riverhead look to be hunting in and around the forest they may be roosting in a forest pocket about 5km further north, Auckland University Associate Professor Stuart Parsons says.
The animals go into partial hibernation during winter, only feeding sporadically. It's at this time they're the most vulnerable to rats getting into their nests, usually in gnarly old trees or under bark.
A student will be trying to find the exact roosting site this summer so it can be protected. If there's time, university researchers may also check out Puhoi.
"The initial survey will involve automatic sound recorders that pick up the bats' sonar waves, which will tell us where they are and the level of activity," Dr Parsons says.
Contact the biodiversity team at Auckland Council 09 301 0101, email biodiversity@auckland council.govt.nz for information or to report bat sightings.
- © Fairfax NZ News
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