Long-tailed bats keep low profile in west Auckland stakeout

Ever thrown a party and the guest of honour just didn't show?

Then spare a thought for Ben the Batman. No, not THAT Ben (Affleck), and not THAT Batman.

Auckland Council senior biodiversity advisor Ben Paris - Twitter handle @NZBatman - looks slightly embarrassed. He's dragged our butts out to the middle of the Waitakere Ranges to show off his pride and joy - a colony of long-tailed bats - but they're nowhere to be seen.

It's just after dusk, the ideal time to spy these rare creatures as they awake from their day's slumber and begin feeding. There are clearly plenty of insects, especially mosquitos, available for supper this night.

Here at Cascade Kauri Park - between the second and third holes of the Waitakere Golf Course - is usually the best spot to see them. But not tonight, apparently.

Mr Paris has spent the past 30 minutes hopefully tracing the treeline with his bat detector, which resembles a small transistor radio and converts the bat sounds we can't hear into sounds we can hear. Ideally, the device would emit a series of clicks that gradually merge together into a "feeding buzz".

"It's about now I start getting nervous," he admits. "But then they will suddenly appear."

Except this time, they don't.

Mr Paris warned us beforehand there was a 70 to 80 percent chance of finding our quarry, so this was clearly one of those uncommon off-nights.

Eventually, light deserts us and the hunt is over. As we pack up, there's a nagging fear none of us is prepared to verbalise. What if some gruesome fate has befallen this particular colony?

Much of Mr Paris' work is aimed at raising awareness of this endangered species and, ultimately, driving up population numbers.

While relatively common in the bush out west, they are rarely seen in urban areas of Auckland - until recently. Restoration work on streams around Henderson and Swanson has improved the local ecosystem, luring the bats out of the hills and into the city. They've even been found on the fringes of the Auckland Botanic Gardens in Manurewa.

"They may be more widespread," says Mr Paris. "We've found them in Hamilton, flying up and down the Waikato River, and there are places in the South Island where they're found in rural landscapes and willow trees.

Long-tailed bat
When they turn up, this is what a long-tailed bat looks like. Photo credit: DOC/Colin O'Donnel

"The more we look for them, the more we seem to find them in unusual places."

But they're extremely vulnerable to pests - dogs, cats, possums, stoats, even moreporks; and tend to group together according to sex - males at the bachelor pad and females in the maternity roost.

If a predator strikes one of these groups, it can wipe out an entire sex and quickly undermine the breeding programme. Seven years ago, one stray cat killed more than 100 bats on the southern slopes of Ruapehu over the course of a week.

"Let's just say Gareth Morgan may have a point," quips Mr Paris.

Could this explain our unsuccessful bat hunt?

"If it were anywhere else, I might be worried," he insists. "But there's lots of pest control going on here, unless a rogue stoat has passed through.

"Maybe it was a bit chilly for them or they simply flew off in the other direction - it's hard to predict."

Movies have helped make bats one of the most mysterious and feared creatures in mythology, even if much of that perception is ill-founded.

"I think bats are really misunderstood," says Mr Paris. "Hollywood has done a lot to damage their reputation.

"They won't fly into your hair; they won't suck your blood. These bats are just part of the natural New Zealand landscape."

They're small - about the size of your thumb - with a wingspan about as wide as your hand. They look more like a fantail than Count Dracula, which is perhaps why reported sightings are rare.

But their reputation has made bats very popular among the public, especially children.

Every January, on Monday, Wednesday and Friday each week, Mr Paris leads excursions into the bush - just like this one - to search for bats. They usually book out far in advance and bookings open for 2018 on December 1.

Auckland Council is desperate to enlist the help of local residents to help monitor the spread of these long-tailed bats, and has offered the use of detectors for that purpose. That programme, sponsored by the Waitakere Ranges Local Board, is already oversubscribed, with 50 people on the waiting list.

If these little critters are out there, they will surely be found.

Better luck next time, Batman Ben.