Long-tailed bats welcomed by Geraldine landowners

An isolated farm out of Geraldine would be the last place most people would think to look for a newly discovered colony of long-tailed bats.

But that’s exactly where they’ve turned up, and landowners Evan and Clare Chapman are only too thrilled to host their nocturnal guests.

Finding new colonies

Provide caption

After finding out a 400m stretch of old willows were home to a newly-discovered colony of long-tailed bats, the Chapmans were determined to look after the endangered species by fencing off the area.

The Chapmans came close to accidentally destroying the bats’ roost a few months ago, when they decided a group of old willows should be cut down before they fell, potentially breaking fences and crowding out other native plants.

But they remembered a conversation with Orari Temuka Opihi Pareora (OTOP) Water Zone Committee member Lucy Miller, who mentioned long-tailed bats tend to roost in old willows.

Evan contacted Environment Canterbury in Timaru to see what could be done about testing the area, and biodiversity officer Rob Carson-Iles was dispatched to the farm.

Armed with half a dozen automatic bat detectors, Carson-Iles and his team placed the sound sensors along a 400m stretch of the willows and left them for six weeks.

Evan said he was surprised to learn the bats were so close to home and was pleased he had thought to ask Environment Canterbury.

“We already knew there were colonies of bats not too far from here in the Kakahu and Hanging Rock valleys.

“The detectors found that we may have an entirely separate colony of bats on our property, which was pretty exciting. They were too far away from the other sites, 5 or 6km away, to be the same colonies, he (Carson-Iles) thought,” Evan said.

Protecting bat habitat

Weighing in at just 9 grams – the same as a $2 coin – the bats eat insects on the wing, meaning they are flying when they catch them, pulling them out of trees.

With a conservation status of nationally critical, the mouse-sized bats are in the same league as the likes of kākāpō, kōtuku (white heron) and Maui’s dolphin.

Long-tailed bats can fly up to 60km/h and cover tens of kilometres a night, eating up to a quarter of their body weight in that time.

Carson-Iles said the bats are usually found in Fiordland, where their numbers are greater. But there are seven known colonies in South Canterbury too.

“Up here they are living shorter lifespans for a variety of reasons. They are threatened by predators such as cats, possums and stoats.

“As well as that they change roosts every two or three nights, so they’re always on the move but will come back to their roosts around the same time every year,” he said.

When asked what he thought about what effect the bats might have on his farm, Evan said he was emphatic about protecting the threatened species’ roost.

“In terms of our farming operation, it doesn’t really affect anything having them here. The trees are just big and old and would have fallen down, but they could have been roosting there for a while and we would have never known.

“Either way it seems to be a permanent spot for them, so we’re pretty motivated now to keep that habitat safe for them,” he said.

Funding to protect the bats

Another upshot from Carson-Iles’ visit was a deputation to the OTOP Water Zone Committee to see if funding could be sought to protect the bats and their long-term future.

And in the committee’s August meeting it was decided $1800 of Immediate Steps biodiversity funding would be allocated to the Chapmans to help with fencing and re-planting costs.

“With this funding, we can keep stock out with some fencing, as well as planting some natives which could be tōtara, kanuka or cabbage trees,” Evan said.

“That’ll help the bats too as their prey likes to live in those type of trees. We’re part of a farmers’ discussion group and we’ll be passing on this information to them, with the hopes that perhaps they will in turn check their properties for bat habitats. We probably won’t be able to get the fencing underway until about autumn, so maybe March-April time,” Evan said.

Carson-Iles said it was an easy decision for the committee to back a project like this.

“The bats are a priority in the Zone Implementation Programme Addendum (ZIPA) and are a unique animal so they’re pretty special to this area.

“Getting more public knowledge out there is great, and the more people we have out there like the Chapmans, the better really,” he said.