Bats rule roost in new city suburb of Peacocke

Friday, 23 August 2024

Hamilton's gone bats over the new Peacocke bridge.

Hamilton’s about to get as bat friendly as Gotham City.

Work is in full swing as Hamilton City Council makes sure our smallest native mammal and the bat highway they use isn’t disrupted by the city’s largest investment in infrastructure.

South Hamilton is home to the critically threatened long tail bat pekapeka-tou-roa, and when the new multi million dollar bridge connecting the city to the Peacocke residential development was being built the council wanted to make sure they didn’t disrupt their flight plan.

Council’s Technical Director Planning Infrastructure Nathanael Savage said with the bridge they’ve created a concept they call the “hop over and the hop under ”. It encourages bats to go either side of the bridge when flying down the river.

It meant that selecting what to plant was crucial.

Hamilton City Council’s Andrew Parsons and Nathanael Savage checking the bat boxes along in south Hamilton.

“Particularly when trying to maintain that space underneath [the bridge], it shouldn't grow tall because then it starts to fill up that space. Whereas up on the bank, when you want them to fly over the carriageway, they need to be a decent height.”

Savage said high and fast growing vegetation is best as thermal imaging shows the bats tend to fly at or above the canopy.

“It's all about making sure we're not severing that connectivity for their flight paths by something they don't like, that it forces them to turn away, and go somewhere else.”

Lighting is another important factor for the bridge and suburb, with special street lights put in and also a warm tone bulb used.

An adult long-tailed bat only weighs between 8 and 11grams (file photo).

But it’s not just the bridge area which ensures the bats thrive.

With eventually 20,000-odd people residing in the suburb getting homes, the bats have also entered into the housing market with roosts put up in surrounding areas as part of the council’s largest environmental investment.

“There are 80 bat boxes, which have predator bands around the tree trunks on either side of the boxes. Around 41% of the boxes have signs of being used, which is a pleasant surprise,” Savage said.

There are still another 20 boxes in this financial year to be installed.

The bat boxes which the tiny mammals use to roost around the city.

The council have spent a lot of time monitoring the pekapeka-tou-roa with acoustic or radio tracking to understand where they fly and find food.

The council also has more than 15 hectares of gully restoration work, which includes planting, ensuring trees suit the local conditions and needs of existing wildlife.

The new bridge has compensated for the bats flight path with warm street lights, and planting which encourages bats to go over or under the bridge.

There has also been pest and predator control implemented to protect the planting, the bats, lizards and birds.

It’s not just the bats which have got new homes but copper skinks have also been catered for.

Savage said if construction was encroaching on their habit they were uplifted to be kept safe and some go to “lizard hotels” which are man-made homes in restoration areas.

“They are either relocated close by if it's suitable, or they go to one of those restoration sites. And those restoration sites have got predator control underway, so traps for possums, rats, mice, as well as occasional poisons.”

People will get their first look at that bridge and surrounds at an open day on August 31, between 10am -2pm.

An exact time and date of the bridge opening to traffic will not be announced to manage traffic on the wider network and ensure public safety.