The Transport Agency plans to fill in roosts of long-tail bats along the proposed route of the Mt Messenger bypass on State Highway 3, in an effort to force the critically-endangered mammals to relocate.
The controversial practice falls outside the scope of Waka Kotahi's application for a Wildlife Act permit which allows for the incidental killing and collection of bats, lizards, kiwi and other creatures in the way of the development.
Transport Agency contractors have recently been inspecting the proposed route in the King Country looking for bats and lizards while final appeals against the $280 million project make their way through the courts.
Poutama Charitable Trust and farmers Debbie and Tony Pascoe oppose the project, which is on the main route in and out of Taranaki from the north and crosses the Pascoe's Mangapekepeke Valley property.
Trust spokesperson Marie Gibbs said contractors told them they were going onto the land with the intention of filling in bat roosts, so the trust quizzed the Department of Conservation (DOC) about it.
"We asked them if they knew anything about NZTA being in that valley blocking up bat roosts and we also asked them if they knew anything about that practice in general and whether that would be happening and we never got any response."
A subsequent request under the Official Information Act revealed plans to fill in bat roosts, including cracks, holes and crevices that could potentially be used as roosts, former roost sites and remove epiphytes from trees, where bats were also know to roost in.
Tony Pascoe says the Mt Messenger bypass project will be damaging to wildlife and the valley, and ruin wetlands at Mangapēpeke Valley. Photo / RNZ
Gibbs said Poutama and the Pascoes feared the bats would be blocked off in the lead up to winter leaving the critically-endangered mammals vulnerable.
"The feedback we've had from other ecologists is that they would be very interested to know whether NZTA had been in there blocking off bat roosts because they were unaware of that as an acceptable practice."
Ben Paris - aka the New Zealand Batman - is an Auckland City Council ecologist and bat enthusiast.
Blocking up roosts was a relatively new practice and one that divided opinion, he said.
"It's kind of an ethical dilemma I believe, where you know, we may not be disturbing the bats but it may seem a little bit rude for the bats to come home from a night of feeding and find that their front door is completely locked."
Long-tail bats moved roost quite often, but trees suitable for roosting were in short supply.
DOC Taranaki operations manager Gareth Hopkins said Waka Kotahi's application for a Wildlife Act permit was still being processed. While it covered incidental killing and collection of animals it did not allow bats to be disturbed by blocking up roosts.
"Recent case law has determined DOC cannot authorise disturbance of bats or their roosts. In essence, DOC does not have a legal mechanism to allow or refuse what Waka Kotahi proposes in relation to bats at this site."
Ironically, a Wildlife Act permit covering the incidental death of bats could allow Waka Kotahi to simply cut down roost trees when bats leave at night of their own accord.
Paris said this had become common practice and he was not happy about it either.
"My preference would be to try and avoid the bat habitat at all costs. Bat roosts are one of the limiting factors for bats and a very good roost tree is very hard to find and sometimes it's those very old growth trees that they use and you can't replace them very easily."
Tony and Debbie Pascoe are going to the high court to challenge the Mt Messenger bypass project at Mangapēpeke Valley. Photo / RNZ
Waka Kotahi director regional relationships Linda Stewart said its inspection teams found no bats or bat roosts in the Mangapekepeke Valley and no sites suitable for bats were filled in.
But it was still on the cards.
"We will not take any action to prevent bats from roosting in trees until the project begins in earnest. When we are able to begin construction we will fill potential or established roost areas in trees that are going to be felled as part of the project. Our goal will be to protect the bats by diverting them to trees that will not be affected by our activities."
Stewart said the Mt Messenger bypass project involved a massive habitat restoration component and that combined with ongoing predator control meant there would be a net gain in biodiversity in the area after the road was completed.
Pending court appeals, construction was earmarked to begin in September next year.
