Waikato building developments putting native bats at risk

By Jessica Tyson

Conservation organisation Forest & Bird are calling for better protection of pekapeka, rare native bats in Hamilton “before they disappear from the region”.

Forest & Bird central North Island regional manager Dr Rebecca Stirnemann says new developments are wiping out long-tailed bat habitats and Waikato Regional Council and Hamilton City Council urgently need a long term strategy to make sure long-tailed bats are not lost.

“Long-tailed bats are critically affected by development that squeezes them out - and they are on the brink of extinction in Hamilton," Dr Stirnemann says.

She says authorities have known bats are living in Hamilton for about 15 years, but there is still no strategic plan to protect their habitats and flying routes.

“We can see they are no longer using half the city because new development has cut off their access routes. Hamilton City Council needs to look at the cumulative effects on bats of all the new developments - all the housing subdivisions, the industrial expansion and the road projects.”

Both Waikato Regional Council and Hamilton City Council, alongside the Riverlea Environmental Society Inc, run Project Echo which aims to gather information on bat distribution throughout Hamilton.

Team Leader of the Natural Heritage at Waikato Regional Council Amy Satterfield says, "Some of that work is bringing the University of Waikato do to some research, some monitoring to understand what each of those different roosting areas are because that information can then feed and inform a management plan to give us that bigger picture."

A 2017-2018 survey prepared for Project Echo found bat activity to be mostly confined to the southern fringes of the Hamilton city, where there is less urban development.

“However, development has now commenced in these areas, including the construction of the Hamilton Section of the Waikato Expressway, and the planned development of subdivisions and roads in close vicinity to the Mangakōtukutuku gully system and Waikato River margins, results from the survey said. 

"While the scale of the effect of these developments on bats is unknown, the cumulative effect of these developments on the main bat habitats will likely have an adverse effect on the long-tailed bat population present in Hamilton City."

The survey says effective strategies are required to protect and enhance known roosting, commuting corridors and foraging areas.

About Pekapeka (Long-tailed bats)

Long-tailed bats have the highest threat ranking of ‘nationally critical’ and are in decline across the country, because of habitat loss. Hamilton is one of the only cities in New Zealand where long-tailed bats survive.

Bats need mature trees with cavities to roost and nest in, and natural spaces, such as deep gullies and waterways, where the insects they eat can flourish. The dark-loving creatures need areas without too much artificial light and without high noise levels, because they navigate using echo-location.

Cats, possums, stoats and rats prey on bats, reducing their numbers faster than they can breed, as females usually only raise one offspring a year.

“Bats are New Zealand’s only native land-based mammals. These little brown creatures weigh about 10 grams, but they can fly at 60 kilometres an hour and have huge home ranges, of up to 100 square kilometres, says Dr Stirnemann. 

“The unique characteristics of bats make them harder to protect – and that makes it more important that every agency and council is doing its bit to look after them."

Forest & Bird has been granted $5000 from the Len Reynolds Trust for research on long-tailed bats in the Waikato.

This research will focus on the best ways to improve the chances of bats surviving in the face of development.

Hamilton residents can help bats survive by keeping native forest and mature trees on their properties, by carrying out pest control, by reducing pesticide use so bats have plenty of insects to eat, and by reducing light pollution from lighting outside their homes, Dr Stirnemann says.