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1 March 2019 Farah Qoulaq

Today marks World Wildlife Day and an opportunity to dig deeper into the work WSP Opus is doing to help preserve New Zealand’s threatened species and their habitat to ensure that these exist for our future generations.

For Ecologist Caitlin Dodunski, her work at WSP Opus has offered the opportunity to work closely with New Zealand’s native land mammal – the endangered long-tailed bat.

WSP Opus is paving the way in bat surveying techniques in New Zealand through the innovative use of thermal imaging. This exciting technology is allowing us to collect high-quality data on how bats use their landscape, their commuting routes plus, their behaviour with large infrastructure projects.

The thermograph below shows a pekapeka-tou-roa / long tailed-bat (Chalinolobus tuberculatus). This long tailed-bat has the highest national threat ranking; currently listed as threatened - nationally critical.

 thermal imaging

The species can fly at 60km/hr and has a very large range, over 100km2. They regularly move between roosts every night, as they require different conditions at different times of the year.

Although the New Zealand native long-tailed bat is one of only two native land mammals (the other is the short-tailed bat), not a lot is known about them.

One of 15 species, the long-tailed bat is considered a micro-mammal – fitting into the palm of a hand. They hunt by hawking and have a diet of insects such as flies, moths and beetles.

Unfortunately, the long-tailed bat is classed as “nationally critical’ and is in danger of extinction if nothing is done to reverse the population decline.

Fast facts

  • The Māori name for bats is pekapeka
  • Pekapeka have bodies the size of a person’s thumb (5-6cm) and a wingspan of nearly 30cm
  • New Zealand pekapeka were once numerous and widespread, but human settlement has had a drastic impact on the population
  • They can fly up to 35km in a night and at a speed of 60km per hour.
  • An aerial insectivore, bats feed on small moths, midges, mosquitoes and beetles
  • Pekapeka are believed to produce only one offspring each year

For Caitlin, fieldwork presents a varied work schedule and opportunities to trial new techniques.

“My typical week in the summer includes deploying acoustic bat monitors as part of annual monitoring to meet consent conditions for the Waikato Expressway including Hamilton, Huntly and Cambridge sections.”

Caitlin also carries out behavioural monitoring of long-tailed bats using a thermal imaging camera to assess any impacts of the construction of the expressway on their behaviour. This involves a lot of summer night work as the bats are active after dusk.

However, in the winter when the bats aren’t as active her focus turns to the data collected from the acoustic monitors over the summer and writing the relative monitoring reports.”

“Another big part of my job is to make sure that no bats are roosting in trees before they get cut down for construction of the road. I do this by assessing individual trees for roosting potential, as well as acoustic monitoring and watching the tree at dusk and dawn to see if bats are roosting within them.”

Caitlin says that a lot of people aren’t aware that there are bats in New Zealand – let alone that we have a native species. She finds this a great conversation starter and enjoys helping share information about these tiny, but precious animals.

“The first time I finally saw a bat after working with them for over two years was very exciting, we got to trap them out the back of Piopio to handle and band them. It made me appreciate that the work I have been doing is for a good cause.”