Long-tailed Bat Research in the Hūnua Ranges

Our commitment to service learning through research gives our semester students the opportunity to work on intensive directed research projects for four to five weeks as part of their fifteen-week program. All EcoQuest research programs have scientific and societal relevance, and EcoQuest has long-standing relationships with a large number of stakeholders. This semester, we have six projects running, in locations as far afield as Whangapoua in the Far North, to Maungatautari in the mid-Waikato. We have two projects located in the Hūnua Ranges, including our bat project...

 

The team of researchers collecting data on bat habitat.

Last September, EcoQuest was fortunate to receive a grant from the U.S. Embassy and Consulate in New Zealand, to begin research on one of New Zealand’s endemic species – the long-tailed bat (pekapeka tou roa, Chalinolobus tuberculatus). Long -tailed bats are one of only two remaining species of bat in New Zealand, the other being the lesser short-tailed bat. These two bat species are the only native terrestrial mammals in New Zealand, and they are rarely seen, heard, or talked about. The status of long-tailed bats the North Island has just recently been changed from ‘Nationally Vulnerable’ to ‘Threatened – Nationally Critical’, a status of more serious conservation concern. Our goal is to establish a long-term monitoring program for selected populations of the elusive long-tailed bat, pekapeka tou roa, so that we can learn more about their abundance, the location of their roost sites, and where they travel to feed each night.

 A long-tailed bat in the Eglinton Valley in Fiordland National Park, New Zealand (Department of Conservation project).

The EcoQuest Field Centre is nestled at the base of the Hūnua Ranges on the coast of Tikapa Moana the Firth of Thames, making it the perfect location for research projects in Hūnua Regional Park. The Hūnua Ranges are one of the main known hotspots for long-tailed bats in our region, and we began our second round of research on this important species last week. Four EcoQuest students, Emily Dutton, Doris Zhang, Morgan Schwartz and Emily Dunleavy, kicked off ten days of bat monitoring with a successful evening at Waharau, our local Regional Park, only a five-minute drive down the road from EcoQuest. We were lucky enough to be standing on the edge of a clearing, where a bat was feeding on moths up above us. “It was just an incredible experience hearing them and actually spotting them in the sky,” said Doris.

Emily Dutton and Doris Zhang searching for bats in the Hūnua Ranges, using a red light so they don’t scare away their research subjects.

Through the U.S. Embassy funding, EcoQuest was able to purchase hand-held heterodyne bat detectors, which convert a bat’s echolocation call to a sound that we can hear when it passes within approximately thirty metres of the detector. This means we can record the presence and absence of long-tailed bats along one-kilometre walking transects in different sites throughout the Hūnua Ranges and surrounding areas. Walking through the New Zealand forest at night with a bat detector is a unique experience, reflects Morgan. “You’re up close and personal with the darkness. There’s stars, and possums, and hedgehogs, and glow-worms, and ruru (morepork). It’s dark, and there’s a lot of static from the machine, but you just keep your hopes up that you’re going to hear a bat… you’re just always brimming with anticipation.” Morgan has found her research thus far to be different from her usual studies, as “this is actual feet on the ground, full-on experience, and that’s awesome, especially as an undergraduate.”

Morgan Schwartz hangs up an automatic bat monitor to record the echolocation calls of bats flying past at night.

Our team has also been recording long-tailed bat activity with another, less physically demanding method. We placed fourteen automatic bat monitors (ABM’s) out in various sites, six on private properties and eight in Hūnua Regional Park. These bat monitors are programmed to turn on automatically at dusk, and passively record the echolocation calls of any bats passing by them during the night. The monitors then automatically switch off just after sunrise, shortly after the bats have returned to their roost sites. These ABM’s are left out for nine consecutive evenings, allowing students to determine the presence and activity of bats at each of these fixed monitoring sites during that period. Detailed analysis of the spectrograms (visual depictions of the echolocation calls) created by these devices can also yield further valuable information, including feeding indicators which give an insight into the foraging activity of the bats. During last year’s monitoring efforts with eleven of these devices, we recorded 2,243 bat passes over ten nights, which was a huge success. We are collecting the final data for this semester’s survey at the end of the week, and we are hopeful that our monitors will have recorded even more bat activity this time around.

Automatic bat monitors record bat echolocation, which they use to navigate and forage for prey.

So, what do our team of researchers hope to achieve for our local bat population? Emily Dunleavy is positive about the future: “Studying long-tailed bats here in New Zealand has been quite the honour, they’re often a forgotten species here in New Zealand, so to have the privilege to go out in to field and hear them – and even get to see them – not too far from EcoQuest, has been amazing. The more research that we do on presence and absence data, the more conservation funding can be allocated to the long-tailed bat, the better we can protect them. Hopefully this bat will no longer be an unknown species to the public, and people will realise that they’re living in their backyard.” We look forward to sharing our findings with the local community, the private land owners who have kindly let us place these monitors on their land, iwi, the science community and the wider public, in the hope that this important work can be continued and expanded upon in the future.

Morgan Schwartz, Emily Dutton, Elicia Milne, Emily Dunleavy and Doris Zhang ready for an evening of bat research.

A special thanks to Dr David Clarke, the academic supervisor for this project, the U.S. Embassy for their ongoing support, and to the private landowners who have granted us access to their beautiful backyards to enable us to carry out this research.

Thank you to the property owners who have allowed us to place automatic bat monitors their land on the edges of the Hūnua Ranges. 

Blog and photos by Elicia Milne.