It’s been known for a while that long-tailed bats live around Gordonton, but a new study is showing just how widespread they are in the district.
Waikato University student Olivia Dixon has found evidence of the critically endangered endemic species, in the northern areas of Hamilton. Ms Dixon initially surveyed around the northern edge of the city, within a 5km buffer, but then expanded to include the Hakarimata Ranges and kahikatea patches around Gordonton.
No comprehensive surveys had been previously undertaken across the whole northern area of Hamilton.
Hamilton is one of the only cities in New Zealand with an urban population of bats, with southern Hamilton a known hotspot for them, where they tend to roost in the semi-rural habitats on the edge of the city and have large home ranges across the area.
Through the survey, she found bats present in the north and west of the city, albeit in lower numbers compared to the south. Some hotspots included the kahikatea patches around Taylor/Sainsbury Road area, as well as confirming their presence in the Hakarimata Ranges.
“It was exciting to see patterns in bat activity arising the more sites I surveyed – there was never a dull moment.”
To survey the bats, she spent a few weeks using a recorder that detects the bat’s echo location calls.
Kate Richardson, a community restoration advisor with the Regional Council, said there’s still more to know about urban bats as most research has been done in native forests.
“They’re really threatened by habitat loss, as they like to roost in both native and exotic trees which people sometimes chop down without realising they’re impacting the bats. Bats are also preyed upon by rats and stoats,” she said.
Further research planned
Summer is a good time to research bats as they tend to be more active, emerging at dusk and returning to their roosts at dawn.
“One thing we’ve found out about Hamilton bats is that they tend to stay in their roosts longer, whereas in other locations like Fiordland they might change every night. This is probably because there are less roosts available to them in Hamilton compared with places like Fiordland.”
The university is planning further bat research projects, with an upcoming PhD student looking into lighting and its effects on bat behaviour, including roading developments, in terms of how they feed and roost.
“As our cities expand, we’re only going to come into more conflict with wildlife, so it’s important we understand the interactions and support those remaining populations like the long-tailed bats,” says Waikato University’s Dr Clare Browne.
Bat-geeks want to know more!
Ecologist Wiea van der Zwan, who took the photos of the long-tailed bats on this story, says there are hopes to track Waikato bats in the future.
“We know (more or less) what is happening with southern Hamilton bats, but with more studies done now in the North, a whole new range of questions came up and us bat-geeks are keen to know where they come from and who they relate to!”
The bat with the radio transmitter on its back was part of a study she was involved in a few years ago.
For landowners who would like to take action to protect any bats that might be on their property, it’s important to focus on predator control (rats, mustelids, feral cats) and habitat protection.
Bats are known to roost in both native and exotic trees including kahikatea, black locust/false acacia, Tasmanian blackwood, oak, eucalyptus, grey and crack willow, London plane, pine, birch, casuarina and macrocarpa, so protecting current roost trees are vital.