Hamilton's native bats
Hamilton city is one of the only cities in New Zealand to still support a resident population of long-tailed bats.
The long-tailed bat is unique to New Zealand, and is one of our only two remaining species of native terrestrial mammals. These bats can be found throughout New Zealand in varying habitats, but its numbers are declining due to the removal of trees (where bats roost), predation by pest mammals, and increasing competition for roost sites from rats and possums.
Long-tailed bats are capable of long distance flight. These bats may have large home ranges and regularly move between forest fragments to feed and roost. There are a few confirmed bat roosting sites in the southern part of the city, but bats are likely to be more widely distributed throughout the city than previously thought.
- Dark brown to black fur.
Long-tailed bat. Image courtesy of Gerard Kelly.
- Limbs and membranes virtually hairless.
- Small, weighing 8-14g with a wingspan of about 25cm.
- Feed on flying insects like moths, beetles, mayflies, midges and mosquitoes.
- Breeding females give birth to one pup per year and carry juveniles during feeding flights until they reach adolescence at around 4-6 weeks.
- Use echolocation to identify food and other objects while flying.
- Rest by day and feed by night.
- Roost in small cavities in old or large trees, including dead trees.
- Frequently switch roosts.
- Hang upside down and hold onto roost with claws of one or both feet.
- Social animals, with sometimes between 10 to 50 bats roosting and feeding together.
- Can fly long distances and may have large home ranges.
- Regularly move between forest fragments to feed and roost.
- During the breeding season, may separate into male and female colonies.
- Habitat loss.
- Competition for roosting sites from possums and rates.
- Predation by feral cats, stoats and rats.
If you have seen a long-tailed bat in Hamilton (or detected one with a bat detector), we’d love to hear from you so we can keep track of bat distribution across the city. Tell us where and when you saw your bat, by filling in our enquiry form.
View a map of Hamilton bat sightings here.
Because bats rest during the day, they are often unseen by humans. Bat detectors can be used to monitor bat sounds that can’t be heard by the human ear.
If you think there may be bats living on your property or in a nearby park, you can borrow a bat detector and check it out for yourself. Bat detectors can be borrowed free of charge. Give us a ring on 0800 800 402 for more information.
Below are two audio files of the sounds of the bat detectors in action when a bat is nearby. The waveform graphs below them show what the sounds 'look like' in our equipment.
Bat detector soundclip 1 (single long-tailed bat search phase ecolocation pulse at 40Khz)
Bat detector soundclip 2 (multiple long tailed bats flying and ecolocating together)
|Crown Copyright: Department of Conservation Te Papa Atawhai (August 1973), Photographer: J. L. Kendrick|
You can help by protecting standing dead trees and old-age trees with cavities, which are the natural habitat of long-tailed bats. Dead trees and old trees with hollows and cavities are still valuable for wildlife!
You could also consider planting large trees for future bat generations.
Bats move to a new roost tree regularly so are not always present at a site. If you think bats might be present on your property, or you’re about to remove a large or dead tree contact Waikato Regional Council.
Project Echo aims to gather information on bat distribution throughout Hamilton city. This project could lead to on-going work to protect bat roosting trees and provide predator control.
Waikato Regional Council, Hamilton City Council and the Riverlea Environment Society Inc. (RESI) are the project partners. A number of other organistions also get involved in different aspects of the project.
Find out more about the project in this video clip:
You can download these publications containing facts and tips about bats and Project Echo:
- You can keep up-to-date with what's happening with the project by visiting Project Echo's Facebook page.
- You can also visit the Riverlea Environment Society Inc (RESI) web page.