Pekapeka Survey Aotea | Great Barrier Island 

ANNAMARIE CLOUGH  (Auckland Council) with Patrick Stewart (Red Admiral Ecology)

In December 2021 Soundcounts, under contract to Auckland Council, carried out an autonomous ultrasonic survey of pekapeka/New Zealand long tailed bat (Chalinolobus tuberculatus) across Aotea/Great Barrier Island. A taonga species on Aotea, the North Island long tailed bat is presently classified as “Nationally critical”, the highest threat level for native species before extinction in New Zealand(1).  

Northern Catchments

Analysis of hourly time/location data indicated that bats were roosting within the upper reaches of the Kaiaraara catchment, behind Port Fitzroy with the latest activity 45 minutes prior to sunrise. Indications were that bats were not roosting within the Okiwi catchment, the latest activity being 75 minutes prior to sunrise. Bat activity on the road saddle between the Fitzroy and Okiwi catchments was limited to the middle of the night and indicative of them using the road to commute between the Fitzroy and Okiwi catchments. 

Southern Catchments

Low levels of sparse activity were detected in the southern catchments of Aotea. Analysis of hourly time/location data indicated that a communal/maternal roost was unlikely to be within any of the southern catchments during the short survey period. It is possible that bats will utilise more habitat in the southern catchments as pups are weaned if the population disperses across the landscape. 

Dark Sky Sanctuary

Aotea is accredited as a Dark Sky Sanctuary and there is little lighting on the islands roads, which pekepeka utilise to commute between catchments. Roadside lighting is believed to increase prey for bat species but may turn them away from their normal com-muting route. The dark skies of the motu may well be advantageous to pekapeka(2).

The survey will not detect all bats, as it utilises patterns of activity across the landscape to make generalised inferences. Also this survey did not include any DOC managed land. The main finding was that bats are more active in the north of Aotea. In future, further surveys and more input from the community should provide a clearer picture of bat activity across the motu. A handheld bat detector will be available through Aotea’s Ecology Vision program to loan to community groups wishing to under-take their own localised surveys, contact: ecologyvisiongbi@gmail.com 

To view the full survey report, visit: https://ecologyvision.co.nz/2022/02/08/aotea-autonomous-pekapeka-survey-2021/ 

References:

1. O’Donnell CFJ,Borkin KM, Christie JE, Lloyed B, Parsons SE, Hitchmough RA (2017). Conservation status of New Zealand bats, 2018. Department of Conservation, Wellington. ISSN 2324-1713 (web PDF). 

2. Jones C, Borkin K, Smith D (2019). Roads and wildlife: the need for evidence-based decisions; New Zealand bats as a case study. New Zealand Journal of Ecology 43 (2): 3376.