DOC trialled electric fencing in kākāpō sanctuary
The Department of Conservation tested electric fences at Codfish Island in 2020 and 2021 as part of a research trial to establish fenced kākāpō sanctuaries.
DOC kākāpō operations manager Deidre Vercoe said that while designing the best barrier system to prevent kākāpō from escaping fenced sanctuaries, it trialled electric fencing, but found while it was safe for the birds, it did not prevent them from climbing.
The trial was carried out in November 2020 and February 2021, with 19 birds, so DOC could observe a variety of different behaviours to the fences, she said.
The birds were placed in a 11m2 triangular pen, with two sides of the triangle being ply and the other a 6m section of pest-proof fence. Energisers on the fence produced a voltage that ranged from 4.2 to 7.7 kilovolts and birds were in the pen for no more than two hours, she said.
‘‘Each bird interacted with the fence differently, meaning not all of them received an electric shock. Some of the birds jumped to the ground following an interaction with the electrified wire while others continued to climb past it,’’ she said.
The work underwent approval by DOC’s animal ethics committee, which approved it and attended the first trial in November 2020, she said.
‘‘The kākāpō team’s technical and veterinary advisers were present throughout the entire trial involving electrical fencing and no adverse effects were identified in the birds that participated in the trial,’’ she said.
DOC had been looking at electric fences as a method of controlling kākāpō as the flightless birds were
‘‘exceptionally good climbers’’, which would need to be considered when planning future sanctuaries.
‘‘If they lived in a fenced sanctuary, this would need to be addressed, as fences at sanctuaries are designed to stop predators getting in – not to stop kākāpō from climbing out,’’ Vercoe said.
‘‘If they escaped, they would be at risk of predation, vehicle collision or interaction with whatever other dangers exist outside the fenced sanctuary.’’
DOC had looked at a number of styles of fenced barriers and electric fencing to prevent kākāpō escaping from enclosures over the years, she said.
‘‘Kākāpō can easily climb a wooden post on the inside of a fence, or climb up wire netting or anything they can gain purchase with by using their beak and claws, so physical barriers such as a seamless, wide strip of tin attached to the inside of the fence, have been trialled,’’ she said.
Kākāpō were not deterred by the electric fence trialled on Whenua Hou and as such it was no longer being pursued as an option.
It comes as 55 of the 60 kākāpō chicks hatched during the 2022 breeding season have survived, bringing the total population in New Zealand to 252.
Kākāpō last bred in early 2019, when 73 chicks hatched.
Kākāpō are located on the predator free islands of Whenua Hou (Codfish Island), Anchor Island in Fiordland, Hauturu-o-Toi (Little Barrier) Island near Auckland and Te Kākahu-o-Tamatea (Chalky Island) in Southland. ‘‘However as the population grows, we are looking for new sites for kākāpō to live, which includes looking at fenced sanctuaries.’’
DOC was currently working towards establishing kākāpō within a fenced sanctuary at Maungatautari, near Cambridge, and was exploring the feasibility of housing kākāpō in other offshore islands in Fiordland.
‘‘Ultimately DOC and Ngāi Tahu support predator-free Rakiura as a potential game changer for kākāpō conservation. We are closely following the progress towards this vision,’’ Vercoe said.