skink

Partnership between COET and DOC

COET's work is closely aligned with and supported by the Department of Conservation (DOC). COET and DOC’s Grand and Otago Skink (GAOS) Recovery Programme are formal partners with corresponding objectives to promote public education and advocacy, support captive breeding, and provide protected sanctuaries for wild populations of grand and Otago skinks.

COET is taking a lead in community education and has recently hosted a joint community field day at the Mokomoko dryland sanctuary with DOC. The GAOS team was involved in the assessment of this sanctuary site as suitable habitat for Otago skinks and provided assistance with permits. DOC was able to quarantine the captive born skinks which were to be translocated into the sanctuary in order to screen them for diseases and parasites as well as conducting general health checks of the animals.

Details of DOCs recovery programme for grand and Otago skinks are summarised below. For information on skink biology and factors that could be contributing to their decline, refer to Flora & Fauna.

The Grand and Otago Skink Recovery Programme

DOC undertook a 3 year experimental management programme (2006-2008) at Macraes Flat, in Otago, to identify a viable management option for the recovery of the endangered grand and Otago skinks. The research involved the establishment of mammal proof fences and extensive trap lines around known skink habitat and existing skink populations to assess the impact of invasive mammals on these populations. Results from the research have shown that eradication or intensive control of introduced mammalian predators can reverse the decline in skink numbers. Grand and Otago skink numbers within the managed areas at Macraes Flat have doubled over a 3-4 year period.

Due to the proven success of management techniques, protection and monitoring of grand and Otago skinks in the east of their range continues at Macraes Flat. The GAOS team also monitors isolated skink populations in the west of their range near Wanaka.

Predator control to protect skinks

A range of invasive mammalian predators have been implicated in the decline of grand and Otago skinks including cats, stoats, ferrets, weasels and hedgehogs. Predators are controlled via trapping and exclusion fences at Macraes Flat. A wide range of trap types (including both kill traps and live trapping) are used in combination with a variety of baits (eggs, rabbit and fish) to target a broad range of predator species. The trapping network was expanded from 2100ha to 4660ha in 2008/09 and includes both conservation estate and private land. Experimental mammal proof fences have been constructed to exclude predators. These fences have a small mesh size, a hood to prevent animals climbing over the top and a buried skirt to prevent animals from burrowing underneath. All predators were removed from within the fenced areas and regular monitoring is carried out to ensure that predators do not recur. Two fenced areas have been constructed; one at an area known as Wildlife (20 ha: gully habitat) was built in winter 2005 and one at Redbank (9 ha: ridgetop habitat) was established in winter 2007. 

Population monitoring to inform managers

The responses of skink populations to current management techniques are monitored across the Macraes Flat area. Monitoring is also carried out in the west near Wanaka to assess the status of populations there. Both Otago and grand skinks have been monitored in the wild since 2005 using Photo-Resight (P-R) methods (aka photo Mark-Recapture). This method relies on the fact that individual Otago and grand skinks are recognisable by the unique markings and patterns on the side of their head, these markings do not change considerably as the skinks age. By revisiting the same sites over a period of time the GAOS team can build up a catalogue of individuals that occur at each site. Statistical methods are then employed to estimate survival and population change for skinks using the P-R method at each key site.

Captive management to provide additional security

Management is not currently practical for both species across the whole of their ranges, so it is essential that the genotypes of the grand and Otago skinks are secured. Both species have disjunct ranges with isolated populations in the east and west of their range and thus genetic diversity from both populations must be protected. A captive management programme has been developed in co-operation with private breeders and zoological institutions to protect and maintain the diversity of skinks and as insurance from extinction in the wild. A captive husbandry manual has also been developed to aid captive management by producing guidelines for grand and Otago skink husbandry.

Advocacy and community relations to build support

Community involvement in skink recovery and ecological restoration of drylands is essential to the long-term success of the programme. The grand and Otago skink team has hosted community days, university and conference open days and have visited many local schools to deliver education and advocacy programmes. The grand and Otago skink recovery programme also relies on good relationships with many neighbouring landowners for access to sites.

Supplementary research to broaden knowledge

A number of collaborative projects are conducted by Landcare Research, the University of Otago and numerous volunteers in association with the GAOS programme. Research includes the wider effects of the GAOS trapping network on the ecosystem, the relationship between skink populations and vegetation and landuse and movements of Otago skinks (via radiotracking).

For more information about the Otago or grand skink and their conservation visit the Department of Conservation website or contact John Keene or Terra Dumont:

Central Otago Office
43 Dunstan Rd, Alexandra 9320

Tel: 03-440 2040

Email John Keene jkeene@doc.govt.nz

Email Terra Dumont tdumont@doc.govt.nz