There have been around 14 species of lizards identified on Barrier.
Skinks and geckos are present in many places on the island but little is
know about how well they are surviving with our high numbers of rats and
feral cats. Like lizards all over the world they are difficult to
monitor, being shy and often well camouflaged creatures.
In January 2007 Trent Bell from Landcare Research established 300 foam
artificial covers onto trees at Windy Hill and Benthorn Farm within the
Windy Hill Rosalie Bay Catchment Trust sanctuary area where rats and
feral cats are managed to low densities. The objective of the project is
to establish a method that allows for more effective monitoring of
lizard presence and densities, particularly were numbers of animals are
known to be at low levels. The current methods of trapping and night
spotting are time consuming and the results often inconclusive.
Hill is part of a three site research project taking place here on Great
Barrier, on pest-free Fanal Is. in the Mokohinaus, and at Karori
Sanctuary in Wellington. The trial has so far found that certain types
of gecko will use the covers, Pacific geckos at Windy Hill and Forest
geckos at Karori. As would be expected at Fanal Island where lizard
numbers are very high, a range of lizards use the covers including the
At Windy Hill and Benthorn Farm Trent found that small numbers of
pacific gecko (9 in 2008,18 in 2009) and some sub-adults were present
which indicated successful breeding. Covers are currently set out in
transects (long lines) and later this year Trent hopes to establish
clusters of the covers around the place on the transects where geckos
were found. This way he hopes to get a better idea of the numbers of
geckos present. Most lizards breed very slowly and more so when the
numbers of breeding adults are much reduced through long term predation.
Landcare Research has been granted funding to continue and expand this
research as part of a Government initiative to increase the populations
of iconic species, such as lizards, by 25%. The Windy Hill Rosalie Bay
Catchment Trust also monitors lizards using layers of Onduline to form
lizard ‘motels’ and has found that Ornate lizards use these exclusively
to other lizard species.
The benefit to the Trust and the island of the Landcare Research is the
increased knowledge gained about the lizard populations here, the
opportunity to work with an expert in his field, and the opportunity to
contribute to science that may be applicable both in NZ and worldwide. A
full report will be published in 2013.