Extreme longevity of the common gecko (Hoplodactylus maculatus) on Motunau Island, Canterbury, New Zealand

The longevity of common geckos (Hoplodactylus maculatus) on predator-free Motunau Island, North Canterbury, was investigated. Sixteen of 133 individuals marked between 1967-75 were re-captured in the summer of 1996/97. A growth curve was generated to estimate the age of these geckos at first capture, and from this their age in 1996/97; 10 were estimated to be at least 36 years old. In this cool-temperate habitat, H. maculatus matures late and has a low annual reproductive output over an extended lifespan. This suggests that nearby mainland populations would be particularly slow to recover from the impacts of introduced mammalian predators

Implications of past and future vegetation change for the lizard fauna of Motunau Island

Abundance, distribution and habitat preferences of the lizard species present on Motunau Island, off the Canterbury coast of New Zealand, were investigated. The aim of the study was to investigate the extent to which recent vegetation change on Motunau Island has effected the lizard community and what implications this has for the future management of the Island. Three species of lizard occur on Motunau Island; the common gecko (Hoplodactylus maculatus), common skink (Oligosoma nigriplantare polychroma) and spotted skink (O. lineoocellatum). Rabbits (Oryctolagus cuniculus) were present on the island from 1862 until their eradication in 1962. Since then, vegetation on the island has changed from being tussock-dominated to being dominated by exotic weeds. Data from lizard pitfall trap surveys carried out in 1967-75 by Tony Whitaker of the Department of Scientific and Industrial Research (DSIR) were compared with new pitfall trapping data to determine if changes in the lizard population had occurred in response to these vegetation changes. The abundance of O. n. polychroma and H. maculatus does not appear to change significantly. The distribution of these two species were significantly correlated but neither showed any preference for a particular type. The abundance of O. lineoocellatum was significantly greater in 1996/97 than in the earlier DSlR surveys. This could be a result of the vegetation becoming more open and more structurally complex since the early surveys. This would offer greater opportunities for O. lineoocellatum (which is strongly heliothermic) to thermoregulate and forage. O. lineoocellatum showed no consistent significant preference towards any habitat type, although they tended to be found more in 'margin' habitat. Research into pitfall trapping and the way lizard behaviour may influence pitfall trapping data needs to be undertaken as there is a possible trap bias in this study. Management of Motunau Island needs to ensure that a structurally complex environment is maintained to ensure high numbers of all three lizard species can continue to coexist

Responses of the native skink Leiolopisma maccanni to two pest control baits

This study investigated the attractiveness of two vertebrate pest baits (nontoxic RS5 and Pindone-impregnated AgTech) to captive skinks Leiolopisma maccanni. The trial was conducted in January 1995 by the Department of Entomology and Animal Ecology, Lincoln University, for the Department of Conservation

A survey of the birds, lizards and mammals of Motunau Island, Canterbury, New Zealand, with emphasis on the effects of vegetation change on the breeding success of burrowing seabirds

An ecological survey of Motunau Island was carried out between 1958 and 1962 at the time rabbits were exterminated from the island. Since then the vegetation has changed from one dominated by native plants, to one dominated by exotics. Birds, lizards and vegetation were resurveyed in 1996/97. This report describes the distribution of burrows and nests of seabirds and shore-birds breeding on Motunau Island, and records all other birds and mammals seen on or at sea close to the island. The status of lizards was "determined in the quadrat used in the previous survey. Data from the 1996/97 survey is compared with that of 1958-62. A survey of present vegetation is underway. While burrowing seabird numbers appear stable, vegetation change may be effecting the ability of the small petrels to utilise certain areas of the island resulting in distributional change of their breeding sites on the island. Sixteen of the Hoplodactylus maculatus toe-clipped during the previous survey were recovered in 1996/97. An increase in the density of both species of skinks was recorded