Conservation Management of the Brothers Island Tuatara (Sphenodon Guntheri): Monitoring the Translocated Matiu/Somes Island Population

Abstract

The conservation management plan for Sphenodon guntheri, a threatened species, was to translocate 54 individuals to a new island habitat to increase the security of existing populations. Post release monitoring was necessary to determine how well the population adapted to the new environment, whether the goals for the translocation were achieved and as initial protection against any detrimental factors or threats. The three goals for this study were: to evaluate the success (in terms of survival, growth and condition) of translocating 54 tuatara to Matiu/Somes Island (New Zealand) in 1998; to investigate tuatara burrowing habits on Matiu/Somes Island; and to investigate the diet of tuatara on Matiu/Somes Island. Over two years, 44 percent of the released individuals were recaptured. These individuals had gained significant amounts of weight and dispersed up to 300 metres away from the release sites. Burrow surveys revealed that a variety of physical and thermal conditions are tolerated. An 'ideal' set of conditions could not be determined. The diet of these animals was mainly Mimopeus and Mecodema beetles, hunting spiders, snails, ground and tree weta (Hemideina spp.). This indicated no conflict with conservation or restoration goals caused by tuatara eating other introduced endangered species.