Brothers Island tuatara  (Sphenodon guntheri)

Evidence suggests that the tuatara cannot persist in areas where rats are present due to competition with these fast breeding rodents. They do not occur on Brothers Island but there is concern that Polynesian rats, Rattus exulans, which occur on other islands, may spread by boats and on driftwood to Brothers Island (7). Tuatara are also predated on by introduced animals such as dogs and cats (8). Furthermore, scientists warn that climate change could have significant impact on this species as the eggs are sensitive to small changes in temperature that could alter the sex ratio and unbalance the reproductive success of a population. Tuatara have, however, survived 200 million years, so may have mechanisms to cope with climate change, though it is feared that the climate change of the future may occur at a faster rate than tuatara can adapt, physiologically or behaviourally (9).

Brothers Island tuatara is one of the oldest animals in existence and is heavily protected under the Wildlife Act in New Zealand. The island it occurs on is designated as a Wildlife Sanctuary and as a Flora and Fauna Reserve, and permits are required for visits (2). Every precaution is taken to prevent rodents gaining access to this island and threatening the populations, although this cannot be guaranteed (2). New Zealand's Wildlife Service has been running a long-term research programme on the ecology of the two tuatara species and factors affecting their survival, in order to best decide on conservation measures (7). While these measures are considered adequate, there are concerns that any threat could have significant impacts on this species due to its incredibly slow reproductive rate and poor adaptability. As a precaution, in 1995, 68 Brothers Island tuataras were Titi Island in Cook Strait (8). Following this success another 54 individuals were introduced to Matui island, where tourists are able to view them and learn more about the need to protect this rare species (8). A recent recovery plan has been published for the tuatara which focuses on developing current initiatives and monitoring the gene pools of each population (8). Conservation and continued research is essential to ensure that we do not lose the oldest living reptile in the world (2).