Tuatara are ancient reptiles unique to New Zealand, now surviving only on predator-free islands with ongoing welfare concerns around climate warming effects on sex ratios.
Climate warming is shifting nest temperatures toward male-producing ranges, creating population-wide sex ratio imbalances that threaten long-term viability. Handling for research is stressful for animals that experience very slow metabolic rates. Reintroduction to new islands involves transport stress. Competition with introduced lizards on some islands creates resource competition.