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Post-translocation monitoring is fundamental for assessing translocation success and identifying potential threats. We measured outcomes for four cohorts of tuatara Sphenodon punctatus translocated to warmer climates outside of their ecological region, to understand effects of climate warming. Translocation sites were on average 2–4 °C warmer than the source site. We used three short-term measures of success: survival, growth and reproduction. Data on recaptures, morphometric measurements, and reproduction were gathered over 2.5 years following release. Although decades of monitoring will be required to determine long-term translocation success in this species, we provide an interim measure of population progress and translocation site suitability. We found favourable recapture numbers, growth of founders and evidence of reproduction at most sites, with greater increases in body mass observed at warmer, less densely populated sites. Variable growth in the adult population at one translocation site suggested that higher population density, intraspecific competition, and lower water availability could be responsible for substantial weight loss in multiple individuals, and we make management recommendations to reduce population density. Overall, we found that sites with warmer climates and lower population densities were potentially beneficial to translocated tuatara, probably because of enhanced temperature-dependent and density-dependent growth rates. We conclude that tuatara could benefit from translocations to warmer sites in the short term, but further monitoring of this long-lived species is required to determine longer-term population viability following translocation. Future vulnerability to rising air temperatures, associated water availability, and community and ecosystem changes beyond the scope of this study must be considered. [ABSTRACT FROM AUTHOR]

Abstract: Aim: Predicting the distribution of species relies increasingly on understanding the spatially explicit constraints of environmental conditions on an organism's physiological traits. We combined an empirical model of temperature‐dependent embryonic development with a mechanistic model of soil temperatures to examine potential thermal limitations on the distribution of a nocturnal, oviparous skink, Oligosoma suteri, a range‐restricted endemic. Location: New Zealand. Methods: We estimated a thermal requirement for successful embryonic development as 616 degree‐days above a threshold of 13.8°C. We then modelled soil temperatures at representative sites across New Zealand and predicted duration of incubation to map the distribution of potentially viable oviposition sites, given variation in the timing of egg‐laying under even temperature increases. Results: Successful development of O. suteri embryos is possible in locations outside their current distribution. Increasing temperatures increased the species’ potential range, reducing incubation duration and lengthening the oviposition window. However, due to the disconnected nature of their rocky shore habitat, individuals may not be able to disperse to currently uninhabited sites within that extended range. Additionally, although locations may be thermally suitable for incubation, predation by introduced mammals, competition and habitat modification may prevent successful establishment of populations. Main conclusions: Our models contribute to understanding fundamental physiological constraints on an important life history stage that will inform conservation management actions, including potential future translocations. [ABSTRACT FROM AUTHOR]

Global climate change is of particular concern for small and isolated populations of reptiles with temperature-dependent sex determination because low genetic variation can limit adaptive response in pivotal temperatures, leading to skewed sex ratios. We explore the demographic consequences of skewed sex ratios on the viability of a tuatara population characterized by low genetic diversity. We studied the rare species of tuatara ( Sphenodon guntheri) on the 4 ha North Brother Island in New Zealand over two nesting seasons and captured 477 individuals, with a 60% male bias in the adult population. Females first breed at 15 years and have extremely low rates of gravidity, producing clutches of three to eight eggs every 9 years. Simulations of the population using population viability analysis showed that the current population is expected to persist for at least 2000 years at hatchling sex ratios of up to 75% male, but populations with 85% male hatchlings are expected to become extinct within approximately 300 years (some eight generations). Incorporation of inbreeding depression increased the probability of extinction under male biased sex ratios, with no simulated populations surviving at hatchling sex ratios >75% male. Because recent models have predicted that climate change could lead to the production of all male S. guntheri hatchlings by 2085, we examined whether periodic intervention to produce mixed or female biased sex ratios would allow the population to survive if only males were produced in natural nests. We show that intervention every 2–3 years could buffer the effects of climate change on population sex ratios, but translocation to cooler environs might be more cost-effective. Climate change threatens tuatara populations because neither modified nesting behaviour nor adaptive response of the pivotal temperature can modify hatchling sex ratios fast enough in species with long generation intervals. [ABSTRACT FROM AUTHOR]