1. Assessing the impacts of multiple, often synergistic, stressors on the population dynamics of long-lived species is becoming increasingly important due to recent and future global change. 2. Tiliqua rugosa (sleepy lizard) is a long-lived skink (>30 years) that is adapted to survive in semi-arid environments with varying levels of parasite exposure and highly seasonal food availability. We used an exhaustive database of 30-years of capture-mark-recapture records to quantify the impacts of both parasite exposure and environmental conditions on the lizard's survival rates and long-term population dynamics. 3. Lizard abundance was relatively stable throughout the study period; however there were changing patterns in adult and juvenile apparent survival rates, driven by spatial and temporal variation in levels of tick exposure and temporal variation in environmental conditions. Extreme weather events during the winter and spring seasons were identified as important environmental drivers of survival. 4. Climate models predict a dramatic increase in the frequency of extreme hot and dry winter and spring seasons in our South Australian study region; from a contemporary probability of 0.17 up to 0.47 - 0.83 in 2080 depending on the emissions scenario. Our stochastic population model projections showed that these future climatic conditions will induce a decline in the abundance of this long-lived reptile of up to 67% within 30 years from 2080, under worst case scenario modelling. 5. The results have broad implications for future work investigating the drivers of population dynamics and persistence. We highlight the importance of long-term datasets and accounting for synergistic impacts between multiple stressors. We show that predicted increases in the frequency of extreme climate events have the potential to considerably and negatively influence a long-lived species, which might previously have been assumed to be resilient to environmental perturbations.
Lizard capture mark recapture data
The first worksheet contains the capture history for each of the 5849 individual sleepy lizards in the sampled population throughout the 30-year study. The raw capture data was pooled to an annual time period, therefore the capture histories are continuous, annual resolution data from 1982 - 2011. Each row is the data from a different individual. The first column contains the capture histories in Rmark multi-state format where each letter represents a capture event in a different 'tick exposure risk state': A = B. hydrosauri low, B = B. hydrosauri moderate, C = B. hydrosauri high, D = A. limbatum low, E = A. limbatum moderate, F = A. limbatum high. A zero in the capture history means that the individual was not encountered at that period in the time series. The second column contains the age of the individual *at first capture*. The second sheet contains the annual environmental data that were used as covariates in the multi-state capture-mark-recapture models.
Multistate_capture_mark_recapture_data_RMark_format.xlsx
BASELINE worst case RAMAS female only model
This is the RAMAS metapopulation model file for estimating the the baseline (current conditions) effect of 'hot and dry' and 'cool and wet' winter and spring conditions on the sleepy lizard study population. The effect of these extreme conditions are based on the largest effect size estimated from the capture-mark-recapture models (i.e. worst case).
BASELINE_worst_case_female_only.mp
POLICY worst case female only RAMAS model
This is the RAMAS metapopulation model file for estimating the the worst case effect of 'hot and dry' and 'cool and wet' winter and spring conditions on the sleepy lizard study population in the future. The probabilities of extreme conditions are based on regional temperature and rainfall forecasts from an ensemble climate model under policy greenhouse gas emission scenarios.
POLICY_worst_case_female_only.mp
REFERENCE worst case female only RAMAS model
This is the RAMAS metapopulation model file for estimating the the worst case effect of 'hot and dry' and 'cool and wet' winter and spring conditions on the sleepy lizard study population in the future. The probabilities of extreme conditions are based on regional temperature and rainfall forecasts from an ensemble climate model under reference greenhouse gas emission scenarios.
REFERENCE_worst_case_female_only.mp
BASELINE best case female only RAMAS model
This is the RAMAS metapopulation model file for estimating the the baseline (current conditions) effect of 'hot and dry' and 'cool and wet' winter and spring conditions on the sleepy lizard study population. The effect of these extreme conditions are based on the smallest effect size estimated from the capture-mark-recapture models (i.e. best case).
BASELINE_best_case_female_only.mp
POLICY best case female only RAMAS model
This is the RAMAS metapopulation model file for estimating the the best case effect of 'hot and dry' and 'cool and wet' winter and spring conditions on the sleepy lizard study population in the future. The probabilities of extreme conditions are based on regional temperature and rainfall forecasts from an ensemble climate model under policy greenhouse gas emission scenarios.
POLICY_best_case_female_only.mp
REFERENCE best case female only RAMAS model
This is the RAMAS metapopulation model file for estimating the the best case effect of 'hot and dry' and 'cool and wet' winter and spring conditions on the sleepy lizard study population in the future. The probabilities of extreme conditions are based on regional temperature and rainfall forecasts from an ensemble climate model under reference greenhouse gas emission scenarios.
REFERENCE_best_case_female_only.mp