Aims: Identifying major reasons for species imperilment is a necessary step for conservation, yet the degree to which we can generalize is hard for species-rich yet less-studied taxa, such as lizards. Here, we aim to bridge the gap by providing comprehensive analyses of the correlates and processes of species extinction and threats for global lizards. Location: Global Time period: Current Major taxa studied: Lizards Methods: We compiled a dataset comprising extinction risk status, six intrinsic traits, and seven extrinsic factors for 5256 lizard species. We carried out binomial distribution tests for 43 families and seven realms to check the non-randomness in species’ extinction risk and then employed phylogenetic linear regressions to identify the key factors that relate to the extinction proneness of lizards and species subgroups. Based on the IUCN threat assessment, we identified major threats for global lizards and for major families and regions. Results: We found strong evidence of taxonomic and geographical non-randomness in the extinction risk of lizards. Geographical range size, human footprint and density, insular endemism, temperature and precipitation seasonality, and body size were key predictors of extinction risk, and the first three factors were also important across families and realms. Moreover, newly described species were more likely to have a restricted range size and a higher extinction risk. Globally, the most detrimental threat was habitat destruction, while overexploitation, species invasion, and climate change varied widely in importance among species groups. Main conclusions: Overall, we highlight the detrimental influences of range restriction, climate variability, and anthropogenic threats to species persistence. We suggest that lizards are potentially at high risk of extinction due to widespread human disturbance and species with extinction-prone traits require conservation prioritization. Moreover, lizards of different families and regions require different management strategies because of variation in extinction-risk correlates and threats. --
The intrinsic predictors were collected from Meiri, 2018, Skeels et al. (2020), and Caetano et al. (2022). The extrinsic factors were calculated by mapping the environmental raters to the species distribution grids based on the shapefiles of the Global Assessment of Reptile Distributions (GARD; Roll & Meiri, 2022).
1. Meiri, S. (2018). Traits of lizards of the world: Variation around a successful evolutionary design. Global ecology and biogeography, 27, 1168–1172.
2. Skeels, A., Esquerré, D., & Cardillo, M. (2020). Alternative pathways to diversity across ecologically distinct lizard radiations. Global Ecology and Biogeography, 29, 454–469.
3. Roll, U., & Meiri, S. (2022). Data from: GARD 1.7—updated global distributions for all terrestrial reptiles. Dryad Digital Repository.
4. Caetano, G. H. D. O., Chapple, D. G., Grenyer, R., Raz, T., Rosenblatt, J., Tingley, R., ... & Roll, U. (2022). Automated assessment reveals that the extinction risk of reptiles is widely underestimated across space and phylogeny. PLoS Biology, 20, e3001544.
We used R and the packages listed below to carry out the analyses. The phylogenetic linear regression model was performed using the package phylolm (https://github.com/lamho86/phylolm). The model averaging analyses were performed by using the package MuMIn (https://cran.r-project.org/package=MuMIn).
