A global reptile assessment highlights shared conservation needs of tetrapods

Comprehensive assessments of species’ extinction risks have documented the extinction crisis and underpinned strategies for reducing those risks. Global assessments reveal that, among tetrapods, 40.7% of amphibians, 25.4% of mammals and 13.6% of birds are threatened with extinction. Because global assessments have been lacking, reptiles have been omitted from conservation-prioritization analyses that encompass other tetrapods. Reptiles are unusually diverse in arid regions, suggesting that they may have different conservation needs. Here we provide a comprehensive extinction-risk assessment of reptiles and show that at least 1,829 out of 10,196 species (21.1%) are threatened—confirming a previous extrapolation and representing 15.6 billion years of phylogenetic diversity. Reptiles are threatened by the same major factors that threaten other tetrapods—agriculture, logging, urban development and invasive species—although the threat posed by climate change remains uncertain. Reptiles inhabiting forests, where these threats are strongest, are more threatened than those in arid habitats, contrary to our prediction. Birds, mammals and amphibians are unexpectedly good surrogates for the conservation of reptiles, although threatened reptiles with the smallest ranges tend to be isolated from other threatened tetrapods. Although some reptiles—including most species of crocodiles and turtles—require urgent, targeted action to prevent extinctions, efforts to protect other tetrapods, such as habitat preservation and control of trade and invasive species, will probably also benefit many reptiles.Neil Cox, Bruce E. Young, Philip Bowles, Miguel Fernandez, Julie Marin, Giovanni Rapacciuolo, Monika Böhm, Thomas M. Brooks, S. Blair Hedges, Craig Hilton-Taylor, Michael Hoffmann, Richard K. B. Jenkins, Marcelo F. Tognelli, Graham J. Alexander, Allen Allison, Natalia B. Ananjeva, Mark Auliya, Luciano Javier Avila, David G. Chapple, Diego F. Cisneros-Heredia, Harold G. Cogger, Guarino R. Colli, Anslem de Silva, Carla C. Eisemberg, Johannes Els, Ansel Fong G., Tandora D. Grant, Rodney A. Hitchmough, Djoko T. Iskandar, Noriko Kidera, Marcio Martins, Shai Meiri, Nicola J. Mitchell, Sanjay Molur, Cristiano de C. Nogueira, Juan Carlos Ortiz, Johannes Penner, Anders G. J. Rhodin, Gilson A. Rivas, Mark-Oliver Rödel, Uri Roll, Kate L. Sanders, Georgina Santos-Barrera, Glenn M. Shea, Stephen Spawls, Bryan L. Stuart, Krystal A. Tolley, Jean-François Trape, Marcela A. Vidal, Philipp Wagner, Bryan P. Wallace, Yan Xi

Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements