Browsing by Author "Abreu-Grobois, F Alberto"

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    Recent advances on the estimation of the thermal reaction norm for sex ratios.
    (PeerJ, 2020-01) Abreu-Grobois, F Alberto; Morales-Mérida, B Alejandra; Hart, Catherine E; Guillon, Jean-Michel; Godfrey, Matthew H; Navarro, Erik; Girondot, Marc
    Temperature-dependent sex determination, or TSD, is a widespread phenomenon in reptiles. The shape of the relationship between constant incubation temperature and sex ratio defines the TSD pattern. The TSD pattern is considered a life-history parameter important for conservation because the wider the range of temperatures producing both sexes, the more resilient the species is to climate change impacts. We review the different published equations and methodologies that have been used to model TSD patterns. We describe a new flexible model that allows for an asymmetrical pattern around the pivotal temperature, which is the constant temperature producing both sexes in equal proportions. We show that Metropolis-Hastings with Markov chain produced by a Monte Carlo process has many advantages compared to maximum likelihood and is preferred. Finally, we apply the models to results from incubation experiments using eggs from the marine turtle Lepidochelys olivacea originating in Northeast Indian, East Pacific, and West Atlantic Regional Management Units (RMUs) and find large differences in pivotal temperatures but not in transitional ranges of temperatures.
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    Regional Management Units for Marine Turtles: A Novel Framework for Prioritizing Conservation and Research across Multiple Scales
    (2010) Wallace, Bryan P; DiMatteo, Andrew D; Hurley, Brendan J; Finkbeiner, Elena M; Bolten, Alan B; Chaloupka, Milani Y; Hutchinson, Brian J; Abreu-Grobois, F Alberto; Amorocho, Diego; Bjorndal, Karen A; Bourjea, Jerome; Bowen, Brian W; Dueñas, Raquel Briseño; Casale, Paolo; Choudhury, BC; Costa, Alice; Dutton, Peter H; Fallabrino, Alejandro; Girard, Alexandre; Girondot, Marc; Godfrey, Matthew H; Hamann, Mark; López-Mendilaharsu, Milagros; Marcovaldi, Maria Angela; Mortimer, Jeanne A; Musick, John A; Nel, Ronel; Pilcher, Nicolas J; Seminoff, Jeffrey A; Troëng, Sebastian; Witherington, Blair; Mast, Roderic B
    Background: Resolving threats to widely distributed marine megafauna requires definition of the geographic distributions of both the threats as well as the population unit(s) of interest. In turn, because individual threats can operate on varying spatial scales, their impacts can affect different segments of a population of the same species. Therefore, integration of multiple tools and techniques - including site-based monitoring, genetic analyses, mark-recapture studies and telemetry - can facilitate robust definitions of population segments at multiple biological and spatial scales to address different management and research challenges. Methodology/Principal Findings: To address these issues for marine turtles, we collated all available studies on marine turtle biogeography, including nesting sites, population abundances and trends, population genetics, and satellite telemetry. We georeferenced this information to generate separate layers for nesting sites, genetic stocks, and core distributions of population segments of all marine turtle species. We then spatially integrated this information from fine-to coarse-spatial scales to develop nested envelope models, or Regional Management Units (RMUs), for marine turtles globally. Conclusions/Significance: The RMU framework is a solution to the challenge of how to organize marine turtles into units of protection above the level of nesting populations, but below the level of species, within regional entities that might be on independent evolutionary trajectories. Among many potential applications, RMUs provide a framework for identifying data gaps, assessing high diversity areas for multiple species and genetic stocks, and evaluating conservation status of marine turtles. Furthermore, RMUs allow for identification of geographic barriers to gene flow, and can provide valuable guidance to marine spatial planning initiatives that integrate spatial distributions of protected species and human activities. In addition, the RMU framework - including maps and supporting metadata - will be an iterative, user-driven tool made publicly available in an online application for comments, improvements, download and analysis.