scholarly journals Feminization of hawksbill turtle hatchlings in the twenty-first century at an important regional nesting aggregation

2021 ◽  
Vol 44 ◽  
pp. 149-158
Author(s):  
M Chatting ◽  
S Hamza ◽  
J Al-Khayat ◽  
D Smyth ◽  
S Husrevoglu ◽  
...  
Keyword(s):  
Climate Change ◽  
Sex Ratios ◽  
First Century ◽  
Climate Data ◽  
Temperature Dependent ◽  
Eretmochelys Imbricata ◽  
Climate Forecasts ◽  
The Face ◽  
Incubation Temperatures ◽  
Hawksbill Turtles

Projected climate change is forecasted to have significant effects on biological systems worldwide. Marine turtles in particular may be vulnerable, as the sex of their offspring is determined by their incubating temperature, termed temperature-dependent sex determination. This study aimed to estimate historical, and forecast future, primary sex ratios of hawksbill turtle Eretmochelys imbricata hatchlings at an important nesting ground in northeastern Qatar. Incubation temperatures from the Arabian/Persian Gulf were measured over 2 nesting seasons. Climate data from same period were regressed with nest temperatures to estimate incubation temperatures and hatchling sex ratios for the site from 1993 to 2100. Future hatchling sex ratios were estimated for 2 climate forecasts, one mid-range (SSP245) and one extreme (SSP585). Historical climate data showed female-biased sex ratios of 73.2 ± 12.1% from 1993 to 2017. Female biases from 2018 to 2100 averaged 85.7% ± 6.7% under the mid-range scenario and 87.9% ± 5.4% under the high-range scenario. In addition, predicted female hatchling production was >90% from 2054 and 2052 for SSP245 and SSP585, respectively. These results show that hawksbill primary sex ratios in Qatar are at risk of significant feminization by the year 2100 and that hawksbill turtle incubation temperatures in an extreme, understudied environment are already comparable to those predicted in tropical rookeries during the latter half of the 21st century. These results can help conservationists predict primary sex ratios for hawksbill turtles in the region in the face of 21st-century climate change.

scholarly journals Feminization of Hawksbill Turtle hatchlings in the Twenty-first Century at an important Regional Nesting Aggregation

2021 ◽  
Author(s):  
Mark Chatting ◽  
Shafeeq Hamza ◽  
Jassim Al-Khayat ◽  
David Smyth
Keyword(s):  
Climate Change ◽  
At Risk ◽  
Sex Ratios ◽  
First Century ◽  
Climate Data ◽  
Eretmochelys Imbricata ◽  
Marine Turtles ◽  
Historical Climate ◽  
Incubation Temperatures ◽  
Nesting Aggregation

Projected climate change is forecasted to have significant effects on biological systems worldwide. Marine turtles in particular may be vulnerable, as the sex of their offspring is determined by their incubating temperature. This study is aimed to estimate historical and forecast future, primary sex ratios of hawksbill turtle hatchlings, Eretmochelys imbricata, in Qatar. Incubation temperatures were measured over two nesting seasons. Climate data from same period was regressed with nest temperatures to estimate incubation temperatures and hatchling sex ratios for the site from 1993 to 2100. Historical climate data showed female-biased sex ratios of 73.2 ±12.1% from 1993 to 2017. Female biases from 2018 to 2100 averaged 85.7% ±6.7%. In addition, predicted female hatchling production was >90% from 2054. These results show that hawksbill primary sex ratios in Qatar are at risk of significant feminization by the year 2100.

Pivotal temperature and predicted sex ratios for hatchling hawksbill turtles from Brazil

1999 ◽  
Vol 77 (9) ◽  
pp. 1465-1473 ◽  
Author(s):  
Matthew H Godfrey ◽  
Adriana F D'Amato ◽  
Maria  Marcovaldi ◽  
N Mrosovsky
Keyword(s):  
Low Temperatures ◽  
Sex Ratios ◽  
Sea Turtle ◽  
Temperature Dependent ◽  
Eretmochelys Imbricata ◽  
Conservation Implications ◽  
Incubation Duration ◽  
Incubation Temperatures ◽  
Hawksbill Turtles ◽  
Pivotal Temperature

Like all other species of sea turtle, the hawksbill turtle (Eretmochelys imbricata) exhibits temperature-dependent sexual differentiation, with high incubation temperatures producing females and low temperatures producing males. Relatively little is known about the sex ratios of hatchlings produced by nesting populations of hawksbill turtles. Here we estimate the overall seasonal sex ratios of hatchling hawksbill turtles produced in Bahia, Brazil, during 6 nesting seasons, based on incubation durations, pivotal temperature, and pivotal incubation duration. The overall sex ratio of hatchlings produced in Bahia from 1991-1992 through 1996-1997 was estimated to be >90% female, which is more female-biased than estimated sex ratios of hatchling loggerhead turtles from Bahia and Florida, U.S.A. The biological and conservation implications of skewed sex ratios are discussed.

Pivotal and beach temperatures for hawksbill turtles nesting in Antigua

1992 ◽  
Vol 70 (10) ◽  
pp. 1920-1925 ◽  
Author(s):  
N. Mrosovsky ◽  
Anna Bass ◽  
Lynn A. Corliss ◽  
James I. Richardson ◽  
Thelma H. Richardson
Keyword(s):  
Sex Ratios ◽  
Eretmochelys Imbricata ◽  
Hawksbill Turtles ◽  
Pivotal Temperature

Eggs of hawksbill turtles, Eretmochelys imbricata, from Antigua were incubated at constant tempe ratures. The pivotal temperature (the temperature at which 50% of each sex is produced) for the sample was estimated to be 29.2 °C. Sand temperatures at the depth of turtle nests were recorded over two nesting seasons at Pasture Bay, Antigua. Although sand temperatures were sometimes higher than the pivotal temperature, more often they were lower. On this basis, it is unlikely that hatchling hawksbill turtles in this area have the highly female-biased sex ratios reported for some other reptiles.

scholarly journals Temperature-dependent sex-biased embryo mortality in a bird

2008 ◽  
Vol 275 (1652) ◽  
pp. 2703-2706 ◽  
Author(s):  
Yvonne A Eiby ◽  
Jessica Worthington Wilmer ◽  
David T Booth
Keyword(s):  
Low Temperatures ◽  
Incubation Temperature ◽  
Sex Ratios ◽  
Molecular Sexing ◽  
Temperature Dependent ◽  
Female Embryo ◽  
Male Embryo ◽  
Diverse Range ◽  
Embryo Mortality ◽  
Incubation Temperatures

Sex ratios have important evolutionary consequences and are often biased by environmental factors. The effect of developmental temperature on offspring sex ratios has been widely documented across a diverse range of taxa but has rarely been investigated in birds and mammals. However, recent field observations and artificial incubation experiments have demonstrated that the hatching sex ratio of a megapode, the Australian brush-turkey ( Alectura lathami ), varied with incubation temperature; more females hatched at high incubation temperatures and more males hatched at low temperatures. Here, we investigated the causes of this temperature-dependent sex-biasing system. Molecular sexing of chicks and embryos confirmed that male embryo mortality was greater at high temperatures while female embryo mortality is greater at low temperatures, with mortality in both sexes similar at intermediate incubation temperatures. Temperature-dependent sex-biased embryo mortality represents a novel mechanism of altering sex ratios in birds. This novel mechanism, coupled with the unique breeding biology of the brush-turkey, offers a potentially unparalleled opportunity in which to investigate sex allocation theory in birds.

Planning for climate change without climate projections?

2017 ◽  
Author(s):  
Joshua J. Lawler ◽  
Julia Michalak
Keyword(s):  
Climate Change ◽  
Climate Modeling ◽  
Ecological Impacts ◽  
Climate Projections ◽  
Relative Uncertainty ◽  
Climate Change Projections ◽  
Climate Forecasts ◽  
The Face ◽  
Climate Change Concern ◽  
Conservation Plans

This chapter explores the relative uncertainty associated with popular approaches to conservation planning in the face of climate change. Concern about uncertainties inherent in climate-change projections and associated ecological impacts have led many in the conservation community to avoid climate modeling, and instead favor forecast-free approaches that involve increasing connectivity and protecting “nature’s stage” (geophysical settings) to produce climate-smart conservation plans. A comparison of each of these approaches reveals that the uncertainties associated with connectivity modeling and mapping geophysical settings can be as large, if not larger than, the uncertainties associated with climate-change projections. Whereas the uncertainties of climate forecasts are widely appreciated, the same cannot be said for the approaches that avoid climate forecasts. It is not the case that there is one best approach. The answer to uncertainty is to seek robust conservation plans that work regardless of which approach is taken.

Sceptic priors and climate consensus

2021 ◽  
Author(s):  
Grant McDermott
Keyword(s):  
Climate Change ◽  
Climate Sensitivity ◽  
Bayesian Model ◽  
Bayesian Learning ◽  
Scientific Literature ◽  
Necessary Conditions ◽  
Social Phenomenon ◽  
Climate Data ◽  
Consensus Formation ◽  
The Face

Abstract How much evidence would it take to convince sceptics that they are wrong about climate change? I explore this question within a Bayesian framework. I consider a group of stylised sceptics and examine how these individuals update their beliefs in the face of current and continuing climate change. I find that available evidence in the form of instrumental climate data tends to overwhelm all but the most extreme priors. Most sceptics form up dated beliefs about climate sensitivity that correspond closely to estimates from the scientific literature. However, belief convergence is a non-linear function of prior strength. It thus becomes increasingly difficult to convince the remaining pool of sceptics. I discuss necessary conditions for consensus formation under Bayesian learning and show how apparent deviations from the Bayesian ideal still be accommodated within the same conceptual framework. I argue that a generalized Bayesian model thus provides a bridge between competing theories of climate scepticism as a social phenomenon.

scholarly journals Climate change and its impacts: growing stress factors for human societies

2010 ◽  
Vol 92 (879) ◽  
pp. 557-568 ◽  
Author(s):  
Martin Beniston
Keyword(s):  
Climate Change ◽  
Natural Resources ◽  
Life Support ◽  
Climate Impacts ◽  
First Century ◽  
Stress Factors ◽  
Human Beings ◽  
The Face ◽  
Water Quality And Quantity

AbstractThe realization that human beings need to be concerned about the only ‘life-support system’ that the Earth and its environment provides stems perhaps in part from the fact that, until fairly recently, the evolution of humankind was largely dependent on the quality of the environment and the resources it provides in terms of water, food, and favourable health conditions. These are as vital as ever, despite current levels of technology and apparent resilience in the face of often degraded environments in many parts of the world. Today, the conditions for human sustainability (i.e. water quality and quantity, food security, and health) are potentially under threat as a result of numerous human-induced factors; among these, climate change is certainly one of the more durable aspects of anthropogenic disruptions to natural resources. This article will therefore focus on the possible evolution of climate in the course of the twenty-first century and on a number of key climate impacts that may determine the future course of human societies, as well as issues that may confront them such as rivalries over natural resources and possible environmentally driven conflicts and migrations.

Digital cultures and climate change: ‘Here and now’

2020 ◽  
Vol 1 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Maxwell Boykoff
Keyword(s):  
Climate Change ◽  
First Century ◽  
Changing Climate ◽  
The Face ◽  
Twenty First Century ◽  
Digital Cultures

We are living through momentous times as we confront issues surrounding digital cultures and communications about climate change. There is urgency derived from our recognition that climate change is ‘here and now’. Inequalities of power and access – in both digital cultures and in a changing climate – disadvantage individuals and communities who seek to take actions in the face of climate threats. Via digital cultures, creativity is expanding rather than retracting from the challenge of meeting people where they are on climate change in the twenty-first century. Amid signs of progress and hope, there is much more work to be done.

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