International Research Fellowship Program: Population Sex Ratio Bias: Influences of Climate and Consequences for Extinction Risk

格雷森国际研究奖学金计划使美国科学家和工程师能够在国外进行9到24个月的研究。该计划的奖项提供了联合研究的机会，并利用国外独特或互补的设施、专业知识和实验条件。该奖项将支持克里斯汀·L·格雷森博士与新西兰维多利亚大学尼古拉·J·纳尔逊博士合作的为期16个月的研究奖学金。了解气候变化的生态影响是一项紧迫的研究重点。温度对种群动态的显著影响在具有温度依赖性性别决定(TSD)的物种中尤为明显。即使是气候的微小变化也有可能改变鸟巢的温度，并使整个种群的性别比例发生偏差。这项研究项目测量了气候对一种患有TSD的爬行动物种群结构的影响，并确定有偏见的性别比例是否会放大灭绝的风险。首先，他们正在使用新西兰北部的小岛蜥蜴种群来测量自然纬度梯度上当前的种群性别比例。正在研究岛屿上种群结构的变化与1)过去的温度制度，2)可用的热巢小生境，以及3)雌性条件和繁殖力。其次，他们正在使用一种实验方法来确定男性偏见性别比例在短期内改变的互动和行为，以及长期对女性形态和状况的影响。最后，他们将他们的数据与图阿塔拉研究小组的长期人口数据结合起来，形成一个预测矩阵模型。这个模型将使他们能够探索关于性别比偏差和种群过程之间联系的理论问题，并产生对蜥蜴种群生存能力的现实估计。他们的研究测试了气温上升和可用的热巢栖息地对自然种群成人性比偏差程度的影响的假设。他们使用了一种Ib型TSD物种，在这种物种中，较温暖的巢会产生雄性后代，以测试关于种群性别比在将个体互动和社会制度与种群的增长、下降或灭绝联系起来方面所起的作用的理论预测。此外，他们的种群数据将提供亟需的信息，以指导对具有进化、文化和国际意义的濒危物种屠龙的重要剩余种群的保护。这项奖学金还包括通过Spinyback Trust支持当地初级科学教育的机会，以及与马奥里北部岛屿部落合作的机会。

0965096GraysonThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a sixteen-month research fellowship by Dr. Kristine L. Grayson to work with Dr. Nicola J. Nelson at Victoria University in New Zealand. Understanding the ecological impacts of climate change is an urgent research priority. The ability of temperature to dramatically impact population dynamics is particularly apparent in species with temperature-dependent sex determination (TSD). Even small shifts in climate have the potential to alter nest temperatures and bias the sex ratio of an entire population. This research project measures the influence of climate on population structure in a reptile species with TSD, the tuatara (Sphenodon punctatus), and determines if a biased sex ratio amplifies the risk of extinction. First, they are using small island populations of tuatara across northern New Zealand to measure current population sex ratios across a natural latitudinal gradient. The variation in population structure across islands is being examined in relation to 1) past temperature regimes, 2) available thermal nesting microhabitats, and 3) female condition and fecundity. Second, they are using an experimental approach to determine the interactions and behavior altered by a male-biased sex ratio over the short-term and the impact on female morphology and condition over the long-term. Finally, they are combining their data with long-term population data from the tuatara research group to inform a projection matrix model. This model will allow them to explore theoretical questions about the links between a biased sex ratio and population processes, as well as generate realistic estimations of tuatara population viability. Their research tests hypotheses about the influence of rising air temperatures and available thermal nesting habitats on the degree of adult sex ratio bias across natural populations. They use a species with Type Ib TSD, where warmer nests produce male offspring, to test theoretical predictions about the role of population sex ratio in linking individual interactions and the social system to the growth, decline, or extinction of a population. In addition, their population data will provide much needed information to guide the conservation of important remnant populations of tuatara, a threatened species of evolutionary, cultural, and international significance. This fellowship also includes opportunities to support local primary science education through the Spinyback Trust and work with the northern island tribes of the Mâori.