Doctoral Dissertation Research: Using GPS to Track Vultures in Texas

博士论文研究：使用 GPS 追踪德克萨斯州的秃鹫

• 批准号: 1203680
• 负责人: Michael Leitner
• 金额: $ 1.2万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1203680&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Using; GPS

Vultures are catalysts of the decomposition process, but their scavenging is underreported in the academic literature. Moreover, forensic scientists have realized that some vultures will feed on human cadavers in addition to road-kill, thereby complicating time-since-death estimations. Research from Texas State University's Forensic Anthropology Research Facility (FARF) has shown that vultures arrive early during the decomposition process and leave few clues to indicate their prior scavenging presence. As a result, one option to aid law-enforcement during medical-legal investigations involving unidentified human remains will be to identify vultures' preferred and most likely scavenging environments. This doctoral dissertation research project will use global positioning system (GPS)-based satellite telemetry to track vultures in order to analyze and compare the spatial distribution of vulture scavenging behavior at FARF versus vulture scavenging behavior at other non-forensic locations and to establish a predictability model of likely vulture scavenging habitats using remote sensing techniques and spatial and temporal statistics. The doctoral student will attach 45-gram GPS transmitters to vultures. These transmitters will record the vultures' locations every hour for six months. The vulture locational data will be entered into a geographic information system (GIS) to isolate probable vulture scavenging locations using spatial analytic methods, including descriptive statistics, rigorous statistics for hotspot analysis, kernel density estimations, and time-space analysis. A predictability model of vulture scavenging locations will be created using a range of variables, including land cover, distance to roads, and climate data obtained from nearby weather stations. The student will test the hypothesis that land elevation and distance to water will have the greatest impact and that FARF is a vulture scavenging hotspot regardless of the underlying geography. Data from locations where vultures are observed scavenging in the wild will be used to validate the model.This research project differs from other vulture scavenging studies in that the vultures in question are feeding on human cadavers rather than road kill. No other study has ever investigated the spatial distribution of vultures that are known to scavenge on human cadavers. Moreover, GPS wildlife tags combined with GIS technologies have enhanced the scope at which animals can be studied. One remaining challenge is identifying a method that will allow researchers to obtain discrete point data with a continuous observational history for a specific animal behavior such as scavenging. Vultures are excellent research subjects for testing, because they are soarers rather than fliers and they spend the majority of their day in the air. Combining this behavior with the ability to obtain hourly locational data from the GPS transmitters, will allow for the opportunity to discern geographic data linked to specific vulture activities. This project will generate fundamental advances of scientific knowledge by using GPS and GIS to provide an enhanced understanding of vulture scavenging. Furthermore, the results will identify the geographic features associated with probable vulture scavenging locations, thereby contributing to forensic investigation efficiency and accuracy, aviation safety, and vulture conservation. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.

秃鹫是分解过程的催化剂，但学术文献中对它们的食腐行为却鲜有报道。此外，法医科学家已经意识到，一些秃鹫除了以道路死亡为食外，还会以人类尸体为食，从而使死亡时间估计变得复杂。 德克萨斯州立大学法医人类学研究机构 (FARF) 的研究表明，秃鹫在分解过程中很早就到达，并且几乎没有留下任何线索来表明它们之前的食腐行为。 因此，在涉及身份不明的人类遗骸的医学法律调查期间，协助执法的一个选择是确定秃鹫最喜欢和最有可能的觅食环境。 本博士论文研究项目将使用基于全球定位系统（GPS）的卫星遥测技术来跟踪秃鹫，以便分析和比较 FARF 秃鹰食腐行为与其他非法证地点秃鹫食腐行为的空间分布，并利用遥感技术和时空统计数据建立可能的秃鹫食腐栖息地的可预测模型。 博士生将给秃鹫安装 45 克的 GPS 发射器。 这些发射器将在六个月内每小时记录秃鹫的位置。 秃鹫位置数据将被输入地理信息系统（GIS），利用空间分析方法（包括描述性统计、热点分析的严格统计、核密度估计和时空分析）来隔离可能的秃鹫食腐位置。 将使用一系列变量（包括土地覆盖、距道路的距离以及从附近气象站获得的气候数据）创建秃鹫食腐地点的可预测模型。 学生将测试以下假设：陆地海拔和距水域的距离影响最大，并且无论底层地理位置如何，FARF 都是秃鹫的食腐热点。 来自观察到秃鹫在野外觅食的地点的数据将用于验证该模型。该研究项目与其他秃鹫食腐研究的不同之处在于，所讨论的秃鹫以人类尸体为食，而不是道路上的猎物。 没有其他研究调查过以人类尸体为食的秃鹰的空间分布。 此外，GPS野生动物标签与GIS技术相结合扩大了动物研究的范围。 剩下的一个挑战是找到一种方法，使研究人员能够获得具有特定动物行为（例如食腐行为）的连续观察历史的离散点数据。 秃鹫是极好的测试研究对象，因为它们是翱翔者而不是飞行者，而且它们一天的大部分时间都在空中度过。 将这种行为与从 GPS 发射器获取每小时位置数据的能力相结合，将有机会辨别与特定秃鹫活动相关的地理数据。 该项目将通过使用 GPS 和 GIS 来加深对秃鹫食腐行为的了解，从而推动科学知识的基础进步。 此外，结果将确定与可能的秃鹫觅食地点相关的地理特征，从而有助于法医调查的效率和准确性、航空安全和秃鹫保护。 作为博士论文研究改进奖，该奖项还将为有前途的学生建立强大的独立研究生涯提供支持。