Doctoral Dissertation Research: Avian Taphonomy and Paleoecology of Lowermost Bed II, Olduvai Gorge, Tanzania

在Olduvai景观古人类学项目（OLAPP）联合主任Robert Blumenschine的指导下，Kari Alyssa Prassack将调查坦桑尼亚北部不同湖岸栖息地的现代鸟类骨骼存活情况，然后将这些分类学信息应用于OLAPP从坦桑尼亚Olduvai峡谷175万年前的沉积物中恢复的丰富的鸟类骨骼化石组合。最终目标是提高我们对早期使用石器的人类活动的理解，这些人类的考古遗迹通常与奥杜瓦伊的鸟类骨骼化石同时出现。在地貌学和古生态学研究中使用现代环境，可以确保在重建早期人类过去的环境和生活方式时具有更高的可信度。由于Olduvai的古代景观主要是一个大型盐湖，因此坦桑尼亚大裂谷的几个现代盐碱湖盆地环境被选为实地地点。普拉萨克女士将观察鸟类骨骼在景观中的生存情况如何变化，哪些栖息地最有可能保存鸟类骨骼，以及活鸟类群落的景观分布如何反映在死后的鸟类骨骼沉积中。对以鸟类为食的食肉动物的观察将解决捕食在鸟类骨骼存活中的作用，同时提供许多小型食肉动物（如几只，genet, ratel）的摄食生态的急需数据。实验室环境中的受控观察将确定来自不同湖盆生境的水和土壤如何改变鸟骨的外观（例如染色、开裂、微生物活动），补充现场数据。这些数据将用于了解不同的物理和生态过程（如阳光、水和土壤化学、捕食风险）如何不同地影响整个景观中现代鸟类骨骼的存活。结果将被整合到OLAPP现有的OLAPP模型中，该模型描述了Olduvai古人类生活的环境，以便更好地了解他们在古景观中的活动。对奥杜瓦伊发现的其他脊椎动物化石进行广泛的地层学分析，为人类土地利用提供了重要信息。这将是第一次使用奥杜瓦伊的鸟类化石进行分类分析。这里采用的实地方法结合了野生动物行为学、景观生态学和地学方面的既有方法和新方法，这是一个确保跨学科合作的方向。这项研究的结果将在Olduvai以外具有广泛的适用性，与许多古生物和考古地点有关，即使是那些化石鸟类高度碎片化和/或难以识别到更高分类水平的地方。作为OLAPP在坦桑尼亚进行的长期研究项目的一部分，该项目将进一步推动OLAPP在实地方法和数据收集方面培训坦桑尼亚国民的努力。作为博士论文项目，NSF奖将协助Kari Prassack的研究生培训。

Under the supervision of Robert Blumenschine, Co-Director of the Olduvai Landscape Paleoanthropology Project (OLAPP), Kari Alyssa Prassack will investigate modern bird bone survivorship in various lake margin habitats in northern Tanzania, and then apply this taphonomic information to the rich fossil bird bone assemblages recovered by OLAPP from 1.75 million year old deposits at Olduvai Gorge, Tanzania. The ultimate goal is to improve our understanding of the activities of early stone-tool-using hominins, whose archaeological remains commonly co-occur with fossil bird bone at Olduvai.The use of modern environments for taphonomic and paleoecological studies ensures a higher level of confidence when reconstructing past environments and lifestyles of early hominins. Since a large saline lake dominated Olduvai's ancient landscapes, several modern saline/alkaline lake basin environments in the Rift Valley of Tanzania have been selected as field sites. Ms. Prassack will observe how bird bone survivorship varies across the landscape, which habitats are most likely to preserve bird bone, and how the landscape distribution of the living bird community is reflected in post-mortem bird bone deposition. Observations of carnivores feeding on birds will address the role of predation in bird bone survivorship, while bringing much needed data on feeding ecology of many smaller-bodied carnivores (e.g. serval, genet, ratel). Controlled observations in laboratory settings will determine how water and soils from different lake basin habitats alter the appearance of bird bone (e.g. staining, cracking, microbial activity), supplementing the field data. These data will be used to understand how various physical and ecological processes (e.g. sun, water and soil chemistry, predation risk) differentially affect the survivorship of modern bird bone across the landscape. Results will be integrated into existing OLAPP models of the environments in which ancient hominins at Olduvai lived in order to provide a greater understanding of their activities across the paleolandscape. Extensive taphonomic analysis of Olduvai's other fossil vertebrates has provided important information on hominin land use. This will be the first taphonomic analysis using the fossil birds at Olduvai.The field methods being employed here combine established and novel methods in wildlife ethology, landscape ecology, and taphonomy, a direction that ensures interdisciplinary collaborations. Results of this study will have broad applicability beyond Olduvai, being relevant to numerous paleontological and archaeological localities, even those where fossil birds are highly fragmented and/or difficult to identify to higher taxonomic levels. As part of OLAPP's long term, ongoing research project in Tanzania, this project will further OLAPP's efforts to train Tanzanian nationals in field methods and data collection. As a doctoral dissertation project, the NSF award will assist in the graduate student training of Kari Prassack.