Bison population surveys in Yellowstone National Park (USA): 1970-1997

This study presents data from aerial surveys conducted in Yellowstone National Park spanning from 1970 to July 1997, aimed at monitoring the bison population. Surveys were initially conducted four times per year from 1970 to 1990, with a consistent pilot and observer, weather permitting. In 1991, the frequency increased to 9-10 surveys per year. Ideal flying conditions required clear-to-partly-cloudy skies and minimal wind, typically in the early morning to avoid stronger winds later in the day. The flight path commonly began in the northern range and proceeded sequentially southward, though weather conditions such as wind or ground fog sometimes necessitated route adjustments. In instances where surveys could not be completed in a single day, the remaining areas were surveyed the following day, and data were combined. During the early years, data from an elk researcher were sometimes used for the northern range when timing allowed, minimizing overlap in efforts. The objective of the su..., The study area encompassed most of Yellowstone National Park, USA. Aerial survey efforts concentrated on the locales used by the mixed groups (cows with young, usually some mature bulls). Historically, the winter locales used by bison occupied three areas designated the northern range (Lamar Valley), Pelican Valley, and Mary Mountain. The latter encompassed both the centrally located Hayden Valley and the Firehole to the west as one wintering unit because of the movements in both directions across Mary Mountain. Beginning in the 1980’s as bison use patterns began to change, the west side was considered as part of the Mary Mountain geographic unit. Because adult bulls may wander widely, extra efforts were not made to locate these scattered individuals. The data span 1970 through July 1997. There were four aerial surveys per year (Piper Supercub, same pilot and observer with few exceptions), weather, and desired timing permitting from 1970 through 1990. Thereafter surveys increased to 9-1..., , # Bison population surveys in Yellowstone National Park (USA): 1970-1997 Dataset DOI: [10.5061/dryad.2bvq83c25](10.5061/dryad.2bvq83c25) ## Description of the data and file structure # *Collection Metadata* The data span 1970 through July 1997. There were four aerial surveys per year (Piper supercub, same pilot and observer with rare exceptions), weather and desired timing permitting from 1970 through 1990. Thereafter surveys increased to 9-10 per year, circumstances permitting. Flying weather required reasonably wind-free, clear-to-partly-cloudy conditions park-wide, beginning 0800-0900 usually to be ahead of the strong winds that often developed later in the day. Surveys most commonly began with the northern range and proceeded sequentially toward the east boundary and upper Lamar, Mirror Plateau and Pelican Valley, Hayden Valley, the Firehole, and the west side. However wind and/or ground-fog over open valleys sometimes required a change of route. The same factors occasionally d...,本研究呈现了1970年至1997年7月间在美国黄石国家公园开展的航空调查数据，旨在监测美洲野牛种群动态。1970年至1990年期间，调查每年开展四次，在天气条件许可时，由固定的飞行员与观测员执行任务。1991年起，调查频次提升至每年9至10次。理想的飞行作业条件为晴朗至多云天气且风速极低，通常选择清晨时段开展作业，以规避当日晚些时候出现的强风。常规飞行航线以北部区域为起点，随后依次向南推进，但受大风或地面雾等天气因素影响时，有时需调整航线。若单日无法完成全部调查，则剩余区域于次日补测，并合并两日采集的数据。调查初期，若时间许可，北部区域的部分数据会借用麋鹿研究人员的观测结果，以减少作业重复。 本次研究的调查范围涵盖美国黄石国家公园的绝大部分区域。航空调查的重点区域为混合种群（带幼崽的母牛群，通常伴随若干成年公牛）的活动区域。历史上，美洲野牛的冬季活动区域分为三处：北部区域（拉马尔山谷）、佩利肯山谷与玛丽山区域。由于野牛会在玛丽山两侧往返活动，玛丽山区域将中部的海登山谷与西侧的火洞河区域整合为一个冬季活动单元。20世纪80年代起，随着野牛活动模式发生变化，西侧区域被纳入玛丽山地理单元。鉴于成年公牛活动范围极广，因此未额外投入精力搜寻这些分散的个体。 本数据集覆盖1970年至1997年7月的观测数据。1970年至1990年期间，调查每年开展四次，采用派珀超级幼兽（Piper Supercub）轻型固定翼飞机，除极少数情况外均由同一飞行员与观测员执行任务，需满足天气与预期作业时间要求。此后，在条件允许的情况下，调查频次提升至每年9至... # 美国黄石国家公园美洲野牛种群航空调查（1970-1997） 数据集DOI：10.5061/dryad.2bvq83c25 ## 数据与文件结构说明 ### 采集元数据 本数据集覆盖1970年至1997年7月的观测数据。1970年至1990年期间，调查每年开展四次，采用派珀超级幼兽（Piper Supercub）轻型固定翼飞机，除极少数情况外均由同一飞行员与观测员执行任务，需满足天气与预期作业时间要求。此后，在条件允许的情况下，调查频次提升至每年9至10次。飞行作业需满足园区范围内风速适中、晴朗至多云的天气条件，通常于每日08:00-09:00开始作业，以规避当日晚些时候常出现的强风。常规调查航线以北部区域为起点，依次向东边界、拉马尔河上游、镜像高原与佩利肯山谷、海登山谷、火洞河区域及西侧区域推进。但开阔山谷区域出现大风或地面雾时，有时需调整航线。受相同因素影响，偶尔...