Observer and automated estimation data from drone-based imagery of blackbird flocks foraging in commercial sunflower

We used drones to capture images of mixed-species blackbird (Icteridae) flocks damaging sunflower (Helianthus annuus) in North Dakota. Images consisted of an airborne flock with a sky background, creating a strong color contrast for automated bird detection and counting. We analyzed imagery from 60 flights using ImageJ and obtained automated counts. We also asked 20 biologists, ranging from 0-25 years of self-reported experience, to provide estimates for all 60 images in a single sitting. They were asked to make quick estimates (5-10 seconds per photo), to count birds within the sky background, and to zoom in on photos when needed. Photos were randomly ordered and all biologists were given photos in the same order. This study was implemented between September 2021 through October 2022 in multiple counties in North Dakota, USA where blackbird damage to sunflowers is prevalent. This data publication contains the data and R code used to analyze these data as well as the 60 drone images.We designed the study to evaluate the role of flock size, biologist experience, and photo order on the ability of a biologist to make estimates close to the automated count.For more information about this study and these data, see Duttenhefner and Klug (2025). These data were published on 01/22/2025. On 03/12/2025, the metadata was updated to include reference to newly published article.

本研究使用无人机拍摄了美国北达科他州混合种群拟鹂科（Icteridae）黑鸟群啃食向日葵（Helianthus annuus）的航拍影像。所获影像均为以天空为背景的空中鸟群，色彩对比度显著，可用于自动化鸟类检测与计数。本研究通过ImageJ（ImageJ）软件处理60次飞行任务采集的影像，得到自动化计数结果。同时邀请20名自述从业年限为0至25年的鸟类学家，一次性完成全部60张影像的鸟类数量估算：要求估算者快速完成计数（每张照片耗时5至10秒），仅统计天空背景范围内的鸟类，必要时可放大影像细节。所有影像均按随机顺序排列，且全部参与估算的鸟类学家收到的影像顺序保持一致。本研究于2021年9月至2022年10月间，在美国北达科他州多个黑鸟啃食向日葵灾情频发的县域开展。本数据集出版物包含用于分析上述影像的实验数据、R语言分析代码，以及全部60张无人机航拍影像。本研究旨在探究鸟群规模、鸟类学家从业经验以及影像排序，对鸟类学家做出接近自动化计数的数量估算的能力的影响。如需了解本研究与数据集的更多细节，请参阅Duttenhefner与Klug（2025）的相关文献。本数据集于2025年1月22日正式发布。2025年3月12日，本数据集的元数据已完成更新，新增了已发表相关论文的引用信息。