Journey North - Barn Swallow observations by volunteer community scientists across Central and North America (2000-2020)

This data package contains Barn Swallow migration data consisting of 3,836 total observational reports from 2000 - 2020 across North America and Central America. These data were collected by 1,320 community scientists for Journey North, a crowdsourced participatory science program of the University of Wisconsin-Madison Arboretum. The Journey North Barn Swallow Project is an ongoing study of Barn Swallow phenology conducted at broad spatial and temporal scales. Since 2000, community scientists have tracked first arrival dates of Barn Swallows (Hirundo rustica) in the United States. Observers also provide estimates of the number of birds sighted. However, observers do not follow standardized methods for counting species observed. Observers do not observe at set times of the day, do not repeat observations regularly, and are not required to provide the length of time during which a specified number of species observed were counted. Therefore, it is recommended that this dataset be analyzed to indicate presence not abundance. Researchers are encouraged to read the rich information provided by volunteers in their comments. These comments provide qualitative information about observational reports. Researchers are also encouraged to refer to submitted photographs that also provide context for observational reports. The Journey North Barn Swallow Project dataset is hosted by the University of Wisconsin-Madison Shared Web Hosting Service.本数据包包含家燕（Barn Swallow）迁徙数据集，涵盖2000年至2020年间北美及中美洲地区共计3836份观测报告。该数据集由1320名社区科学家为“Journey North”项目收集而成，“Journey North”是威斯康星大学麦迪逊分校植物园推出的众包参与式科学计划。“Journey North 家燕项目”是一项在大空间与时间尺度上开展的家燕物候学长期研究。自2000年起，社区科学家便持续追踪美国境内家燕（Hirundo rustica）的首次抵达日期，观测者同时会提供目击个体数量的估算值。但观测者未遵循标准化的物种计数流程：既未在固定时段开展观测，也未定期重复观测，且无需提供计数指定观测物种的持续时长。因此，建议本数据集仅用于分析物种存在情况，而非种群丰度。建议研究人员查阅志愿者在备注中提供的丰富信息，此类备注可为观测报告提供定性补充资料。同时建议研究人员参考提交的观测照片，这些照片也可为观测报告提供相关背景信息。“Journey North 家燕项目”数据集由威斯康星大学麦迪逊分校共享网络托管服务平台托管。