Alaska Swan Database 1968-2015

In the 1960s, US Fish and Wildlife Service (USFWS) Alaska Region Migratory Bird Management (MBM-AK) developed a protocol for aerial Trumpeter Swan (Cygnus buccinator) and Tundra Swan (C. columbianus) abundance surveys in Alaska that was used by several government agencies and private entities through 2015. This standardized survey protocol allowed data collected by these diverse organizations to be stored together in a common digital archival system called the Alaska Swan Database, which is maintained by MBM-AK. Contributions to the database ranged from relatively small, localized surveys to the statewide quinquennial Alaska Trumpeter Swan Survey. Survey timing was either the spring nesting period or late summer before cygnets fledged. A sample unit consisted of one entire USGS 1:63,360 topographic map, or a complete one-quarter block of a 1:63,360 map. A quarter block consisted of the NW, NE, SE, or SW quadrant of a map. Swan observations were recorded as a single adult, adult pair, single with nest (spring only), pair with nest (spring only), single with brood, pair with brood, or flock of adults, with cygnets and flocked swans enumerated. The geographic coordinates were also recorded for each observation.

20世纪60年代，美国鱼类及野生动物管理局（US Fish and Wildlife Service, USFWS）阿拉斯加区域迁徙鸟类管理处（Migratory Bird Management, MBM-AK）制定了针对阿拉斯加地区号手天鹅（Cygnus buccinator）与苔原天鹅（C. columbianus）种群数量的空中调查规程。该规程自制定起至2015年，被多家政府机构与私营实体广泛采用。这套标准化调查规程可将上述不同机构采集的调查数据，统一存储于由MBM-AK维护的通用数字存档系统——“阿拉斯加天鹅数据库”（Alaska Swan Database）中。该数据库的收录范围覆盖广泛，既包括小规模的本地化调查项目，也涵盖覆盖全州的五年一度阿拉斯加号手天鹅专项调查。调查时段可选春季筑巢期，或是幼天鹅具备飞行能力前的晚夏时段。调查样区为单幅美国地质调查局（USGS）1:63,360比例尺地形图，或是该地形图完整的四分之一区块，即西北、东北、东南或西南象限。天鹅观测记录包含以下类别：单只成鸟、成鸟配对个体、单只成鸟带巢（仅春季适用）、成鸟配对带巢（仅春季适用）、单只成鸟带雏群、成鸟配对带雏群，或是成鸟集群，同时需统计幼天鹅与集群天鹅的具体数量。每项观测均需同步记录对应的地理坐标。