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.
Note that data from the 1968, 1975, 1980, 1985, 1990, 1995, 2000, 2005, 2010, and 2015 statewide Alaska Trumpeter Swan Surveys are also archived as a separate project in the USFWS Alaska Regional Data Repository. That project archive includes additional files related to survey design, analyses, and results (including reports and publications) and can be found at: file:\ifw7ro-file.fws.doi.net\datamgt\mbm\mbmwa_006_AK_TRUS_survey.
