Migratory Bird Management
Alaska Region



Yukon Delta Aerial Breeding Waterfowl Survey

Aerial surveys of geese nesting in the coastal zone of the Yukon-Kuskokwim delta have been conducted each spring since 1985. The objective of the project was to develop aerial survey procedures that provided an annual index to the number of breeding pairs of cackling geese (Branta hutchinsii), emperor geese (Chen canagica) and greater white-fronted geese (Anser albifrons). Since 1988, others species of birds such as ducks, loons, and gulls have also been recorded by an observer in the back seat. Another objective was to obtain information on the distribution of the birds on the nesting grounds.

The survey was based on a systematic random design. Strip transects 400 meters wide were systematically spaced at 1, 2, 4 or 8 mile intervals from a random start point. Greater survey effort was allocated in areas known to support more geese. These transects extended from the coastline inland to the edge of upland tundra. The transects sampled a survey area that included land from Norton Sound in the north to the mouth of the Kuskokwim River in the south.

Transects were flown following conventions established for breeding ground surveys in North America. A Cessna 206 amphibious aircraft was flown at 85-95 mph and at altitudes of 100-150 feet. A Loran-C and in later years a Global Positioning System was used to navigate the transects. Surveys were flown only in good weather. The pilot and observer in the right seat recorded singles, pairs and flocks of cacklers, emperors, white-fronts, and tundra swans observed in a 1/8 mile strip on each side of the aircraft. An observer in the back seat recorded other species such as ducks, loons, gulls, terns, and grebes. These observations, as well as the start and stop of each transect were recorded on notebook computers connected with the aircraft global positioning system (GPS) receiver and a remote microphone and mouse.

Survey observations were transcribed and data entered into a computer. Population indices for each species have been calculated for each year and population trends over time have also been calculated. Geographic distributions of the species have been mapped using geographic information system software. This information is used by managers when making decisions that may affect waterfowl populations. For the Summary Report of data collected by the back seat observer click on the following link:

Abundance and Trends of Waterbirds on Alaska's Yukon Kuskokwim Delta Coast based on 1988 to 2014 Aerial Surveys.

Report to the Pacific Flyway Committee Coastal zone Yukon-Kuskokwim Delta Goose Survey of geese, swans, and sandhill cranes 2014.

Last Updated: March 2, 2015