Eastern Waterfowl Breeding Ground Survey

U.S. Fish and Wildlife Service

Canadian Wildlife Service
http://www.ec.gc.ca/

Project name: The State of Canada's Birds

Goals : Estimate the size of the breeding populations of waterfowl species

Dataset summary : Composite estimates of waterfowl breeding populations using hierarchical modelling approach to combine fixed-wing and helicopter aerial counts.

Year started : 1996

Years (comments) : Helicopter plot counts and derived estimates starting in 1996 but composite estimates starting in 2004. Ongoing.

Season(s) and frequency : annually during the breeding season

Frequency : Annually

Geographic area covered : Ontario, Quebec, Labrador, Newfoundland, Nova Scotia, Prince Edward Island, New Brunswick

Primary species covered : Ducks and geese but originally designed to cover the core breeding range of the American Black duck.

Sampling Design : Helicopter plots were selected according to a systematic design using the UTM (Mercator) grid system in Ontario and Québec, and to a stratified random method in the Atlantic Provinces. Plot are surveyed on a rotating panel design whereby all plots are surveyed at least once over a 3-year period and all plots are surveyed twice over a 4-year period (see Bordage et al. 2017). The airplane survey use a stratified sampling approach were the area is divided into strata and the number of transects is greater and the transects are more closely spaced in areas with greater average duck densities (see Smith 1995).

Field methods : Helicopter plot surveys and fixed-wing aerial transects For helicopter surveys, survey altitude vary between 15 and 50 m above ground level based on safety considerations. The helicopter speed ranged between 100 km h-1 and 30 km h-1 depending on the type of habitat being surveyed. The survey crew consisted of the pilot and three observers, one sitting in the front with the pilot and the other two sitting in the rear. For all waterfowl flocks observed by the crew, the count, species, sex composition for dimorphic species and location of the observations are recorded on a portable computer via a GPS-voice recording software For airplane survey, an aerial crew consists of the pilot and an observer; both crew members are biologists trained to count birds. Waterfowl on the transects are surveyed from the airplane. Traveling about 193 km/hr at a height of 30-50 m above the ground. All identified waterfowl within 200 m of each side of the aircraft are counted. The pilot is responsible for the left side and the observer for the right side of the transect. All waterfowl that are observed and identified within the transect boundaries are recorde

Analysis methods : Hierarchical modelling approach as described in Zimmerman et al. (2012). Fixed-wing counts are adjusted using Visual Correction Factors based on helicopter detection.