Eastern Waterfowl Survey (EWS25)

The Canadian Wildlife Service (CWS) Eastern Waterfowl Survey (EWS) uses helicopters to annually survey breeding waterfowl on square plots located either systematically (Ontario and Québec) or semi-randomly (Atlantic region) within the breeding range of the American Black Duck. The initial goal of the EWS was to address objectives specific to the American Black Duck under the Black Duck Joint Venture (BDJV, a component of the North American Waterfowl Management Plan), while also surveying and generating reliable indices for trends of all waterfowl species with similar breeding phenology nesting within the Black Duck’s range in eastern Canada.

Following pilot surveys from 1985-1989, EWS was initiated in 1990. The survey design (plot size, number, and survey frequency) changed multiple times in the early years. From 1990-1992, the survey design included 202 10x10 km (100 km²) plots surveyed annually. From 1993-1994, the number of 100 km² plots in Ontario and Québec were reduced by nearly half based on an optimal allocation technique, leaving 143 plots to be surveyed annually. In 1995, the number of 100 km² plots was further reduced to 92 for an annual survey. Beginning in 1996, the survey design was modified by reducing plot size to 5x5 km (25km²), increasing the plot number to 304, implementing a rotational design whereby all plots were surveyed at least once over a 3-year period and all plots were surveyed twice over a 4-year period, and distributing plots among four strata based on Black Duck population units (64–84 plots/stratum). The locations and number of plots have slightly shifted since 1996, with a total of 332 unique plots having been surveyed at least once since the EWS began.

This dataset (EWS25) contains all data collected with the current survey design of 25 km² plots, including data from 1990-1995 subsetted to the 25 km² plot extents (with the exception of plots in Ontario which include all observations from the full 100 km² plot extents from 1990-1995).

Complete bilingual metadata including detailed survey protocols and data dictionaries is available in downloadable files.

Organization: Environment and Climate Change Canada | Environnement et Changement climatique Canada

Last modified: 2026-06-15T14:54:35.457929