These results are based on recent habitat conditions (circa 2010). Also in development are results reflecting future habitat changes as affected by potential sea level rise and human development (2030 and 2080 scenarios).

Intended Uses

This product is intended to serve as a preliminary screening tool to identify subwatersheds that may be promising areas for restoration and protection of black duck habitat. Before undertaking conservation actions, local factors should be considered including availability and quality of wetland habitat, the degree of existing protection, potential methods and costs of wetland restoration, and potential for long-term resilience of habitat in the face of rising sea levels and development pressures.

Description and Derivation

The food energy analysis represents a balance between two factors, energy supply and energy demand:
1) Energy supply: calculated from the extent of black duck wetland habitat in the subwatershed, with energy availability depending on the type and condition of the wetlands present.
2) Energy demand: the amount of energy that could be expected to be consumed by black ducks, while also accounting for presence of other dabbling duck species that compete for the same types of foods in the subwatershed. Estimates are based on the assumption that duck abundance is restored in accordance with the North American Waterfowl Management Plan objectives.

Where the energy supply exceeds the energy demand, the subwatershed can be considered to have surplus energy available. When energy demand exceeds the energy supply, the subwatershed can be considered to have an energy deficit.

Results are displayed in “bins” or quantiles with each bin representing 20% of the subwatersheds. The 20% of the subwatersheds with the greatest food energy surplus are classified as “Highest” priority for protection, and so on, with the 20% of subwatersheds with the least surplus classified as “Lowest” priority. Similarly, the 20% of subwatersheds with the greatest energy deficit are classified as “Highest” priority for restoration or enhancement of habitat.