Waterfowl Model Info
This information is excerpted and modified from the final report, which contains the full explanation and rationale for the scoring criteria.
Waterfowl Scoring formula
There are two formulas for calculating waterfowl scores, one for inland areas within 25 km of Lakes Michigan, Huron, Erie and Ontario and connecting waters and one for open waters of Lakes Michigan, Huron, Erie, Ontario and connecting waters. Waterfowl score (inland) = score for landcover type associated with suitable habitat + score for amount of wetland cover within 3 km radius of suitable landcover type + score for patch size + score for adjacent cover type within 100 m of suitable landcover type. Waterfowl score (open waters of Great Lakes and connecting waters) = score based on Great Lakes water depth (bathymetry).
Table 3. Conservation priority scores for waterfowl stopover habitat within 25 km of Lakes Michigan, Huron, Erie, Ontario and connecting water bodies.
Waterfowl stopover attributes: Inland
1. Landcover classified as suitable habitat. Source data: CCAP(US 2006) & PLC (1999) for landcover, and STATSGO (US) & SLR (Canada) for hydric soils.
- 1 = Mixed emergent marsh adjacent to open water
- 0.75 = Open water or emergent marsh, not adjacent
- 0.25 = Palustrine forested wetlands, agricultural fields with hydric soils
2. Amount of wetland cover within 3 km radius of suitable landcover type. Source data: CCAP (US 2006) and PLC (Canada 1999) – applied to any pixels scoring 0.25 or higher in suitable habitat score.
- 1 = >40% wetland cover in 3 km radius window
- 0.5 = 15-40% wetland cover
- 0.25 = less than 15% wetland cover
3. Patch size (patch can include more than one of the “suitable habitat” landcover types shown above) Source data: same as suitable habitat.
- 1 = ≥16 ha (40 acres)
- 0.5 = ≥1 ha (2.5 acres) and less than 16 ha (40 acres)
- 0.25 = less then 1 ha (2.5 acres)
4. Adjacent cover type with in 100 m of the pixel of suitable habitat. Describes presence/absence of a buffer from developed areas or forests.Source data: same as suitable habitat.
- 1 = Undeveloped, non-forest
- 0.5 = Undeveloped, forest
- 0 = Developed; agricultural fields with hydric soils
5. Great Lakes water depthSource data: NOAA Bathymetry
- 1 = less than 4 meters
- 0.5 = 4-6 meters
- 0.25 = greater than 6 meters ≤30 m
- 0 = greater than 30 m
Waterfowl stopover attributes: Open waters of Great Lakes and connecting waters
1. Great Lakes water depthSource data: NOAA Bathymetry
- 4 = <4 meters
- 3 = 4-6 meters
- 2 = >6 meters and ≤30 meters
- 0 = >30 meters
Please keep the following in mind when using the Waterfowl Model:
The distribution of waterfowl in the open waters of the Great Lakes is poorly known. However, recent work (Norris and Lott 2012) indicates that many waterfowl are concentrated closer to the shores of Lake Erie than in offshore waters.
Anthropogenic disturbances including shipping lanes, marinas, public access sites to water, boating traffic and hunting can substantially modify use of otherwise suitable habitat by reducing the amount of time available for foraging or by displacing birds (Knapton et al. 2000, Schummer and Eddelman 2003, Pease et al. 2005, Dooley et al. 2010), but we did not have regionally consistent datasets for these and so did not model their influence. These disturbances should be considered when contemplating action for waterfowl and evaluating the relative quality of different sites.
Setting Stopover Conservation Goals
Although very challenging to establish, articulating conservation goals, based on scientific, operationally realistic, and objective criteria, provides a foundation for estimating the magnitude of work and financial resources needed to achieve conservation results. Although goals are never perfect, they provide important guidelines to direct our work and, when accomplished, when to celebrate and when to focus resources on other conservation goals.
For landbirds, we set a goal of 40% of the landscape be in natural cover within 3 miles (5 km) of a site. The basis for this goal is that several studies, though not all, suggest that landbirds are more crowded, and gain less weight, where less than 15% of the landscape is in suitable habitat compared to landscapes with >15% of suitable habitat and especially with >40% suitable habitat. We think that the scientific literature is sufficiently consistent to articulate this goal to ensure the health of migrating landbirds. We recognize that this goal cannot be achieved everywhere, especially in highly developed urban and some agricultural areas. In these areas goals might focus on improving the quality of existing sites where protecting more habitat is unlikely or can be only be done at very small scales.
We have not yet set goals for shorebirds or waterfowl, as there is insufficient information for shorebirds and waterfowl to define criteria for establishing goals.
More research will improve our ability to establish goals but we now have, at least, a conservation goal to measure our progress toward providing safe passage of landbirds through the Great Lakes region.