Northern Prairie Wildlife Research Center
Wyoming Cooperative Research Unit, Department of Zoology and Physiology, Box 3166, University Station, Laramie, WY 82071.
During 1991-92, we examined waterbird use on 92 ponds created or reclaimed as a result of mine reclamation and mitigation in northeast Wyoming. Precipitation during 1991 and 1992 was 117% and 78% of normal, respectively. Twelve wetlands went dry before the end of 1991 and never refilled. Another 13 ponds dried up during fall 1992. Most wetlands were shallow ( = 1.29 m), had flat featureless bottoms, and did not intersect ground-water. Average drawdown for wetlands was 30%.
Habitat variables, which included wetland size and configuration, number of wetlands within a basin, distance to nearest wetland, average depth, average drawdown, percent slope, presence of nesting islands, terrestrial vegetation cover and type, aquatic vegetation cover and type, and water quality (pH, hardness, and chloride), were measured and correlated with seasonal (migrating, breeding, and brood rearing) waterfowl abundance and distribution. Mallards (Anas platyrhynchos), blue-winged teal (A. discors), green-winged teal (A. crecca), American wigeon (A. americana), gadwalls (A. strepera), redheads (Aythya ferina), and ring-neck (A. collaris) ducks were the most common ducks seen. Other duck species observed included canvasbacks (A. valisineria), cinnamon teal (Anas cyanoptera), lesser scaup (Aythya affinis), buffleheads (Bucephala albeola), wood ducks (Aix sponsa), ruddy ducks (Oxyura jamaicensis), northern pintails (Anas acuta), common mergansers (Mergus merganser), common goldeneyes (Bucephala clangula), and northern shovelers (Anas clypeata). Canada geese (Branta canadensis) were the most common nesting waterfowl. Mallards and blue-winged teal were the only ducks observed nesting and rearing broods. Canada geese were found on wetlands that were larger ( = 2.09 ha) and were less drawn down ( = 21%) or more permanent than unused wetlands. Canada geese were also found on ponds that were located within wetland complexes (>5 wetlands within 1 km radius). Puddle ducks used ponds that had greater drawdown ( = 42%), had higher amounts of submergent and emergent vegetation, and that were larger ( = 1.44 ha) than unused wetlands. Diving ducks were found on large ponds ( = 1.51 ha), that had steep slopes ( = 11°), and greater amounts of submergent vegetation present.
Densities of migrating, breeding, and broods of ducks were much lower than those reported for plains habitats elsewhere. Created wetlands located in northeast Wyoming are isolated from other wetlands and are not located within major waterfowl migration routes. Isolation may produce an "island effect" and keep these newly created wetlands from being colonized as quickly as wetlands created in other areas.
Management recommendations for the creation of future wetlands include: created wetlands should be in groups or complexes of >5 ponds within 1 km; created wetlands should have an average size >1 ha; aggressive wetland plant propagation should be initiated at created or reclaimed wetlands to increase waterfowl foods; and, created wetlands should have variable depths, drawdowns, and configurations to accommodate the various species and their life requirements.
This research was funded by the Wyoming Game and Fish Department and the Wyoming Cooperative Fish and Wildlife Research Unit.