Salt Lake straddles the border of South Dakota and Minnesota. The Salt Lake IBA is small and includes only the Minnesota portion of this habitat. Salt Lake is the only alkaline lake in the state of MN (it is 1/3 as salty as sea water) and as such, attracts a remarkable variety of birds. Located in Lac Qui Parle County, 3 miles south of Marietta, this 312 acre lake is known as one of the state?s top birding spots, supporting a large diversity of shorebirds and waterfowl. From Marietta, go south for 3 miles on County Highway 7, drive 1 mile west on a gravel township road to a ?T? intersection that overlooks Salt Lake, continue south (left) for about ¼ mile to access parking area and viewing deck.
This IBA is focused predominately around the Salt Lake Wildlife Management Unit (WMA) but includes some private lands and is adjacent to USFWS ownership. The WMA consists of two separate units, the larger, main unit, is 769 acres and includes the lake. The smaller, northern unit is 11 acres. Since the acquisition of this WMA, the DNR has converted cropland to grasses, creating nesting habitat for waterfowl and grassland species such as Western Meadowlarks and Sedge Wrens. In addition to the DNRs management activities, adjacent landowners have put several hundred acres into the Conservation Reserve Program and the U.S. Fish and Wildlife Service owns most of the lake's South Dakota portion.
The combination of the naturally occurring alkaline soils in the area with the fact that the lake has no natural outlet makes this the only alkaline lake in Minnesota, attracting a variety of unique birds that typically occur farther west such as American Avocets, Hudsonian Godwits, Marbled Godwits, and Western Grebes. A total of 141 species have been observed at Salt Lake IBA, including 37 Species of Greatest Conservation Need (SGCN) and 3 Minnesota State Listed Species; the Wilson?s Phalarope (threatened), Forster?s Tern and Short-eared Owl (species of special concern). Each spring and fall, the lake attracts large flocks of waterfowl, shorebirds and waterbirds because of the abundant food resources found here, including sago pondweed and brine shrimp. This IBA is particularly attractive to shorebirds, typically found feeding in the exposed mudflats, including American Golden-plovers, Piping Plovers, various sandpipers, Marbled Godwits, Willets, and Wilson's Phalaropes. At least 21 species (Appendix 1) of waterfowl have been observed here during migration. American White Pelicans, American Coots, and a variety of grebes are also common at Salt Lake.
Flocks of ducks feed in the shallow waters during migration and it is not uncommon to see flocks of Greater White-fronted and Canada Geese estimated in the 1000?s. Mixed species flocks of waterfowl including Mallards, Blue-winged Teals, Ruddy Ducks, and Northern Pintails also congregate in the thousands at Salt Lake during migration.
Shorebirds congregate on the exposed mudflats where fall counts of Killdeer, Pectoral and Semipalmated Sandpiper flocks range from 300-500 individuals. In the summer Wilson?s Phalarope and American Avocet nest at Salt Lake IBA.
Throughout the summer months significant numbers of Eared Grebes can be found nesting within the Salt Lake IBA. During the fall migration American Coots and Franklin?s Gulls also flock to this IBA in the 1000?s.
In August 2011 an observer made the conservative estimate of 6,000 Tree Swallows at Salt Lake. To the observers knowledge there are only 2 high counts in the state that exceed this total: 20,000 in Sherburne County (9/7/1971, Loon 44:13) and 12,000-15,000 at Howard Lake in Wright County (8/18/1968, Loon 75:95). Smaller Tree Swallow flocks have been observed at Salt Lake in other years. The lake conditions producing large insect hatch years attracting sizable flocks of Tree Swallows do occur yet are irregular.
Wilson?s Phalaropes (threatened) have been documented breeding at Salt Lake IBA in low water level years. Numbers of breeding pairs is unknown.
Salt Lake first came to the notice of the birding community as a result of reports from Mrs. C. E. Mae Peterson (1876-1960) of Madison, Minnesota. Her observations were regularly reported to The Minnesota Ornithologist?s Union (MOU) and Dr. Thomas S. Roberts, author of Birds of Minnesota. As a pioneer bird bander, Mae Peterson banded over 15,000 individual birds of 120 species in her 27 years of work.
The MOU held its first meeting in Madison, MN in the spring of 1963 beginning a long and rich tradition of visiting the area each year in April to enjoy the birds of Salt Lake and surrounding area. The MN DNR purchased about 300 acres if surrounding land in 1973 and has since added 480 acres more, creating food and nesting habitat for birds and other wildlife.
This lake, which fluctuates from completely dry to approximately 300 acres at its high water mark, is the most alkaline body of water in the state. It is about 1/3 as salty as sea water. It hosts extensive beds of sago pondweed, a favorite food of waterfowl and zooplankton, principally red crustacean, a favorite food of shorebirds.
More than 150 species of bird have been documented at Salt Lake WMA, including the first state record of a Western sandpiper found by Walter J. Breckenridge in early September 1960. Other records include American Avocet, Black-necked Stilt, Piping Plover, Red Phalarope, Sabien?s Gull, Lark Bunting, Smith?s Longspur, LeConte?s Sparrow, Henslow?s Sparrow, Ferruginous Hawk, and Short-eared Owl. When the sago is right, Eared Grebes may have a nesting colony here.
The majority of Salt Lake IBA is owned by the Minnesota Department of Natural Resources, so threats to area are relatively minimal. Most of the remaining land included in the IBA is under conservation easement with a private landowner. The major threats that could impact Salt Lake IBA include the abandonment of the conservation easement agreement and transition of those lands back to agriculture, which is unlikely but uncertain due to projected changes to CRP lands included in the upcoming Farm Bill.
Aquaculture is also a threat to the Salt Lake on high water level years when minnow dealers have been known to plant fish.
Agricultural run-off from surrounding areas is also a concern. The threat of pesticide use is potentially compounded at this site because this lake has no natural outlet.